# coding: utf-8
from __future__ import print_function, unicode_literals

import argparse
import base64
import binascii
import codecs
import errno
import hashlib
import hmac
import json
import logging
import math
import mimetypes
import os
import platform
import re
import select
import shutil
import signal
import socket
import stat
import struct
import subprocess as sp  # nosec
import sys
import threading
import time
import traceback
from collections import Counter

from ipaddress import IPv4Address, IPv4Network, IPv6Address, IPv6Network
from queue import Queue

try:
    from zlib_ng import gzip_ng as gzip
    from zlib_ng import zlib_ng as zlib

    sys.modules["gzip"] = gzip
    # sys.modules["zlib"] = zlib
    # `- somehow makes tarfile 3% slower with default malloc, and barely faster with mimalloc
except:
    import gzip
    import zlib

from .__init__ import (
    ANYWIN,
    EXE,
    MACOS,
    PY2,
    PY36,
    TYPE_CHECKING,
    VT100,
    WINDOWS,
    EnvParams,
)
from .__version__ import S_BUILD_DT, S_VERSION
from .stolen import surrogateescape

try:
    from datetime import datetime, timezone

    UTC = timezone.utc
except:
    from datetime import datetime, timedelta, tzinfo

    TD_ZERO = timedelta(0)

    class _UTC(tzinfo):
        def utcoffset(self, dt):
            return TD_ZERO

        def tzname(self, dt):
            return "UTC"

        def dst(self, dt):
            return TD_ZERO

    UTC = _UTC()


if PY2:
    range = xrange  # type: ignore


if sys.version_info >= (3, 7) or (
    PY36 and platform.python_implementation() == "CPython"
):
    ODict = dict
else:
    from collections import OrderedDict as ODict


def _ens(want )   :
    ret  = []
    for v in want.split():
        try:
            ret.append(getattr(errno, v))
        except:
            pass

    return tuple(ret)


# WSAECONNRESET - foribly closed by remote
# WSAENOTSOCK - no longer a socket
# EUNATCH - can't assign requested address (wifi down)
E_SCK = _ens("ENOTCONN EUNATCH EBADF WSAENOTSOCK WSAECONNRESET")
E_ADDR_NOT_AVAIL = _ens("EADDRNOTAVAIL WSAEADDRNOTAVAIL")
E_ADDR_IN_USE = _ens("EADDRINUSE WSAEADDRINUSE")
E_ACCESS = _ens("EACCES WSAEACCES")
E_UNREACH = _ens("EHOSTUNREACH WSAEHOSTUNREACH ENETUNREACH WSAENETUNREACH")

IP6ALL = "0:0:0:0:0:0:0:0"


try:
    import fcntl

    HAVE_FCNTL = True
except:
    HAVE_FCNTL = False

try:
    import ctypes
    import termios
except:
    pass

try:
    if os.environ.get("PRTY_NO_SQLITE"):
        raise Exception()

    HAVE_SQLITE3 = True
    import sqlite3

    assert hasattr(sqlite3, "connect")  # graalpy
except:
    HAVE_SQLITE3 = False

try:
    import importlib.util

    HAVE_ZMQ = bool(importlib.util.find_spec("zmq"))
except:
    HAVE_ZMQ = False

try:
    if os.environ.get("PRTY_NO_PSUTIL"):
        raise Exception()

    HAVE_PSUTIL = True
    import psutil
except:
    HAVE_PSUTIL = False

try:
    if os.environ.get("PRTY_NO_MAGIC"):
        raise Exception()

    import magic
except:
    pass

if TYPE_CHECKING:
    from .authsrv import VFS
    from .broker_util import BrokerCli
    from .up2k import Up2k

FAKE_MP = False

try:
    if os.environ.get("PRTY_NO_MP"):
        raise ImportError()

    import multiprocessing as mp

    # import multiprocessing.dummy as mp
except ImportError:
    # support jython
    mp = None  # type: ignore

if not PY2:
    from io import BytesIO
else:
    from StringIO import StringIO as BytesIO  # type: ignore


try:
    if os.environ.get("PRTY_NO_IPV6"):
        raise Exception()

    socket.inet_pton(socket.AF_INET6, "::1")
    HAVE_IPV6 = True
except:

    def inet_pton(fam, ip):
        return socket.inet_aton(ip)

    socket.inet_pton = inet_pton
    HAVE_IPV6 = False


try:
    struct.unpack(b">i", b"idgi")
    spack = struct.pack  # type: ignore
    sunpack = struct.unpack  # type: ignore
except:

    def spack(fmt , *a )  :
        return struct.pack(fmt.decode("ascii"), *a)

    def sunpack(fmt , a )   :
        return struct.unpack(fmt.decode("ascii"), a)


try:
    BITNESS = struct.calcsize(b"P") * 8
except:
    BITNESS = struct.calcsize("P") * 8


ansi_re = re.compile("\033\\[[^mK]*[mK]")


BOS_SEP = ("%s" % (os.sep,)).encode("ascii")


surrogateescape.register_surrogateescape()
if WINDOWS and PY2:
    FS_ENCODING = "utf-8"
else:
    FS_ENCODING = sys.getfilesystemencoding()


SYMTIME = PY36 and os.utime in os.supports_follow_symlinks

META_NOBOTS = '<meta name="robots" content="noindex, nofollow">\n'

# smart enough to understand javascript while also ignoring rel="nofollow"
BAD_BOTS = r"Barkrowler|bingbot|BLEXBot|Googlebot|GoogleOther|GPTBot|PetalBot|SeekportBot|SemrushBot|YandexBot"

FFMPEG_URL = "https://www.gyan.dev/ffmpeg/builds/ffmpeg-git-full.7z"

URL_PRJ = "https://github.com/9001/copyparty"

URL_BUG = URL_PRJ + "/issues/new?labels=bug&template=bug_report.md"

HTTPCODE = {
    200: "OK",
    201: "Created",
    202: "Accepted",
    204: "No Content",
    206: "Partial Content",
    207: "Multi-Status",
    301: "Moved Permanently",
    302: "Found",
    304: "Not Modified",
    400: "Bad Request",
    401: "Unauthorized",
    403: "Forbidden",
    404: "Not Found",
    405: "Method Not Allowed",
    409: "Conflict",
    411: "Length Required",
    412: "Precondition Failed",
    413: "Payload Too Large",
    416: "Requested Range Not Satisfiable",
    422: "Unprocessable Entity",
    423: "Locked",
    429: "Too Many Requests",
    500: "Internal Server Error",
    501: "Not Implemented",
    503: "Service Unavailable",
    999: "MissingNo",
}


IMPLICATIONS = [
    ["e2dsa", "e2ds"],
    ["e2ds", "e2d"],
    ["e2tsr", "e2ts"],
    ["e2ts", "e2t"],
    ["e2t", "e2d"],
    ["e2vu", "e2v"],
    ["e2vp", "e2v"],
    ["e2v", "e2d"],
    ["hardlink_only", "hardlink"],
    ["hardlink", "dedup"],
    ["tftpvv", "tftpv"],
    ["smbw", "smb"],
    ["smb1", "smb"],
    ["smbvvv", "smbvv"],
    ["smbvv", "smbv"],
    ["smbv", "smb"],
    ["zv", "zmv"],
    ["zv", "zsv"],
    ["z", "zm"],
    ["z", "zs"],
    ["zmvv", "zmv"],
    ["zm4", "zm"],
    ["zm6", "zm"],
    ["zmv", "zm"],
    ["zms", "zm"],
    ["zsv", "zs"],
]
if ANYWIN:
    IMPLICATIONS.extend([["z", "zm4"]])


UNPLICATIONS = [["no_dav", "daw"]]


DAV_ALLPROP_L = [
    "contentclass",
    "creationdate",
    "defaultdocument",
    "displayname",
    "getcontentlanguage",
    "getcontentlength",
    "getcontenttype",
    "getlastmodified",
    "href",
    "iscollection",
    "ishidden",
    "isreadonly",
    "isroot",
    "isstructureddocument",
    "lastaccessed",
    "name",
    "parentname",
    "resourcetype",
    "supportedlock",
]
DAV_ALLPROPS = set(DAV_ALLPROP_L)


MIMES = {
    "opus": "audio/ogg; codecs=opus",
    "owa": "audio/webm; codecs=opus",
}


def _add_mimes()  :
    # `mimetypes` is woefully unpopulated on windows
    # but will be used as fallback on linux

    for ln in """text css html csv
application json wasm xml pdf rtf zip jar fits wasm
image webp jpeg png gif bmp jxl jp2 jxs jxr tiff bpg heic heif avif
audio aac ogg wav flac ape amr
video webm mp4 mpeg
font woff woff2 otf ttf
""".splitlines():
        k, vs = ln.split(" ", 1)
        for v in vs.strip().split():
            MIMES[v] = "{}/{}".format(k, v)

    for ln in """text md=plain txt=plain js=javascript
application 7z=x-7z-compressed tar=x-tar bz2=x-bzip2 gz=gzip rar=x-rar-compressed zst=zstd xz=x-xz lz=lzip cpio=x-cpio
application msi=x-ms-installer cab=vnd.ms-cab-compressed rpm=x-rpm crx=x-chrome-extension
application epub=epub+zip mobi=x-mobipocket-ebook lit=x-ms-reader rss=rss+xml atom=atom+xml torrent=x-bittorrent
application p7s=pkcs7-signature dcm=dicom shx=vnd.shx shp=vnd.shp dbf=x-dbf gml=gml+xml gpx=gpx+xml amf=x-amf
application swf=x-shockwave-flash m3u=vnd.apple.mpegurl db3=vnd.sqlite3 sqlite=vnd.sqlite3
text ass=plain ssa=plain
image jpg=jpeg xpm=x-xpixmap psd=vnd.adobe.photoshop jpf=jpx tif=tiff ico=x-icon djvu=vnd.djvu
image heic=heic-sequence heif=heif-sequence hdr=vnd.radiance svg=svg+xml
audio caf=x-caf mp3=mpeg m4a=mp4 mid=midi mpc=musepack aif=aiff au=basic qcp=qcelp
video mkv=x-matroska mov=quicktime avi=x-msvideo m4v=x-m4v ts=mp2t
video asf=x-ms-asf flv=x-flv 3gp=3gpp 3g2=3gpp2 rmvb=vnd.rn-realmedia-vbr
font ttc=collection
""".splitlines():
        k, ems = ln.split(" ", 1)
        for em in ems.strip().split():
            ext, mime = em.split("=")
            MIMES[ext] = "{}/{}".format(k, mime)


_add_mimes()


EXTS   = {v: k for k, v in MIMES.items()}

EXTS["vnd.mozilla.apng"] = "png"

MAGIC_MAP = {"jpeg": "jpg"}


DEF_EXP = "self.ip self.ua self.uname self.host cfg.name cfg.logout vf.scan vf.thsize hdr.cf_ipcountry srv.itime srv.htime"

DEF_MTE = ".files,circle,album,.tn,artist,title,.bpm,key,.dur,.q,.vq,.aq,vc,ac,fmt,res,.fps,ahash,vhash"

DEF_MTH = ".vq,.aq,vc,ac,fmt,res,.fps"


REKOBO_KEY = {
    v: ln.split(" ", 1)[0]
    for ln in """
1B 6d B
2B 7d Gb F#
3B 8d Db C#
4B 9d Ab G#
5B 10d Eb D#
6B 11d Bb A#
7B 12d F
8B 1d C
9B 2d G
10B 3d D
11B 4d A
12B 5d E
1A 6m Abm G#m
2A 7m Ebm D#m
3A 8m Bbm A#m
4A 9m Fm
5A 10m Cm
6A 11m Gm
7A 12m Dm
8A 1m Am
9A 2m Em
10A 3m Bm
11A 4m Gbm F#m
12A 5m Dbm C#m
""".strip().split(
        "\n"
    )
    for v in ln.strip().split(" ")[1:]
    if v
}

REKOBO_LKEY = {k.lower(): v for k, v in REKOBO_KEY.items()}


_exestr = "python3 python ffmpeg ffprobe cfssl cfssljson cfssl-certinfo"
CMD_EXEB = set(_exestr.encode("utf-8").split())
CMD_EXES = set(_exestr.split())


# mostly from https://github.com/github/gitignore/blob/main/Global/macOS.gitignore
APPLESAN_TXT = r"/(__MACOS|Icon\r\r)|/\.(_|DS_Store|AppleDouble|LSOverride|DocumentRevisions-|fseventsd|Spotlight-|TemporaryItems|Trashes|VolumeIcon\.icns|com\.apple\.timemachine\.donotpresent|AppleDB|AppleDesktop|apdisk)"
APPLESAN_RE = re.compile(APPLESAN_TXT)


HUMANSIZE_UNITS = ("B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB")

UNHUMANIZE_UNITS = {
    "b": 1,
    "k": 1024,
    "m": 1024 * 1024,
    "g": 1024 * 1024 * 1024,
    "t": 1024 * 1024 * 1024 * 1024,
    "p": 1024 * 1024 * 1024 * 1024 * 1024,
    "e": 1024 * 1024 * 1024 * 1024 * 1024 * 1024,
}

VF_CAREFUL = {"mv_re_t": 5, "rm_re_t": 5, "mv_re_r": 0.1, "rm_re_r": 0.1}

FN_EMB = set([".prologue.html", ".epilogue.html", "readme.md", "preadme.md"])


def read_ram()   :
    # NOTE: apparently no need to consider /sys/fs/cgroup/memory.max
    #  (cgroups2) since the limit is synced to /proc/meminfo
    a = b = 0
    try:
        with open("/proc/meminfo", "rb", 0x10000) as f:
            zsl = f.read(0x10000).decode("ascii", "replace").split("\n")

        p = re.compile("^MemTotal:.* kB")
        zs = next((x for x in zsl if p.match(x)))
        a = int((int(zs.split()[1]) / 0x100000) * 100) / 100

        p = re.compile("^MemAvailable:.* kB")
        zs = next((x for x in zsl if p.match(x)))
        b = int((int(zs.split()[1]) / 0x100000) * 100) / 100
    except:
        pass
    return a, b


RAM_TOTAL, RAM_AVAIL = read_ram()


pybin = sys.executable or ""
if EXE:
    pybin = ""
    for zsg in "python3 python".split():
        try:
            if ANYWIN:
                zsg += ".exe"

            zsg = shutil.which(zsg)
            if zsg:
                pybin = zsg
                break
        except:
            pass


def py_desc()  :
    interp = platform.python_implementation()
    py_ver = ".".join([str(x) for x in sys.version_info])
    ofs = py_ver.find(".final.")
    if ofs > 0:
        py_ver = py_ver[:ofs]

    host_os = platform.system()
    compiler = platform.python_compiler().split("http")[0]

    m = re.search(r"([0-9]+\.[0-9\.]+)", platform.version())
    os_ver = m.group(1) if m else ""

    return "{:>9} v{} on {}{} {} [{}]".format(
        interp, py_ver, host_os, BITNESS, os_ver, compiler
    )


def expat_ver()  :
    try:
        import pyexpat

        return ".".join([str(x) for x in pyexpat.version_info])
    except:
        return "?"


def _sqlite_ver()  :
    try:
        co = sqlite3.connect(":memory:")
        cur = co.cursor()
        try:
            vs = cur.execute("select * from pragma_compile_options").fetchall()
        except:
            vs = cur.execute("pragma compile_options").fetchall()

        v = next(x[0].split("=")[1] for x in vs if x[0].startswith("THREADSAFE="))
        cur.close()
        co.close()
    except:
        v = "W"

    return "{}*{}".format(sqlite3.sqlite_version, v)


try:
    SQLITE_VER = _sqlite_ver()
except:
    SQLITE_VER = "(None)"

try:
    from jinja2 import __version__ as JINJA_VER
except:
    JINJA_VER = "(None)"

try:
    from pyftpdlib.__init__ import __ver__ as PYFTPD_VER
except:
    PYFTPD_VER = "(None)"

try:
    from partftpy.__init__ import __version__ as PARTFTPY_VER
except:
    PARTFTPY_VER = "(None)"


PY_DESC = py_desc()

VERSIONS = (
    "copyparty v{} ({})\n{}\n   sqlite {} | jinja {} | pyftpd {} | tftp {}".format(
        S_VERSION, S_BUILD_DT, PY_DESC, SQLITE_VER, JINJA_VER, PYFTPD_VER, PARTFTPY_VER
    )
)


try:
    _b64_enc_tl = bytes.maketrans(b"+/", b"-_")
    _b64_dec_tl = bytes.maketrans(b"-_", b"+/")

    def ub64enc(bs )  :
        x = binascii.b2a_base64(bs, newline=False)
        return x.translate(_b64_enc_tl)

    def ub64dec(bs )  :
        bs = bs.translate(_b64_dec_tl)
        return binascii.a2b_base64(bs)

    def b64enc(bs )  :
        return binascii.b2a_base64(bs, newline=False)

    def b64dec(bs )  :
        return binascii.a2b_base64(bs)

    zb = b">>>????"
    zb2 = base64.urlsafe_b64encode(zb)
    if zb2 != ub64enc(zb) or zb != ub64dec(zb2):
        raise Exception("bad smoke")

except Exception as ex:
    ub64enc = base64.urlsafe_b64encode  # type: ignore
    ub64dec = base64.urlsafe_b64decode  # type: ignore
    b64enc = base64.b64encode  # type: ignore
    b64dec = base64.b64decode  # type: ignore
    if not PY36:
        print("using fallback base64 codec due to %r" % (ex,))


class NotUTF8(Exception):
    pass


def read_utf8(log , ap  , strict )  :
    with open(ap, "rb") as f:
        buf = f.read()

    try:
        return buf.decode("utf-8", "strict")
    except UnicodeDecodeError as ex:
        eo = ex.start
        eb = buf[eo : eo + 1]

    if not strict:
        t = "WARNING: The file [%s] is not using the UTF-8 character encoding; some characters in the file will be skipped/ignored. The first unreadable character was byte %r at offset %d. Please convert this file to UTF-8 by opening the file in your text-editor and saving it as UTF-8."
        t = t % (ap, eb, eo)
        if log:
            log(t, 3)
        else:
            print(t)
        return buf.decode("utf-8", "replace")

    t = "ERROR: The file [%s] is not using the UTF-8 character encoding, and cannot be loaded. The first unreadable character was byte %r at offset %d. Please convert this file to UTF-8 by opening the file in your text-editor and saving it as UTF-8."
    t = t % (ap, eb, eo)
    if log:
        log(t, 3)
    else:
        print(t)
    raise NotUTF8(t)


class Daemon(threading.Thread):
    def __init__(
        self,
        target ,
        name  = None,
        a  = None,
        r  = True,
        ka   = None,
    )  :
        threading.Thread.__init__(self, name=name)
        self.a = a or ()
        self.ka = ka or {}
        self.fun = target
        self.daemon = True
        if r:
            self.start()

    def run(self):
        if not ANYWIN and not PY2:
            signal.pthread_sigmask(
                signal.SIG_BLOCK, [signal.SIGINT, signal.SIGTERM, signal.SIGUSR1]
            )

        self.fun(*self.a, **self.ka)


class Netdev(object):
    def __init__(self, ip , idx , name , desc ):
        self.ip = ip
        self.idx = idx
        self.name = name
        self.desc = desc

    def __str__(self):
        return "{}-{}{}".format(self.idx, self.name, self.desc)

    def __repr__(self):
        return "'{}-{}'".format(self.idx, self.name)

    def __lt__(self, rhs):
        return str(self) < str(rhs)

    def __eq__(self, rhs):
        return str(self) == str(rhs)


class Cooldown(object):
    def __init__(self, maxage )  :
        self.maxage = maxage
        self.mutex = threading.Lock()
        self.hist   = {}
        self.oldest = 0.0

    def poke(self, key )  :
        with self.mutex:
            now = time.time()

            ret = False
            pv  = self.hist.get(key, 0)
            if now - pv > self.maxage:
                self.hist[key] = now
                ret = True

            if self.oldest - now > self.maxage * 2:
                self.hist = {
                    k: v for k, v in self.hist.items() if now - v < self.maxage
                }
                self.oldest = sorted(self.hist.values())[0]

            return ret


class HLog(logging.Handler):
    def __init__(self, log_func )  :
        logging.Handler.__init__(self)
        self.log_func = log_func
        self.ptn_ftp = re.compile(r"^([0-9a-f:\.]+:[0-9]{1,5})-\[")
        self.ptn_smb_ign = re.compile(r"^(Callback added|Config file parsed)")

    def __repr__(self)  :
        level = logging.getLevelName(self.level)
        return "<%s cpp(%s)>" % (self.__class__.__name__, level)

    def flush(self)  :
        pass

    def emit(self, record )  :
        msg = self.format(record)
        lv = record.levelno
        if lv < logging.INFO:
            c = 6
        elif lv < logging.WARNING:
            c = 0
        elif lv < logging.ERROR:
            c = 3
        else:
            c = 1

        if record.name == "pyftpdlib":
            m = self.ptn_ftp.match(msg)
            if m:
                ip = m.group(1)
                msg = msg[len(ip) + 1 :]
                if ip.startswith("::ffff:"):
                    record.name = ip[7:]
                else:
                    record.name = ip
        elif record.name.startswith("impacket"):
            if self.ptn_smb_ign.match(msg):
                return
        elif record.name.startswith("partftpy."):
            record.name = record.name[9:]

        self.log_func(record.name[-21:], msg, c)


class NetMap(object):
    def __init__(
        self,
        ips ,
        cidrs ,
        keep_lo=False,
        strict_cidr=False,
        defer_mutex=False,
    )  :
        """
        ips: list of plain ipv4/ipv6 IPs, not cidr
        cidrs: list of cidr-notation IPs (ip/prefix)
        """

        # fails multiprocessing; defer assignment
        self.mutex  = None if defer_mutex else threading.Lock()

        if "::" in ips:
            ips = [x for x in ips if x != "::"] + list(
                [x.split("/")[0] for x in cidrs if ":" in x]
            )
            ips.append("0.0.0.0")

        if "0.0.0.0" in ips:
            ips = [x for x in ips if x != "0.0.0.0"] + list(
                [x.split("/")[0] for x in cidrs if ":" not in x]
            )

        if not keep_lo:
            ips = [x for x in ips if x not in ("::1", "127.0.0.1")]

        ips = find_prefix(ips, cidrs)

        self.cache   = {}
        self.b2sip   = {}
        self.b2net    = {}
        self.bip  = []
        for ip in ips:
            v6 = ":" in ip
            fam = socket.AF_INET6 if v6 else socket.AF_INET
            bip = socket.inet_pton(fam, ip.split("/")[0])
            self.bip.append(bip)
            self.b2sip[bip] = ip.split("/")[0]
            self.b2net[bip] = (IPv6Network if v6 else IPv4Network)(ip, strict_cidr)

        self.bip.sort(reverse=True)

    def map(self, ip )  :
        if ip.startswith("::ffff:"):
            ip = ip[7:]

        try:
            return self.cache[ip]
        except:
            # intentionally crash the calling thread if unset:

            with self.mutex:
                return self._map(ip)

    def _map(self, ip )  :
        v6 = ":" in ip
        ci = IPv6Address(ip) if v6 else IPv4Address(ip)
        bip = next((x for x in self.bip if ci in self.b2net[x]), None)
        ret = self.b2sip[bip] if bip else ""
        if len(self.cache) > 9000:
            self.cache = {}
        self.cache[ip] = ret
        return ret


class UnrecvEOF(OSError):
    pass


class _Unrecv(object):
    """
    undo any number of socket recv ops
    """

    def __init__(self, s , log )  :
        self.s = s
        self.log = log
        self.buf  = b""

    def recv(self, nbytes , spins  = 1)  :
        if self.buf:
            ret = self.buf[:nbytes]
            self.buf = self.buf[nbytes:]
            return ret

        while True:
            try:
                ret = self.s.recv(nbytes)
                break
            except socket.timeout:
                spins -= 1
                if spins <= 0:
                    ret = b""
                    break
                continue
            except:
                ret = b""
                break

        if not ret:
            raise UnrecvEOF("client stopped sending data")

        return ret

    def recv_ex(self, nbytes , raise_on_trunc  = True)  :
        """read an exact number of bytes"""
        ret = b""
        try:
            while nbytes > len(ret):
                ret += self.recv(nbytes - len(ret))
        except OSError:
            t = "client stopped sending data; expected at least %d more bytes"
            if not ret:
                t = t % (nbytes,)
            else:
                t += ", only got %d"
                t = t % (nbytes, len(ret))
                if len(ret) <= 16:
                    t += "; %r" % (ret,)

            if raise_on_trunc:
                raise UnrecvEOF(5, t)
            elif self.log:
                self.log(t, 3)

        return ret

    def unrecv(self, buf )  :
        self.buf = buf + self.buf




Unrecv = _Unrecv


class CachedSet(object):
    def __init__(self, maxage )  :
        self.c   = {}
        self.maxage = maxage
        self.oldest = 0.0

    def add(self, v )  :
        self.c[v] = time.time()

    def cln(self)  :
        now = time.time()
        if now - self.oldest < self.maxage:
            return

        c = self.c = {k: v for k, v in self.c.items() if now - v < self.maxage}
        try:
            self.oldest = c[min(c, key=c.get)]  # type: ignore
        except:
            self.oldest = now


class CachedDict(object):
    def __init__(self, maxage )  :
        self.c    = {}
        self.maxage = maxage
        self.oldest = 0.0

    def set(self, k , v )  :
        now = time.time()
        self.c[k] = (now, v)
        if now - self.oldest < self.maxage:
            return

        c = self.c = {k: v for k, v in self.c.items() if now - v[0] < self.maxage}
        try:
            self.oldest = min([x[0] for x in c.values()])
        except:
            self.oldest = now

    def get(self, k )   :
        try:
            ts, ret = self.c[k]
            now = time.time()
            if now - ts > self.maxage:
                del self.c[k]
                return None
            return ret
        except:
            return None


class FHC(object):
    class CE(object):
        def __init__(self, fh )  :
            self.ts  = 0
            self.fhs = [fh]
            self.all_fhs = set([fh])

    def __init__(self)  :
        self.cache   = {}
        self.aps   = {}

    def close(self, path )  :
        try:
            ce = self.cache[path]
        except:
            return

        for fh in ce.fhs:
            fh.close()

        del self.cache[path]
        del self.aps[path]

    def clean(self)  :
        if not self.cache:
            return

        keep = {}
        now = time.time()
        for path, ce in self.cache.items():
            if now < ce.ts + 5:
                keep[path] = ce
            else:
                for fh in ce.fhs:
                    fh.close()

        self.cache = keep

    def pop(self, path )  :
        return self.cache[path].fhs.pop()

    def put(self, path , fh )  :
        if path not in self.aps:
            self.aps[path] = 0

        try:
            ce = self.cache[path]
            ce.all_fhs.add(fh)
            ce.fhs.append(fh)
        except:
            ce = self.CE(fh)
            self.cache[path] = ce

        ce.ts = time.time()


class ProgressPrinter(threading.Thread):
    """
    periodically print progress info without linefeeds
    """

    def __init__(self, log , args )  :
        threading.Thread.__init__(self, name="pp")
        self.daemon = True
        self.log = log
        self.args = args
        self.msg = ""
        self.end = False
        self.n = -1

    def run(self)  :
        sigblock()
        tp = 0
        msg = None
        no_stdout = self.args.q
        fmt = " {}\033[K\r" if VT100 else " {} $\r"
        while not self.end:
            time.sleep(0.1)
            if msg == self.msg or self.end:
                continue

            msg = self.msg
            now = time.time()
            if msg and now - tp > 10:
                tp = now
                self.log("progress: %r" % (msg,), 6)

            if no_stdout:
                continue

            uprint(fmt.format(msg))
            if PY2:
                sys.stdout.flush()

        if no_stdout:
            return

        if VT100:
            print("\033[K", end="")
        elif msg:
            print("------------------------")

        sys.stdout.flush()  # necessary on win10 even w/ stderr btw


class MTHash(object):
    def __init__(self, cores ):
        self.pp  = None
        self.f  = None
        self.sz = 0
        self.csz = 0
        self.stop = False
        self.readsz = 1024 * 1024 * (2 if (RAM_AVAIL or 2) < 1 else 12)
        self.omutex = threading.Lock()
        self.imutex = threading.Lock()
        self.work_q  = Queue()
        self.done_q     = Queue()
        self.thrs = []
        for n in range(cores):
            t = Daemon(self.worker, "mth-" + str(n))
            self.thrs.append(t)

    def hash(
        self,
        f ,
        fsz ,
        chunksz ,
        pp  = None,
        prefix  = "",
        suffix  = "",
    )    :
        with self.omutex:
            self.f = f
            self.sz = fsz
            self.csz = chunksz

            chunks     = {}
            nchunks = int(math.ceil(fsz / chunksz))
            for nch in range(nchunks):
                self.work_q.put(nch)

            ex = ""
            for nch in range(nchunks):
                qe = self.done_q.get()
                try:
                    nch, dig, ofs, csz = qe
                    chunks[nch] = (dig, ofs, csz)
                except:
                    ex = ex or str(qe)

                if pp:
                    mb = (fsz - nch * chunksz) // (1024 * 1024)
                    pp.msg = prefix + str(mb) + suffix

            if ex:
                raise Exception(ex)

            ret = []
            for n in range(nchunks):
                ret.append(chunks[n])

            self.f = None
            self.csz = 0
            self.sz = 0
            return ret

    def worker(self)  :
        while True:
            ofs = self.work_q.get()
            try:
                v = self.hash_at(ofs)
            except Exception as ex:
                v = str(ex)  # type: ignore

            self.done_q.put(v)

    def hash_at(self, nch )     :
        f = self.f
        ofs = ofs0 = nch * self.csz
        chunk_sz = chunk_rem = min(self.csz, self.sz - ofs)
        if self.stop:
            return nch, "", ofs0, chunk_sz

        hashobj = hashlib.sha512()
        while chunk_rem > 0:
            with self.imutex:
                f.seek(ofs)
                buf = f.read(min(chunk_rem, self.readsz))

            if not buf:
                raise Exception("EOF at " + str(ofs))

            hashobj.update(buf)
            chunk_rem -= len(buf)
            ofs += len(buf)

        bdig = hashobj.digest()[:33]
        udig = ub64enc(bdig).decode("ascii")
        return nch, udig, ofs0, chunk_sz


class HMaccas(object):
    def __init__(self, keypath , retlen )  :
        self.retlen = retlen
        self.cache   = {}
        try:
            with open(keypath, "rb") as f:
                self.key = f.read()
                if len(self.key) != 64:
                    raise Exception()
        except:
            self.key = os.urandom(64)
            with open(keypath, "wb") as f:
                f.write(self.key)

    def b(self, msg )  :
        try:
            return self.cache[msg]
        except:
            if len(self.cache) > 9000:
                self.cache = {}

            zb = hmac.new(self.key, msg, hashlib.sha512).digest()
            zs = ub64enc(zb)[: self.retlen].decode("ascii")
            self.cache[msg] = zs
            return zs

    def s(self, msg )  :
        return self.b(msg.encode("utf-8", "replace"))


class Magician(object):
    def __init__(self)  :
        self.bad_magic = False
        self.mutex = threading.Lock()
        self.magic  = None

    def ext(self, fpath )  :
        try:
            if self.bad_magic:
                raise Exception()

            if not self.magic:
                try:
                    with self.mutex:
                        if not self.magic:
                            self.magic = magic.Magic(uncompress=False, extension=True)
                except:
                    self.bad_magic = True
                    raise

            with self.mutex:
                ret = self.magic.from_file(fpath)
        except:
            ret = "?"

        ret = ret.split("/")[0]
        ret = MAGIC_MAP.get(ret, ret)
        if "?" not in ret:
            return ret

        mime = magic.from_file(fpath, mime=True)
        mime = re.split("[; ]", mime, maxsplit=1)[0]
        try:
            return EXTS[mime]
        except:
            pass

        mg = mimetypes.guess_extension(mime)
        if mg:
            return mg[1:]
        else:
            raise Exception()


class Garda(object):
    """ban clients for repeated offenses"""

    def __init__(self, cfg , uniq  = True)  :
        self.uniq = uniq
        try:
            a, b, c = cfg.strip().split(",")
            self.lim = int(a)
            self.win = int(b) * 60
            self.pen = int(c) * 60
        except:
            self.lim = self.win = self.pen = 0

        self.ct   = {}
        self.prev   = {}
        self.last_cln = 0

    def cln(self, ip )  :
        n = 0
        ok = int(time.time() - self.win)
        for v in self.ct[ip]:
            if v < ok:
                n += 1
            else:
                break
        if n:
            te = self.ct[ip][n:]
            if te:
                self.ct[ip] = te
            else:
                del self.ct[ip]
                try:
                    del self.prev[ip]
                except:
                    pass

    def allcln(self)  :
        for k in list(self.ct):
            self.cln(k)

        self.last_cln = int(time.time())

    def bonk(self, ip , prev )   :
        if not self.lim:
            return 0, ip

        if ":" in ip:
            # assume /64 clients; drop 4 groups
            ip = IPv6Address(ip).exploded[:-20]

        if prev and self.uniq:
            if self.prev.get(ip) == prev:
                return 0, ip

            self.prev[ip] = prev

        now = int(time.time())
        try:
            self.ct[ip].append(now)
        except:
            self.ct[ip] = [now]

        if now - self.last_cln > 300:
            self.allcln()
        else:
            self.cln(ip)

        if len(self.ct[ip]) >= self.lim:
            return now + self.pen, ip
        else:
            return 0, ip


if WINDOWS and sys.version_info < (3, 8):
    _popen = sp.Popen

    def _spopen(c, *a, **ka):
        enc = sys.getfilesystemencoding()
        c = [x.decode(enc, "replace") if hasattr(x, "decode") else x for x in c]
        return _popen(c, *a, **ka)

    sp.Popen = _spopen


def uprint(msg )  :
    try:
        print(msg, end="")
    except UnicodeEncodeError:
        try:
            print(msg.encode("utf-8", "replace").decode(), end="")
        except:
            print(msg.encode("ascii", "replace").decode(), end="")


def nuprint(msg )  :
    uprint("%s\n" % (msg,))


def dedent(txt )  :
    pad = 64
    lns = txt.replace("\r", "").split("\n")
    for ln in lns:
        zs = ln.lstrip()
        pad2 = len(ln) - len(zs)
        if zs and pad > pad2:
            pad = pad2
    return "\n".join([ln[pad:] for ln in lns])


def rice_tid()  :
    tid = threading.current_thread().ident
    c = sunpack(b"B" * 5, spack(b">Q", tid)[-5:])
    return "".join("\033[1;37;48;5;{0}m{0:02x}".format(x) for x in c) + "\033[0m"


def trace(*args , **kwargs )  :
    t = time.time()
    stack = "".join(
        "\033[36m%s\033[33m%s" % (x[0].split(os.sep)[-1][:-3], x[1])
        for x in traceback.extract_stack()[3:-1]
    )
    parts = ["%.6f" % (t,), rice_tid(), stack]

    if args:
        parts.append(repr(args))

    if kwargs:
        parts.append(repr(kwargs))

    msg = "\033[0m ".join(parts)
    # _tracebuf.append(msg)
    nuprint(msg)


def alltrace()  :
    threads   = {}
    names = dict([(t.ident, t.name) for t in threading.enumerate()])
    for tid, stack in sys._current_frames().items():
        name = "%s (%x)" % (names.get(tid), tid)
        threads[name] = stack

    rret  = []
    bret  = []
    for name, stack in sorted(threads.items()):
        ret = ["\n\n# %s" % (name,)]
        pad = None
        for fn, lno, name, line in traceback.extract_stack(stack):
            fn = os.sep.join(fn.split(os.sep)[-3:])
            ret.append('File: "%s", line %d, in %s' % (fn, lno, name))
            if line:
                ret.append("  " + str(line.strip()))
                if "self.not_empty.wait()" in line:
                    pad = " " * 4

        if pad:
            bret += [ret[0]] + [pad + x for x in ret[1:]]
        else:
            rret.extend(ret)

    return "\n".join(rret + bret) + "\n"


def start_stackmon(arg_str , nid )  :
    suffix = "-{}".format(nid) if nid else ""
    fp, f = arg_str.rsplit(",", 1)
    zi = int(f)
    Daemon(stackmon, "stackmon" + suffix, (fp, zi, suffix))


def stackmon(fp , ival , suffix )  :
    ctr = 0
    fp0 = fp
    while True:
        ctr += 1
        fp = fp0
        time.sleep(ival)
        st = "{}, {}\n{}".format(ctr, time.time(), alltrace())
        buf = st.encode("utf-8", "replace")

        if fp.endswith(".gz"):
            # 2459b 2304b 2241b 2202b 2194b 2191b lv3..8
            # 0.06s 0.08s 0.11s 0.13s 0.16s 0.19s
            buf = gzip.compress(buf, compresslevel=6)

        elif fp.endswith(".xz"):
            import lzma

            # 2276b 2216b 2200b 2192b 2168b lv0..4
            # 0.04s 0.10s 0.22s 0.41s 0.70s
            buf = lzma.compress(buf, preset=0)

        if "%" in fp:
            dt = datetime.now(UTC)
            for fs in "YmdHMS":
                fs = "%" + fs
                if fs in fp:
                    fp = fp.replace(fs, dt.strftime(fs))

        if "/" in fp:
            try:
                os.makedirs(fp.rsplit("/", 1)[0])
            except:
                pass

        with open(fp + suffix, "wb") as f:
            f.write(buf)


def start_log_thrs(
    logger    , ival , nid 
)  :
    ival = float(ival)
    tname = lname = "log-thrs"
    if nid:
        tname = "logthr-n{}-i{:x}".format(nid, os.getpid())
        lname = tname[3:]

    Daemon(log_thrs, tname, (logger, ival, lname))


def log_thrs(log    , ival , name )  :
    while True:
        time.sleep(ival)
        tv = [x.name for x in threading.enumerate()]
        tv = [
            x.split("-")[0]
            if x.split("-")[0] in ["httpconn", "thumb", "tagger"]
            else "listen"
            if "-listen-" in x
            else x
            for x in tv
            if not x.startswith("pydevd.")
        ]
        tv = ["{}\033[36m{}".format(v, k) for k, v in sorted(Counter(tv).items())]
        log(name, "\033[0m \033[33m".join(tv), 3)


def sigblock():
    if ANYWIN or PY2:
        return

    signal.pthread_sigmask(
        signal.SIG_BLOCK, [signal.SIGINT, signal.SIGTERM, signal.SIGUSR1]
    )


def vol_san(vols , txt )  :
    txt0 = txt
    for vol in vols:
        bap = vol.realpath.encode("utf-8")
        bhp = vol.histpath.encode("utf-8")
        bvp = vol.vpath.encode("utf-8")
        bvph = b"$hist(/" + bvp + b")"

        txt = txt.replace(bap, bvp)
        txt = txt.replace(bhp, bvph)
        txt = txt.replace(bap.replace(b"\\", b"\\\\"), bvp)
        txt = txt.replace(bhp.replace(b"\\", b"\\\\"), bvph)

        if vol.histpath != vol.dbpath:
            bdp = vol.dbpath.encode("utf-8")
            bdph = b"$db(/" + bvp + b")"
            txt = txt.replace(bdp, bdph)
            txt = txt.replace(bdp.replace(b"\\", b"\\\\"), bdph)

    if txt != txt0:
        txt += b"\r\nNOTE: filepaths sanitized; see serverlog for correct values"

    return txt


def min_ex(max_lines  = 8, reverse  = False)  :
    et, ev, tb = sys.exc_info()
    stb = traceback.extract_tb(tb) if tb else traceback.extract_stack()[:-1]
    fmt = "%s:%d <%s>: %s"
    ex = [fmt % (fp.split(os.sep)[-1], ln, fun, txt) for fp, ln, fun, txt in stb]
    if et or ev or tb:
        ex.append("[%s] %s" % (et.__name__ if et else "(anonymous)", ev))
    return "\n".join(ex[-max_lines:][:: -1 if reverse else 1])


def ren_open(fname , *args , **kwargs )   :
    fun = kwargs.pop("fun", open)
    fdir = kwargs.pop("fdir", None)
    suffix = kwargs.pop("suffix", None)

    if fname == os.devnull:
        return fun(fname, *args, **kwargs), fname

    if suffix:
        ext = fname.split(".")[-1]
        if len(ext) < 7:
            suffix += "." + ext

    orig_name = fname
    bname = fname
    ext = ""
    while True:
        ofs = bname.rfind(".")
        if ofs < 0 or ofs < len(bname) - 7:
            # doesn't look like an extension anymore
            break

        ext = bname[ofs:] + ext
        bname = bname[:ofs]

    asciified = False
    b64 = ""
    while True:
        f = None
        try:
            if fdir:
                fpath = os.path.join(fdir, fname)
            else:
                fpath = fname

            if suffix and os.path.lexists(fsenc(fpath)):
                fpath += suffix
                fname += suffix
                ext += suffix

            f = fun(fsenc(fpath), *args, **kwargs)
            if b64:
                fp2 = "fn-trunc.%s.txt" % (b64,)
                fp2 = os.path.join(fdir, fp2)
                with open(fsenc(fp2), "wb") as f2:
                    f2.write(orig_name.encode("utf-8"))

            return f, fname

        except OSError as ex_:
            ex = ex_
            if f:
                f.close()

            # EPERM: android13
            if ex.errno in (errno.EINVAL, errno.EPERM) and not asciified:
                asciified = True
                zsl = []
                for zs in (bname, fname):
                    zs = zs.encode("ascii", "replace").decode("ascii")
                    zs = re.sub(r"[^][a-zA-Z0-9(){}.,+=!-]", "_", zs)
                    zsl.append(zs)
                bname, fname = zsl
                continue

            # ENOTSUP: zfs on ubuntu 20.04
            if ex.errno not in (errno.ENAMETOOLONG, errno.ENOSR, errno.ENOTSUP) and (
                not WINDOWS or ex.errno != errno.EINVAL
            ):
                raise

        if not b64:
            zs = ("%s\n%s" % (orig_name, suffix)).encode("utf-8", "replace")
            b64 = ub64enc(hashlib.sha512(zs).digest()[:12]).decode("ascii")

        badlen = len(fname)
        while len(fname) >= badlen:
            if len(bname) < 8:
                raise ex

            if len(bname) > len(ext):
                # drop the last letter of the filename
                bname = bname[:-1]
            else:
                try:
                    # drop the leftmost sub-extension
                    _, ext = ext.split(".", 1)
                except:
                    # okay do the first letter then
                    ext = "." + ext[2:]

            fname = "%s~%s%s" % (bname, b64, ext)


class MultipartParser(object):
    def __init__(
        self,
        log_func ,
        args ,
        sr ,
        http_headers  ,
    ):
        self.sr = sr
        self.log = log_func
        self.args = args
        self.headers = http_headers

        self.re_ctype = re.compile(r"^content-type: *([^; ]+)", re.IGNORECASE)
        self.re_cdisp = re.compile(r"^content-disposition: *([^; ]+)", re.IGNORECASE)
        self.re_cdisp_field = re.compile(
            r'^content-disposition:(?: *|.*; *)name="([^"]+)"', re.IGNORECASE
        )
        self.re_cdisp_file = re.compile(
            r'^content-disposition:(?: *|.*; *)filename="(.*)"', re.IGNORECASE
        )

        self.boundary = b""
        self.gen                                                        = None





    def _read_header(self)   :
        """
        returns [fieldname, filename] after eating a block of multipart headers
        while doing a decent job at dealing with the absolute mess that is
        rfc1341/rfc1521/rfc2047/rfc2231/rfc2388/rfc6266/the-real-world
        (only the fallback non-js uploader relies on these filenames)
        """
        for ln in read_header(self.sr, 2, 2592000):
            self.log(repr(ln))

            m = self.re_ctype.match(ln)
            if m:
                if m.group(1).lower() == "multipart/mixed":
                    # rfc-7578 overrides rfc-2388 so this is not-impl
                    # (opera >=9 <11.10 is the only thing i've ever seen use it)
                    raise Pebkac(
                        400,
                        "you can't use that browser to upload multiple files at once",
                    )

                continue

            # the only other header we care about is content-disposition
            m = self.re_cdisp.match(ln)
            if not m:
                continue

            if m.group(1).lower() != "form-data":
                raise Pebkac(400, "not form-data: {}".format(ln))

            try:
                field = self.re_cdisp_field.match(ln).group(1)  # type: ignore
            except:
                raise Pebkac(400, "missing field name: {}".format(ln))

            try:
                fn = self.re_cdisp_file.match(ln).group(1)  # type: ignore
            except:
                # this is not a file upload, we're done
                return field, None

            try:
                is_webkit = "applewebkit" in self.headers["user-agent"].lower()
            except:
                is_webkit = False

            # chromes ignore the spec and makes this real easy
            if is_webkit:
                # quotes become %22 but they don't escape the %
                # so unescaping the quotes could turn messi
                return field, fn.split('"')[0]

            # also ez if filename doesn't contain "
            if not fn.split('"')[0].endswith("\\"):
                return field, fn.split('"')[0]

            # this breaks on firefox uploads that contain \"
            # since firefox escapes " but forgets to escape \
            # so it'll truncate after the \
            ret = ""
            esc = False
            for ch in fn:
                if esc:
                    esc = False
                    if ch not in ['"', "\\"]:
                        ret += "\\"
                    ret += ch
                elif ch == "\\":
                    esc = True
                elif ch == '"':
                    break
                else:
                    ret += ch

            return field, ret

        raise Pebkac(400, "server expected a multipart header but you never sent one")

    def _read_data(self)    :
        blen = len(self.boundary)
        bufsz = self.args.s_rd_sz
        while True:
            try:
                buf = self.sr.recv(bufsz)
            except:
                # abort: client disconnected
                raise Pebkac(400, "client d/c during multipart post")

            while True:
                ofs = buf.find(self.boundary)
                if ofs != -1:
                    self.sr.unrecv(buf[ofs + blen :])
                    yield buf[:ofs]
                    return

                d = len(buf) - blen
                if d > 0:
                    # buffer growing large; yield everything except
                    # the part at the end (maybe start of boundary)
                    yield buf[:d]
                    buf = buf[d:]

                # look for boundary near the end of the buffer
                n = 0
                for n in range(1, len(buf) + 1):
                    if not buf[-n:] in self.boundary:
                        n -= 1
                        break

                if n == 0 or not self.boundary.startswith(buf[-n:]):
                    # no boundary contents near the buffer edge
                    break

                if blen == n:
                    # EOF: found boundary
                    yield buf[:-n]
                    return

                try:
                    buf += self.sr.recv(bufsz)
                except:
                    # abort: client disconnected
                    raise Pebkac(400, "client d/c during multipart post")

            yield buf

    def _run_gen(
        self,
    )        :
        """
        yields [fieldname, unsanitized_filename, fieldvalue]
        where fieldvalue yields chunks of data
        """
        run = True
        while run:
            fieldname, filename = self._read_header()
            yield (fieldname, filename, self._read_data())

            tail = self.sr.recv_ex(2, False)

            if tail == b"--":
                # EOF indicated by this immediately after final boundary
                tail = self.sr.recv_ex(2, False)
                run = False

            if tail != b"\r\n":
                t = "protocol error after field value: want b'\\r\\n', got {!r}"
                raise Pebkac(400, t.format(tail))

    def _read_value(self, iterable , max_len )  :
        ret = b""
        for buf in iterable:
            ret += buf
            if len(ret) > max_len:
                raise Pebkac(422, "field length is too long")

        return ret

    def parse(self)  :
        boundary = get_boundary(self.headers)
        self.log("boundary=%r" % (boundary,))

        # spec says there might be junk before the first boundary,
        # can't have the leading \r\n if that's not the case
        self.boundary = b"--" + boundary.encode("utf-8")

        # discard junk before the first boundary
        for junk in self._read_data():
            if not junk:
                continue

            jtxt = junk.decode("utf-8", "replace")
            self.log("discarding preamble |%d| %r" % (len(junk), jtxt))

        # nice, now make it fast
        self.boundary = b"\r\n" + self.boundary
        self.gen = self._run_gen()

    def require(self, field_name , max_len )  :
        """
        returns the value of the next field in the multipart body,
        raises if the field name is not as expected
        """
        p_field, p_fname, p_data = next(self.gen)
        if p_field != field_name:
            raise WrongPostKey(field_name, p_field, p_fname, p_data)

        return self._read_value(p_data, max_len).decode("utf-8", "surrogateescape")

    def drop(self)  :
        """discards the remaining multipart body"""
        for _, _, data in self.gen:
            for _ in data:
                pass


def get_boundary(headers  )  :
    # boundaries contain a-z A-Z 0-9 ' ( ) + _ , - . / : = ?
    # (whitespace allowed except as the last char)
    ptn = r"^multipart/form-data *; *(.*; *)?boundary=([^;]+)"
    ct = headers["content-type"]
    m = re.match(ptn, ct, re.IGNORECASE)
    if not m:
        raise Pebkac(400, "invalid content-type for a multipart post: {}".format(ct))

    return m.group(2)


def read_header(sr , t_idle , t_tot )  :
    t0 = time.time()
    ret = b""
    while True:
        if time.time() - t0 >= t_tot:
            return []

        try:
            ret += sr.recv(1024, t_idle // 2)
        except:
            if not ret:
                return []

            raise Pebkac(
                400,
                "protocol error while reading headers",
                log=ret.decode("utf-8", "replace"),
            )

        ofs = ret.find(b"\r\n\r\n")
        if ofs < 0:
            if len(ret) > 1024 * 32:
                raise Pebkac(400, "header 2big")
            else:
                continue

        if len(ret) > ofs + 4:
            sr.unrecv(ret[ofs + 4 :])

        return ret[:ofs].decode("utf-8", "surrogateescape").lstrip("\r\n").split("\r\n")


def rand_name(fdir , fn , rnd )  :
    ok = False
    try:
        ext = "." + fn.rsplit(".", 1)[1]
    except:
        ext = ""

    for extra in range(16):
        for _ in range(16):
            if ok:
                break

            nc = rnd + extra
            nb = (6 + 6 * nc) // 8
            zb = ub64enc(os.urandom(nb))
            fn = zb[:nc].decode("ascii") + ext
            ok = not os.path.exists(fsenc(os.path.join(fdir, fn)))

    return fn


def gen_filekey(alg , salt , fspath , fsize , inode )  :
    if alg == 1:
        zs = "%s %s %s %s" % (salt, fspath, fsize, inode)
    else:
        zs = "%s %s" % (salt, fspath)

    zb = zs.encode("utf-8", "replace")
    return ub64enc(hashlib.sha512(zb).digest()).decode("ascii")


def gen_filekey_dbg(
    alg ,
    salt ,
    fspath ,
    fsize ,
    inode ,
    log ,
    log_ptn ,
)  :
    ret = gen_filekey(alg, salt, fspath, fsize, inode)

    if log_ptn.search(fspath):
        try:
            import inspect

            ctx = ",".join(inspect.stack()[n].function for n in range(2, 5))
        except:
            ctx = ""

        p2 = "a"
        try:
            p2 = absreal(fspath)
            if p2 != fspath:
                raise Exception()
        except:
            t = "maybe wrong abspath for filekey;\norig: %r\nreal: %r"
            log(t % (fspath, p2), 1)

        t = "fk(%s) salt(%s) size(%d) inode(%d) fspath(%r) at(%s)"
        log(t % (ret[:8], salt, fsize, inode, fspath, ctx), 5)

    return ret


WKDAYS = "Mon Tue Wed Thu Fri Sat Sun".split()
MONTHS = "Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec".split()
RFC2822 = "%s, %02d %s %04d %02d:%02d:%02d GMT"


def formatdate(ts  = None)  :
    # gmtime ~= datetime.fromtimestamp(ts, UTC).timetuple()
    y, mo, d, h, mi, s, wd, _, _ = time.gmtime(ts)
    return RFC2822 % (WKDAYS[wd], d, MONTHS[mo - 1], y, h, mi, s)


def gencookie(k , v , r , tls , dur  = 0, txt  = "")  :
    v = v.replace("%", "%25").replace(";", "%3B")
    if dur:
        exp = formatdate(time.time() + dur)
    else:
        exp = "Fri, 15 Aug 1997 01:00:00 GMT"

    t = "%s=%s; Path=/%s; Expires=%s%s%s; SameSite=Lax"
    return t % (k, v, r, exp, "; Secure" if tls else "", txt)


def humansize(sz , terse  = False)  :
    for unit in HUMANSIZE_UNITS:
        if sz < 1024:
            break

        sz /= 1024.0

    if terse:
        return "%s%s" % (str(sz)[:4].rstrip("."), unit[:1])
    else:
        return "%s %s" % (str(sz)[:4].rstrip("."), unit)


def unhumanize(sz )  :
    try:
        return int(sz)
    except:
        pass

    mc = sz[-1:].lower()
    mi = UNHUMANIZE_UNITS.get(mc, 1)
    return int(float(sz[:-1]) * mi)


def get_spd(nbyte , t0 , t  = None)  :
    if t is None:
        t = time.time()

    bps = nbyte / ((t - t0) or 0.001)
    s1 = humansize(nbyte).replace(" ", "\033[33m").replace("iB", "")
    s2 = humansize(bps).replace(" ", "\033[35m").replace("iB", "")
    return "%s \033[0m%s/s\033[0m" % (s1, s2)


def s2hms(s , optional_h  = False)  :
    s = int(s)
    h, s = divmod(s, 3600)
    m, s = divmod(s, 60)
    if not h and optional_h:
        return "%d:%02d" % (m, s)

    return "%d:%02d:%02d" % (h, m, s)


def djoin(*paths )  :
    """joins without adding a trailing slash on blank args"""
    return os.path.join(*[x for x in paths if x])


def uncyg(path )  :
    if len(path) < 2 or not path.startswith("/"):
        return path

    if len(path) > 2 and path[2] != "/":
        return path

    return "%s:\\%s" % (path[1], path[3:])


def undot(path )  :
    ret  = []
    for node in path.split("/"):
        if node == "." or not node:
            continue

        if node == "..":
            if ret:
                ret.pop()
            continue

        ret.append(node)

    return "/".join(ret)


def sanitize_fn(fn , ok )  :
    if "/" not in ok:
        fn = fn.replace("\\", "/").split("/")[-1]

    if ANYWIN:
        remap = [
            ["<", "＜"],
            [">", "＞"],
            [":", "："],
            ['"', "＂"],
            ["/", "／"],
            ["\\", "＼"],
            ["|", "｜"],
            ["?", "？"],
            ["*", "＊"],
        ]
        for a, b in [x for x in remap if x[0] not in ok]:
            fn = fn.replace(a, b)

        bad = ["con", "prn", "aux", "nul"]
        for n in range(1, 10):
            bad += ("com%s lpt%s" % (n, n)).split(" ")

        if fn.lower().split(".")[0] in bad:
            fn = "_" + fn

    return fn.strip()


def sanitize_vpath(vp , ok )  :
    parts = vp.replace(os.sep, "/").split("/")
    ret = [sanitize_fn(x, ok) for x in parts]
    return "/".join(ret)


def relchk(rp )  :
    if "\x00" in rp:
        return "[nul]"

    if ANYWIN:
        if "\n" in rp or "\r" in rp:
            return "x\nx"

        p = re.sub(r'[\\:*?"<>|]', "", rp)
        if p != rp:
            return "[{}]".format(p)

    return ""


def absreal(fpath )  :
    try:
        return fsdec(os.path.abspath(os.path.realpath(afsenc(fpath))))
    except:
        if not WINDOWS:
            raise

        # cpython bug introduced in 3.8, still exists in 3.9.1,
        # some win7sp1 and win10:20H2 boxes cannot realpath a
        # networked drive letter such as b"n:" or b"n:\\"
        return os.path.abspath(os.path.realpath(fpath))


def u8safe(txt )  :
    try:
        return txt.encode("utf-8", "xmlcharrefreplace").decode("utf-8", "replace")
    except:
        return txt.encode("utf-8", "replace").decode("utf-8", "replace")


def exclude_dotfiles(filepaths )  :
    return [x for x in filepaths if not x.split("/")[-1].startswith(".")]


def odfusion(
    base    , oth 
)   :
    # merge an "ordered set" (just a dict really) with another list of keys
    words0 = [x for x in oth.split(",") if x]
    words1 = [x for x in oth[1:].split(",") if x]

    ret = base.copy()
    if oth.startswith("+"):
        for k in words1:
            ret[k] = True
    elif oth[:1] in ("-", "/"):
        for k in words1:
            ret.pop(k, None)
    else:
        ret = ODict.fromkeys(words0, True)

    return ret


def ipnorm(ip )  :
    if ":" in ip:
        # assume /64 clients; drop 4 groups
        return IPv6Address(ip).exploded[:-20]

    return ip


def find_prefix(ips , cidrs )  :
    ret = []
    for ip in ips:
        hit = next((x for x in cidrs if x.startswith(ip + "/") or ip == x), None)
        if hit:
            ret.append(hit)
    return ret


def html_escape(s , quot  = False, crlf  = False)  :
    """html.escape but also newlines"""
    s = s.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
    if quot:
        s = s.replace('"', "&quot;").replace("'", "&#x27;")
    if crlf:
        s = s.replace("\r", "&#13;").replace("\n", "&#10;")

    return s


def html_bescape(s , quot  = False, crlf  = False)  :
    """html.escape but bytestrings"""
    s = s.replace(b"&", b"&amp;").replace(b"<", b"&lt;").replace(b">", b"&gt;")
    if quot:
        s = s.replace(b'"', b"&quot;").replace(b"'", b"&#x27;")
    if crlf:
        s = s.replace(b"\r", b"&#13;").replace(b"\n", b"&#10;")

    return s


def _quotep2(txt )  :
    """url quoter which deals with bytes correctly"""
    if not txt:
        return ""
    btxt = w8enc(txt)
    quot = quote(btxt, safe=b"/")
    return w8dec(quot.replace(b" ", b"+"))  # type: ignore


def _quotep3(txt )  :
    """url quoter which deals with bytes correctly"""
    if not txt:
        return ""
    btxt = w8enc(txt)
    quot = quote(btxt, safe=b"/").encode("utf-8")
    return w8dec(quot.replace(b" ", b"+"))


if not PY2:
    _uqsb = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_.-~/"
    _uqtl = {
        n: ("%%%02X" % (n,) if n not in _uqsb else chr(n)).encode("utf-8")
        for n in range(256)
    }
    _uqtl[b" "] = b"+"

    def _quotep3b(txt )  :
        """url quoter which deals with bytes correctly"""
        if not txt:
            return ""
        btxt = w8enc(txt)
        if btxt.rstrip(_uqsb):
            lut = _uqtl
            btxt = b"".join([lut[ch] for ch in btxt])
        return w8dec(btxt)

    quotep = _quotep3b

    _hexd = "0123456789ABCDEFabcdef"
    _hex2b = {(a + b).encode(): bytes.fromhex(a + b) for a in _hexd for b in _hexd}

    def unquote(btxt )  :
        h2b = _hex2b
        parts = iter(btxt.split(b"%"))
        ret = [next(parts)]
        for item in parts:
            c = h2b.get(item[:2])
            if c is None:
                ret.append(b"%")
                ret.append(item)
            else:
                ret.append(c)
                ret.append(item[2:])
        return b"".join(ret)

    from urllib.parse import quote_from_bytes as quote
else:
    from urllib import quote  # type: ignore # pylint: disable=no-name-in-module
    from urllib import unquote  # type: ignore # pylint: disable=no-name-in-module

    quotep = _quotep2


def unquotep(txt )  :
    """url unquoter which deals with bytes correctly"""
    btxt = w8enc(txt)
    unq2 = unquote(btxt)
    return w8dec(unq2)


def vroots(vp1 , vp2 )   :
    """
    input("q/w/e/r","a/s/d/e/r") output("/q/w/","/a/s/d/")
    """
    while vp1 and vp2:
        zt1 = vp1.rsplit("/", 1) if "/" in vp1 else ("", vp1)
        zt2 = vp2.rsplit("/", 1) if "/" in vp2 else ("", vp2)
        if zt1[1] != zt2[1]:
            break
        vp1 = zt1[0]
        vp2 = zt2[0]
    return (
        "/%s/" % (vp1,) if vp1 else "/",
        "/%s/" % (vp2,) if vp2 else "/",
    )


def vsplit(vpath )   :
    if "/" not in vpath:
        return "", vpath

    return vpath.rsplit("/", 1)  # type: ignore


# vpath-join
def vjoin(rd , fn )  :
    if rd and fn:
        return rd + "/" + fn
    else:
        return rd or fn


# url-join
def ujoin(rd , fn )  :
    if rd and fn:
        return rd.rstrip("/") + "/" + fn.lstrip("/")
    else:
        return rd or fn


def log_reloc(
    log ,
    re  ,
    pm     ,
    ap ,
    vp ,
    fn ,
    vn ,
    rem ,
)  :
    nap, nvp, nfn, (nvn, nrem) = pm
    t = "reloc %s:\nold ap %r\nnew ap %r\033[36m/%r\033[0m\nold vp %r\nnew vp %r\033[36m/%r\033[0m\nold fn %r\nnew fn %r\nold vfs %r\nnew vfs %r\nold rem %r\nnew rem %r"
    log(t % (re, ap, nap, nfn, vp, nvp, nfn, fn, nfn, vn.vpath, nvn.vpath, rem, nrem))


def pathmod(
    vfs , ap , vp , mod  
)      :
    # vfs: authsrv.vfs
    # ap: original abspath to a file
    # vp: original urlpath to a file
    # mod: modification (ap/vp/fn)

    nvp = "\n"  # new vpath
    ap = os.path.dirname(ap)
    vp, fn = vsplit(vp)
    if mod.get("fn"):
        fn = mod["fn"]
        nvp = vp

    for ref, k in ((ap, "ap"), (vp, "vp")):
        if k not in mod:
            continue

        ms = mod[k].replace(os.sep, "/")
        if ms.startswith("/"):
            np = ms
        elif k == "vp":
            np = undot(vjoin(ref, ms))
        else:
            np = os.path.abspath(os.path.join(ref, ms))

        if k == "vp":
            nvp = np.lstrip("/")
            continue

        # try to map abspath to vpath
        np = np.replace("/", os.sep)
        for vn_ap, vn in vfs.all_aps:
            if not np.startswith(vn_ap):
                continue
            zs = np[len(vn_ap) :].replace(os.sep, "/")
            nvp = vjoin(vn.vpath, zs)
            break

    if nvp == "\n":
        return None

    vn, rem = vfs.get(nvp, "*", False, False)
    if not vn.realpath:
        raise Exception("unmapped vfs")

    ap = vn.canonical(rem)
    return ap, nvp, fn, (vn, rem)


def _w8dec2(txt )  :
    """decodes filesystem-bytes to wtf8"""
    return surrogateescape.decodefilename(txt)


def _w8enc2(txt )  :
    """encodes wtf8 to filesystem-bytes"""
    return surrogateescape.encodefilename(txt)


def _w8dec3(txt )  :
    """decodes filesystem-bytes to wtf8"""
    return txt.decode(FS_ENCODING, "surrogateescape")


def _w8enc3(txt )  :
    """encodes wtf8 to filesystem-bytes"""
    return txt.encode(FS_ENCODING, "surrogateescape")


def _msdec(txt )  :
    ret = txt.decode(FS_ENCODING, "surrogateescape")
    return ret[4:] if ret.startswith("\\\\?\\") else ret


def _msaenc(txt )  :
    return txt.replace("/", "\\").encode(FS_ENCODING, "surrogateescape")


def _uncify(txt )  :
    txt = txt.replace("/", "\\")
    if ":" not in txt and not txt.startswith("\\\\"):
        txt = absreal(txt)

    return txt if txt.startswith("\\\\") else "\\\\?\\" + txt


def _msenc(txt )  :
    txt = txt.replace("/", "\\")
    if ":" not in txt and not txt.startswith("\\\\"):
        txt = absreal(txt)

    ret = txt.encode(FS_ENCODING, "surrogateescape")
    return ret if ret.startswith(b"\\\\") else b"\\\\?\\" + ret


w8dec = _w8dec3 if not PY2 else _w8dec2
w8enc = _w8enc3 if not PY2 else _w8enc2


def w8b64dec(txt )  :
    """decodes base64(filesystem-bytes) to wtf8"""
    return w8dec(ub64dec(txt.encode("ascii")))


def w8b64enc(txt )  :
    """encodes wtf8 to base64(filesystem-bytes)"""
    return ub64enc(w8enc(txt)).decode("ascii")


if not PY2 and WINDOWS:
    sfsenc = w8enc
    afsenc = _msaenc
    fsenc = _msenc
    fsdec = _msdec
    uncify = _uncify
elif not PY2 or not WINDOWS:
    fsenc = afsenc = sfsenc = w8enc
    fsdec = w8dec
    uncify = str
else:
    # moonrunes become \x3f with bytestrings,
    # losing mojibake support is worth
    def _not_actually_mbcs_enc(txt )  :
        return txt  # type: ignore

    def _not_actually_mbcs_dec(txt )  :
        return txt  # type: ignore

    fsenc = afsenc = sfsenc = _not_actually_mbcs_enc
    fsdec = _not_actually_mbcs_dec
    uncify = str


def s3enc(mem_cur , rd , fn )   :
    ret  = []
    for v in [rd, fn]:
        try:
            mem_cur.execute("select * from a where b = ?", (v,))
            ret.append(v)
        except:
            ret.append("//" + w8b64enc(v))
            # self.log("mojien [{}] {}".format(v, ret[-1][2:]))

    return ret[0], ret[1]


def s3dec(rd , fn )   :
    return (
        w8b64dec(rd[2:]) if rd.startswith("//") else rd,
        w8b64dec(fn[2:]) if fn.startswith("//") else fn,
    )


def db_ex_chk(log , ex , db_path )  :
    if str(ex) != "database is locked":
        return False

    Daemon(lsof, "dbex", (log, db_path))
    return True


def lsof(log , abspath )  :
    try:
        rc, so, se = runcmd([b"lsof", b"-R", fsenc(abspath)], timeout=45)
        zs = (so.strip() + "\n" + se.strip()).strip()
        log("lsof %r = %s\n%s" % (abspath, rc, zs), 3)
    except:
        log("lsof failed; " + min_ex(), 3)


def _fs_mvrm(
    log , src , dst , atomic , flags  
)  :
    bsrc = fsenc(src)
    bdst = fsenc(dst)
    if atomic:
        k = "mv_re_"
        act = "atomic-rename"
        osfun = os.replace
        args = [bsrc, bdst]
    elif dst:
        k = "mv_re_"
        act = "rename"
        osfun = os.rename
        args = [bsrc, bdst]
    else:
        k = "rm_re_"
        act = "delete"
        osfun = os.unlink
        args = [bsrc]

    maxtime = flags.get(k + "t", 0.0)
    chill = flags.get(k + "r", 0.0)
    if chill < 0.001:
        chill = 0.1

    ino = 0
    t0 = now = time.time()
    for attempt in range(90210):
        try:
            if ino and os.stat(bsrc).st_ino != ino:
                t = "src inode changed; aborting %s %r"
                log(t % (act, src), 1)
                return False
            if (dst and not atomic) and os.path.exists(bdst):
                t = "something appeared at dst; aborting rename %r ==> %r"
                log(t % (src, dst), 1)
                return False
            osfun(*args)
            if attempt:
                now = time.time()
                t = "%sd in %.2f sec, attempt %d: %r"
                log(t % (act, now - t0, attempt + 1, src))
            return True
        except OSError as ex:
            now = time.time()
            if ex.errno == errno.ENOENT:
                return False
            if not attempt and ex.errno == errno.EXDEV:
                t = "using copy+delete (%s)\n  %s\n  %s"
                log(t % (ex.strerror, src, dst))
                osfun = shutil.move
                continue
            if now - t0 > maxtime or attempt == 90209:
                raise
            if not attempt:
                if not PY2:
                    ino = os.stat(bsrc).st_ino
                t = "%s failed (err.%d); retrying for %d sec: %r"
                log(t % (act, ex.errno, maxtime + 0.99, src))

        time.sleep(chill)

    return False  # makes pylance happy


def atomic_move(log , src , dst , flags  )  :
    bsrc = fsenc(src)
    bdst = fsenc(dst)
    if PY2:
        if os.path.exists(bdst):
            _fs_mvrm(log, dst, "", False, flags)  # unlink

        _fs_mvrm(log, src, dst, False, flags)  # rename
    elif flags.get("mv_re_t"):
        _fs_mvrm(log, src, dst, True, flags)
    else:
        try:
            os.replace(bsrc, bdst)
        except OSError as ex:
            if ex.errno != errno.EXDEV:
                raise
            t = "using copy+delete (%s);\n  %s\n  %s"
            log(t % (ex.strerror, src, dst))
            try:
                os.unlink(bdst)
            except:
                pass
            shutil.move(bsrc, bdst)


def wunlink(log , abspath , flags  )  :
    if not flags.get("rm_re_t"):
        os.unlink(fsenc(abspath))
        return True

    return _fs_mvrm(log, abspath, "", False, flags)


def get_df(abspath , prune )    :
    try:
        ap = fsenc(abspath)
        while prune and not os.path.isdir(ap) and BOS_SEP in ap:
            # strip leafs until it hits an existing folder
            ap = ap.rsplit(BOS_SEP, 1)[0]

        if ANYWIN:
            abspath = fsdec(ap)
            bfree = ctypes.c_ulonglong(0)
            ctypes.windll.kernel32.GetDiskFreeSpaceExW(  # type: ignore
                ctypes.c_wchar_p(abspath), None, None, ctypes.pointer(bfree)
            )
            return (bfree.value, None, "")
        else:
            sv = os.statvfs(ap)
            free = sv.f_frsize * sv.f_bfree
            total = sv.f_frsize * sv.f_blocks
            return (free, total, "")
    except Exception as ex:
        return (None, None, repr(ex))


if not ANYWIN and not MACOS:

    def siocoutq(sck )  :
        # SIOCOUTQ^sockios.h == TIOCOUTQ^ioctl.h
        try:
            zb = fcntl.ioctl(sck.fileno(), termios.TIOCOUTQ, b"AAAA")
            return sunpack(b"I", zb)[0]  # type: ignore
        except:
            return 1

else:
    # macos: getsockopt(fd, SOL_SOCKET, SO_NWRITE, ...)
    # windows: TcpConnectionEstatsSendBuff

    def siocoutq(sck )  :
        return 1


def shut_socket(log , sck , timeout  = 3)  :
    t0 = time.time()
    fd = sck.fileno()
    if fd == -1:
        sck.close()
        return

    try:
        sck.settimeout(timeout)
        sck.shutdown(socket.SHUT_WR)
        try:
            while time.time() - t0 < timeout:
                if not siocoutq(sck):
                    # kernel says tx queue empty, we good
                    break

                # on windows in particular, drain rx until client shuts
                if not sck.recv(32 * 1024):
                    break

            sck.shutdown(socket.SHUT_RDWR)
        except:
            pass
    except Exception as ex:
        log("shut({}): {}".format(fd, ex), "90")
    finally:
        td = time.time() - t0
        if td >= 1:
            log("shut({}) in {:.3f} sec".format(fd, td), "90")

        sck.close()


def read_socket(
    sr , bufsz , total_size 
)    :
    remains = total_size
    while remains > 0:
        if bufsz > remains:
            bufsz = remains

        try:
            buf = sr.recv(bufsz)
        except OSError:
            t = "client d/c during binary post after {} bytes, {} bytes remaining"
            raise Pebkac(400, t.format(total_size - remains, remains))

        remains -= len(buf)
        yield buf


def read_socket_unbounded(sr , bufsz )    :
    try:
        while True:
            yield sr.recv(bufsz)
    except:
        return


def read_socket_chunked(
    sr , bufsz , log  = None
)    :
    err = "upload aborted: expected chunk length, got [{}] |{}| instead"
    while True:
        buf = b""
        while b"\r" not in buf:
            try:
                buf += sr.recv(2)
                if len(buf) > 16:
                    raise Exception()
            except:
                err = err.format(buf.decode("utf-8", "replace"), len(buf))
                raise Pebkac(400, err)

        if not buf.endswith(b"\n"):
            sr.recv(1)

        try:
            chunklen = int(buf.rstrip(b"\r\n"), 16)
        except:
            err = err.format(buf.decode("utf-8", "replace"), len(buf))
            raise Pebkac(400, err)

        if chunklen == 0:
            x = sr.recv_ex(2, False)
            if x == b"\r\n":
                return

            t = "protocol error after final chunk: want b'\\r\\n', got {!r}"
            raise Pebkac(400, t.format(x))

        if log:
            log("receiving %d byte chunk" % (chunklen,))

        for chunk in read_socket(sr, bufsz, chunklen):
            yield chunk

        x = sr.recv_ex(2, False)
        if x != b"\r\n":
            t = "protocol error in chunk separator: want b'\\r\\n', got {!r}"
            raise Pebkac(400, t.format(x))


def list_ips()  :
    from .stolen.ifaddr import get_adapters

    ret  = set()
    for nic in get_adapters():
        for ipo in nic.ips:
            if len(ipo.ip) < 7:
                ret.add(ipo.ip[0])  # ipv6 is (ip,0,0)
            else:
                ret.add(ipo.ip)

    return list(ret)


def build_netmap(csv , defer_mutex  = False):
    csv = csv.lower().strip()

    if csv in ("any", "all", "no", ",", ""):
        return None

    srcs = [x.strip() for x in csv.split(",") if x.strip()]

    expanded_shorthands = False
    for shorthand in ("lan", "local", "private", "prvt"):
        if shorthand in srcs:
            if not expanded_shorthands:
                srcs += [
                    # lan:
                    "10.0.0.0/8",
                    "172.16.0.0/12",
                    "192.168.0.0/16",
                    "fd00::/8",
                    # link-local:
                    "169.254.0.0/16",
                    "fe80::/10",
                    # loopback:
                    "127.0.0.0/8",
                    "::1/128",
                ]
                expanded_shorthands = True

            srcs.remove(shorthand)

    if not HAVE_IPV6:
        srcs = [x for x in srcs if ":" not in x]

    cidrs = []
    for zs in srcs:
        if not zs.endswith("."):
            cidrs.append(zs)
            continue

        # translate old syntax "172.19." => "172.19.0.0/16"
        words = len(zs.rstrip(".").split("."))
        if words == 1:
            zs += "0.0.0/8"
        elif words == 2:
            zs += "0.0/16"
        elif words == 3:
            zs += "0/24"
        else:
            raise Exception("invalid config value [%s]" % (zs,))

        cidrs.append(zs)

    ips = [x.split("/")[0] for x in cidrs]
    return NetMap(ips, cidrs, True, False, defer_mutex)


def load_ipu(
    log , ipus , defer_mutex  = False
)    :
    ip_u = {"": "*"}
    cidr_u = {}
    for ipu in ipus:
        try:
            cidr, uname = ipu.split("=")
            cip, csz = cidr.split("/")
        except:
            t = "\n  invalid value %r for argument --ipu; must be CIDR=UNAME (192.168.0.0/16=amelia)"
            raise Exception(t % (ipu,))
        uname2 = cidr_u.get(cidr)
        if uname2 is not None:
            t = "\n  invalid value %r for argument --ipu; cidr %s already mapped to %r"
            raise Exception(t % (ipu, cidr, uname2))
        cidr_u[cidr] = uname
        ip_u[cip] = uname
    try:
        nm = NetMap(["::"], list(cidr_u.keys()), True, True, defer_mutex)
    except Exception as ex:
        t = "failed to translate --ipu into netmap, probably due to invalid config: %r"
        log("root", t % (ex,), 1)
        raise
    return ip_u, nm


def yieldfile(fn , bufsz )    :
    readsz = min(bufsz, 128 * 1024)
    with open(fsenc(fn), "rb", bufsz) as f:
        while True:
            buf = f.read(readsz)
            if not buf:
                break

            yield buf


def justcopy(
    fin   ,
    fout  ,
    hashobj ,
    max_sz ,
    slp ,
)    :
    tlen = 0
    for buf in fin:
        tlen += len(buf)
        if max_sz and tlen > max_sz:
            continue

        fout.write(buf)
        if slp:
            time.sleep(slp)

    return tlen, "checksum-disabled", "checksum-disabled"


def hashcopy(
    fin   ,
    fout  ,
    hashobj ,
    max_sz ,
    slp ,
)    :
    if not hashobj:
        hashobj = hashlib.sha512()
    tlen = 0
    for buf in fin:
        tlen += len(buf)
        if max_sz and tlen > max_sz:
            continue

        hashobj.update(buf)
        fout.write(buf)
        if slp:
            time.sleep(slp)

    digest_b64 = ub64enc(hashobj.digest()[:33]).decode("ascii")

    return tlen, hashobj.hexdigest(), digest_b64


def sendfile_py(
    log ,
    lower ,
    upper ,
    f ,
    s ,
    bufsz ,
    slp ,
    use_poll ,
    dls   ,
    dl_id ,
)  :
    sent = 0
    remains = upper - lower
    f.seek(lower)
    while remains > 0:
        if slp:
            time.sleep(slp)

        buf = f.read(min(bufsz, remains))
        if not buf:
            return remains

        try:
            s.sendall(buf)
            remains -= len(buf)
        except:
            return remains

        if dl_id:
            sent += len(buf)
            dls[dl_id] = (time.time(), sent)

    return 0


def sendfile_kern(
    log ,
    lower ,
    upper ,
    f ,
    s ,
    bufsz ,
    slp ,
    use_poll ,
    dls   ,
    dl_id ,
)  :
    out_fd = s.fileno()
    in_fd = f.fileno()
    ofs = lower
    stuck = 0.0
    if use_poll:
        poll = select.poll()
        poll.register(out_fd, select.POLLOUT)

    while ofs < upper:
        stuck = stuck or time.time()
        try:
            req = min(0x2000000, upper - ofs)  # 32 MiB
            if use_poll:
                poll.poll(10000)
            else:
                select.select([], [out_fd], [], 10)
            n = os.sendfile(out_fd, in_fd, ofs, req)
            stuck = 0
        except OSError as ex:
            # client stopped reading; do another select
            d = time.time() - stuck
            if d < 3600 and ex.errno == errno.EWOULDBLOCK:
                time.sleep(0.02)
                continue

            n = 0
        except Exception as ex:
            n = 0
            d = time.time() - stuck
            log("sendfile failed after {:.3f} sec: {!r}".format(d, ex))

        if n <= 0:
            return upper - ofs

        ofs += n
        if dl_id:
            dls[dl_id] = (time.time(), ofs - lower)

        # print("sendfile: ok, sent {} now, {} total, {} remains".format(n, ofs - lower, upper - ofs))

    return 0


def statdir(
    logger , scandir , lstat , top , throw 
)     :
    if lstat and ANYWIN:
        lstat = False

    if lstat and (PY2 or os.stat not in os.supports_follow_symlinks):
        scandir = False

    src = "statdir"
    try:
        btop = fsenc(top)
        if scandir and hasattr(os, "scandir"):
            src = "scandir"
            with os.scandir(btop) as dh:
                for fh in dh:
                    try:
                        yield (fsdec(fh.name), fh.stat(follow_symlinks=not lstat))
                    except Exception as ex:
                        if not logger:
                            continue

                        logger(src, "[s] {} @ {}".format(repr(ex), fsdec(fh.path)), 6)
        else:
            src = "listdir"
            fun  = os.lstat if lstat else os.stat
            for name in os.listdir(btop):
                abspath = os.path.join(btop, name)
                try:
                    yield (fsdec(name), fun(abspath))
                except Exception as ex:
                    if not logger:
                        continue

                    logger(src, "[s] {} @ {}".format(repr(ex), fsdec(abspath)), 6)

    except Exception as ex:
        if throw:
            zi = getattr(ex, "errno", 0)
            if zi == errno.ENOENT:
                raise Pebkac(404, str(ex))
            raise

        t = "{} @ {}".format(repr(ex), top)
        if logger:
            logger(src, t, 1)
        else:
            print(t)


def dir_is_empty(logger , scandir , top ):
    for _ in statdir(logger, scandir, False, top, False):
        return False
    return True


def rmdirs(
    logger , scandir , lstat , top , depth 
)   :
    """rmdir all descendants, then self"""
    if not os.path.isdir(fsenc(top)):
        top = os.path.dirname(top)
        depth -= 1

    stats = statdir(logger, scandir, lstat, top, False)
    dirs = [x[0] for x in stats if stat.S_ISDIR(x[1].st_mode)]
    dirs = [os.path.join(top, x) for x in dirs]
    ok = []
    ng = []
    for d in reversed(dirs):
        a, b = rmdirs(logger, scandir, lstat, d, depth + 1)
        ok += a
        ng += b

    if depth:
        try:
            os.rmdir(fsenc(top))
            ok.append(top)
        except:
            ng.append(top)

    return ok, ng


def rmdirs_up(top , stop )   :
    """rmdir on self, then all parents"""
    if top == stop:
        return [], [top]

    try:
        os.rmdir(fsenc(top))
    except:
        return [], [top]

    par = os.path.dirname(top)
    if not par or par == stop:
        return [top], []

    ok, ng = rmdirs_up(par, stop)
    return [top] + ok, ng


def unescape_cookie(orig )  :
    # mw=idk; doot=qwe%2Crty%3Basd+fgh%2Bjkl%25zxc%26vbn  # qwe,rty;asd fgh+jkl%zxc&vbn
    ret = []
    esc = ""
    for ch in orig:
        if ch == "%":
            if esc:
                ret.append(esc)
            esc = ch

        elif esc:
            esc += ch
            if len(esc) == 3:
                try:
                    ret.append(chr(int(esc[1:], 16)))
                except:
                    ret.append(esc)
                esc = ""

        else:
            ret.append(ch)

    if esc:
        ret.append(esc)

    return "".join(ret)


def guess_mime(
    url , path  = "", fallback  = "application/octet-stream"
)  :
    try:
        ext = url.rsplit(".", 1)[1].lower()
    except:
        ext = ""

    ret = MIMES.get(ext)

    if not ret:
        x = mimetypes.guess_type(url)
        ret = "application/{}".format(x[1]) if x[1] else x[0]

    if not ret and path:
        try:
            with open(fsenc(path), "rb", 0) as f:
                ret = magic.from_buffer(f.read(4096), mime=True)
                if ret.startswith("text/htm"):
                    # avoid serving up HTML content unless there was actually a .html extension
                    ret = "text/plain"
        except Exception as ex:
            pass

    if not ret:
        ret = fallback

    if ";" not in ret:
        if ret.startswith("text/") or ret.endswith("/javascript"):
            ret += "; charset=utf-8"

    return ret


def getalive(pids , pgid )  :
    alive = []
    for pid in pids:
        try:
            if pgid:
                # check if still one of ours
                if os.getpgid(pid) == pgid:
                    alive.append(pid)
            else:
                # windows doesn't have pgroups; assume
                psutil.Process(pid)
                alive.append(pid)
        except:
            pass

    return alive


def killtree(root )  :
    """still racy but i tried"""
    try:
        # limit the damage where possible (unixes)
        pgid = os.getpgid(os.getpid())
    except:
        pgid = 0

    if HAVE_PSUTIL:
        pids = [root]
        parent = psutil.Process(root)
        for child in parent.children(recursive=True):
            pids.append(child.pid)
            child.terminate()
        parent.terminate()
        parent = None
    elif pgid:
        # linux-only
        pids = []
        chk = [root]
        while chk:
            pid = chk[0]
            chk = chk[1:]
            pids.append(pid)
            _, t, _ = runcmd(["pgrep", "-P", str(pid)])
            chk += [int(x) for x in t.strip().split("\n") if x]

        pids = getalive(pids, pgid)  # filter to our pgroup
        for pid in pids:
            os.kill(pid, signal.SIGTERM)
    else:
        # windows gets minimal effort sorry
        os.kill(root, signal.SIGTERM)
        return

    for n in range(10):
        time.sleep(0.1)
        pids = getalive(pids, pgid)
        if not pids or n > 3 and pids == [root]:
            break

    for pid in pids:
        try:
            os.kill(pid, signal.SIGKILL)
        except:
            pass


def _find_nice()  :
    if WINDOWS:
        return ""  # use creationflags

    try:
        zs = shutil.which("nice")
        if zs:
            return zs
    except:
        pass

    # busted PATHs and/or py2
    for zs in ("/bin", "/sbin", "/usr/bin", "/usr/sbin"):
        zs += "/nice"
        if os.path.exists(zs):
            return zs

    return ""


NICES = _find_nice()
NICEB = NICES.encode("utf-8")


def runcmd(
    argv  , timeout  = None, **ka 
)    :
    isbytes = isinstance(argv[0], (bytes, bytearray))
    oom = ka.pop("oom", 0)  # 0..1000
    kill = ka.pop("kill", "t")  # [t]ree [m]ain [n]one
    capture = ka.pop("capture", 3)  # 0=none 1=stdout 2=stderr 3=both

    sin  = ka.pop("sin", None)
    if sin:
        ka["stdin"] = sp.PIPE

    cout = sp.PIPE if capture in [1, 3] else None
    cerr = sp.PIPE if capture in [2, 3] else None
    #bout: bytes
    #berr: bytes

    if ANYWIN:
        if isbytes:
            if argv[0] in CMD_EXEB:
                argv[0] += b".exe"
        else:
            if argv[0] in CMD_EXES:
                argv[0] += ".exe"

    if ka.pop("nice", None):
        if WINDOWS:
            ka["creationflags"] = 0x4000
        elif NICEB:
            if isbytes:
                argv = [NICEB] + argv
            else:
                argv = [NICES] + argv

    p = sp.Popen(argv, stdout=cout, stderr=cerr, **ka)

    if oom and not ANYWIN and not MACOS:
        try:
            with open("/proc/%d/oom_score_adj" % (p.pid,), "wb") as f:
                f.write(("%d\n" % (oom,)).encode("utf-8"))
        except:
            pass

    if not timeout or PY2:
        bout, berr = p.communicate(sin)
    else:
        try:
            bout, berr = p.communicate(sin, timeout=timeout)
        except sp.TimeoutExpired:
            if kill == "n":
                return -18, "", ""  # SIGCONT; leave it be
            elif kill == "m":
                p.kill()
            else:
                killtree(p.pid)

            try:
                bout, berr = p.communicate(timeout=1)
            except:
                bout = b""
                berr = b""

    stdout = bout.decode("utf-8", "replace") if cout else ""
    stderr = berr.decode("utf-8", "replace") if cerr else ""

    rc  = p.returncode
    if rc is None:
        rc = -14  # SIGALRM; failed to kill

    return rc, stdout, stderr


def chkcmd(argv  , **ka )   :
    ok, sout, serr = runcmd(argv, **ka)
    if ok != 0:
        retchk(ok, argv, serr)
        raise Exception(serr)

    return sout, serr


def mchkcmd(argv  , timeout  = 10)  :
    if PY2:
        with open(os.devnull, "wb") as f:
            rv = sp.call(argv, stdout=f, stderr=f)
    else:
        rv = sp.call(argv, stdout=sp.DEVNULL, stderr=sp.DEVNULL, timeout=timeout)

    if rv:
        raise sp.CalledProcessError(rv, (argv[0], b"...", argv[-1]))


def retchk(
    rc ,
    cmd  ,
    serr ,
    logger  = None,
    color   = 0,
    verbose  = False,
)  :
    if rc < 0:
        rc = 128 - rc

    if not rc or rc < 126 and not verbose:
        return

    s = None
    if rc > 128:
        try:
            s = str(signal.Signals(rc - 128))
        except:
            pass
    elif rc == 126:
        s = "invalid program"
    elif rc == 127:
        s = "program not found"
    elif verbose:
        s = "unknown"
    else:
        s = "invalid retcode"

    if s:
        t = "{} <{}>".format(rc, s)
    else:
        t = str(rc)

    try:
        c = " ".join([fsdec(x) for x in cmd])  # type: ignore
    except:
        c = str(cmd)

    t = "error {} from [{}]".format(t, c)
    if serr:
        t += "\n" + serr

    if logger:
        logger(t, color)
    else:
        raise Exception(t)


def _parsehook(
    log , cmd 
)         :
    areq = ""
    chk = False
    fork = False
    jtxt = False
    wait = 0.0
    tout = 0.0
    kill = "t"
    cap = 0
    ocmd = cmd
    while "," in cmd[:6]:
        arg, cmd = cmd.split(",", 1)
        if arg == "c":
            chk = True
        elif arg == "f":
            fork = True
        elif arg == "j":
            jtxt = True
        elif arg.startswith("w"):
            wait = float(arg[1:])
        elif arg.startswith("t"):
            tout = float(arg[1:])
        elif arg.startswith("c"):
            cap = int(arg[1:])  # 0=none 1=stdout 2=stderr 3=both
        elif arg.startswith("k"):
            kill = arg[1:]  # [t]ree [m]ain [n]one
        elif arg.startswith("a"):
            areq = arg[1:]  # required perms
        elif arg.startswith("i"):
            pass
        elif not arg:
            break
        else:
            t = "hook: invalid flag {} in {}"
            (log or print)(t.format(arg, ocmd))

    env = os.environ.copy()
    try:
        if EXE:
            raise Exception()

        pypath = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
        zsl = [str(pypath)] + [str(x) for x in sys.path if x]
        pypath = str(os.pathsep.join(zsl))
        env["PYTHONPATH"] = pypath
    except:
        if not EXE:
            raise

    sp_ka = {
        "env": env,
        "nice": True,
        "oom": 300,
        "timeout": tout,
        "kill": kill,
        "capture": cap,
    }

    argv = cmd.split(",") if "," in cmd else [cmd]

    argv[0] = os.path.expandvars(os.path.expanduser(argv[0]))

    return areq, chk, fork, jtxt, wait, sp_ka, argv


def runihook(
    log ,
    verbose ,
    cmd ,
    vol ,
    ups       ,
)  :
    _, chk, fork, jtxt, wait, sp_ka, acmd = _parsehook(log, cmd)
    bcmd = [sfsenc(x) for x in acmd]
    if acmd[0].endswith(".py"):
        bcmd = [sfsenc(pybin)] + bcmd

    vps = [vjoin(*list(s3dec(x[3], x[4]))) for x in ups]
    aps = [djoin(vol.realpath, x) for x in vps]
    if jtxt:
        # 0w 1mt 2sz 3rd 4fn 5ip 6at
        ja = [
            {
                "ap": uncify(ap),  # utf8 for json
                "vp": vp,
                "wark": x[0][:16],
                "mt": x[1],
                "sz": x[2],
                "ip": x[5],
                "at": x[6],
            }
            for x, vp, ap in zip(ups, vps, aps)
        ]
        sp_ka["sin"] = json.dumps(ja).encode("utf-8", "replace")
    else:
        sp_ka["sin"] = b"\n".join(fsenc(x) for x in aps)

    if acmd[0].startswith("zmq:"):
        try:
            msg = sp_ka["sin"].decode("utf-8", "replace")
            _zmq_hook(log, verbose, "xiu", acmd[0][4:].lower(), msg, wait, sp_ka)
            if verbose and log:
                log("hook(xiu) %r OK" % (cmd,), 6)
        except Exception as ex:
            if log:
                log("zeromq failed: %r" % (ex,))
        return True

    t0 = time.time()
    if fork:
        Daemon(runcmd, cmd, bcmd, ka=sp_ka)
    else:
        rc, v, err = runcmd(bcmd, **sp_ka)  # type: ignore
        if chk and rc:
            retchk(rc, bcmd, err, log, 5)
            return False

    if wait:
        wait -= time.time() - t0
        if wait > 0:
            time.sleep(wait)

    return True


ZMQ = {}
ZMQ_DESC = {
    "pub": "fire-and-forget to all/any connected SUB-clients",
    "push": "fire-and-forget to one of the connected PULL-clients",
    "req": "send messages to a REP-server and blocking-wait for ack",
}


def _zmq_hook(
    log ,
    verbose ,
    src ,
    cmd ,
    msg ,
    wait ,
    sp_ka  ,
)   :
    import zmq

    try:
        mtx = ZMQ["mtx"]
    except:
        ZMQ["mtx"] = threading.Lock()
        time.sleep(0.1)
        mtx = ZMQ["mtx"]

    ret = ""
    nret = 0
    t0 = time.time()
    if verbose and log:
        log("hook(%s) %r entering zmq-main-lock" % (src, cmd), 6)

    with mtx:
        try:
            mode, sck, mtx = ZMQ[cmd]
        except:
            mode, uri = cmd.split(":", 1)
            try:
                desc = ZMQ_DESC[mode]
                if log:
                    t = "libzmq(%s) pyzmq(%s) init(%s); %s"
                    log(t % (zmq.zmq_version(), zmq.__version__, cmd, desc))
            except:
                raise Exception("the only supported ZMQ modes are REQ PUB PUSH")

            try:
                ctx = ZMQ["ctx"]
            except:
                ctx = ZMQ["ctx"] = zmq.Context()

            timeout = sp_ka["timeout"]

            if mode == "pub":
                sck = ctx.socket(zmq.PUB)
                sck.setsockopt(zmq.LINGER, 0)
                sck.bind(uri)
                time.sleep(1)  # give clients time to connect; avoids losing first msg
            elif mode == "push":
                sck = ctx.socket(zmq.PUSH)
                if timeout:
                    sck.SNDTIMEO = int(timeout * 1000)
                sck.setsockopt(zmq.LINGER, 0)
                sck.bind(uri)
            elif mode == "req":
                sck = ctx.socket(zmq.REQ)
                if timeout:
                    sck.RCVTIMEO = int(timeout * 1000)
                sck.setsockopt(zmq.LINGER, 0)
                sck.connect(uri)
            else:
                raise Exception()

            mtx = threading.Lock()
            ZMQ[cmd] = (mode, sck, mtx)

    if verbose and log:
        log("hook(%s) %r entering socket-lock" % (src, cmd), 6)

    with mtx:
        if verbose and log:
            log("hook(%s) %r sending |%d|" % (src, cmd, len(msg)), 6)

        sck.send_string(msg)  # PUSH can safely timeout here

        if mode == "req":
            if verbose and log:
                log("hook(%s) %r awaiting ack from req" % (src, cmd), 6)
            try:
                ret = sck.recv().decode("utf-8", "replace")
                if ret.startswith("return "):
                    m = re.search("^return ([0-9]+)", ret[:12])
                    if m:
                        nret = int(m.group(1))
            except:
                sck.close()
                del ZMQ[cmd]  # bad state; must reset
                raise Exception("ack timeout; zmq socket killed")

    if ret and log:
        log("hook(%s) %r ACK: %r" % (src, cmd, ret), 6)

    if wait:
        wait -= time.time() - t0
        if wait > 0:
            time.sleep(wait)

    return nret, ret


def _runhook(
    log ,
    verbose ,
    src ,
    cmd ,
    ap ,
    vp ,
    host ,
    uname ,
    perms ,
    mt ,
    sz ,
    ip ,
    at ,
    txt ,
)   :
    ret = {"rc": 0}
    areq, chk, fork, jtxt, wait, sp_ka, acmd = _parsehook(log, cmd)
    if areq:
        for ch in areq:
            if ch not in perms:
                t = "user %s not allowed to run hook %s; need perms %s, have %s"
                if log:
                    log(t % (uname, cmd, areq, perms))
                return ret  # fallthrough to next hook
    if jtxt:
        ja = {
            "ap": ap,
            "vp": vp,
            "mt": mt,
            "sz": sz,
            "ip": ip,
            "at": at or time.time(),
            "host": host,
            "user": uname,
            "perms": perms,
            "src": src,
            "txt": txt,
        }
        arg = json.dumps(ja)
    else:
        arg = txt or ap

    if acmd[0].startswith("zmq:"):
        zi, zs = _zmq_hook(log, verbose, src, acmd[0][4:].lower(), arg, wait, sp_ka)
        if zi:
            raise Exception("zmq says %d" % (zi,))
        return {"rc": 0, "stdout": zs}

    acmd += [arg]
    if acmd[0].endswith(".py"):
        acmd = [pybin] + acmd

    bcmd = [fsenc(x) if x == ap else sfsenc(x) for x in acmd]

    t0 = time.time()
    if fork:
        Daemon(runcmd, cmd, [bcmd], ka=sp_ka)
    else:
        rc, v, err = runcmd(bcmd, **sp_ka)  # type: ignore
        if chk and rc:
            ret["rc"] = rc
            retchk(rc, bcmd, err, log, 5)
        else:
            try:
                ret = json.loads(v)
            except:
                ret = {}

            try:
                if "stdout" not in ret:
                    ret["stdout"] = v
                if "rc" not in ret:
                    ret["rc"] = rc
            except:
                ret = {"rc": rc, "stdout": v}

    if wait:
        wait -= time.time() - t0
        if wait > 0:
            time.sleep(wait)

    return ret


def runhook(
    log ,
    broker ,
    up2k ,
    src ,
    cmds ,
    ap ,
    vp ,
    host ,
    uname ,
    perms ,
    mt ,
    sz ,
    ip ,
    at ,
    txt ,
)   :
    args = (broker or up2k).args
    verbose = args.hook_v
    vp = vp.replace("\\", "/")
    ret = {"rc": 0}
    for cmd in cmds:
        try:
            hr = _runhook(
                log, verbose, src, cmd, ap, vp, host, uname, perms, mt, sz, ip, at, txt
            )
            if verbose and log:
                log("hook(%s) %r => \033[32m%s" % (src, cmd, hr), 6)
            if not hr:
                return {}
            for k, v in hr.items():
                if k in ("idx", "del") and v:
                    if broker:
                        broker.say("up2k.hook_fx", k, v, vp)
                    else:
                        up2k.fx_backlog.append((k, v, vp))
                elif k == "reloc" and v:
                    # idk, just take the last one ig
                    ret["reloc"] = v
                elif k in ret:
                    if k == "rc" and v:
                        ret[k] = v
                    elif k == "stdout" and v and not ret[k]:
                        ret[k] = v
                else:
                    ret[k] = v
        except Exception as ex:
            (log or print)("hook: {}".format(ex))
            if ",c," in "," + cmd:
                return {}
            break

    return ret


def loadpy(ap , hot )  :
    """
    a nice can of worms capable of causing all sorts of bugs
    depending on what other inconveniently named files happen
    to be in the same folder
    """
    ap = os.path.expandvars(os.path.expanduser(ap))
    mdir, mfile = os.path.split(absreal(ap))
    mname = mfile.rsplit(".", 1)[0]
    sys.path.insert(0, mdir)

    if PY2:
        mod = __import__(mname)
        if hot:
            reload(mod)  # type: ignore
    else:
        import importlib

        mod = importlib.import_module(mname)
        if hot:
            importlib.reload(mod)

    sys.path.remove(mdir)
    return mod


def gzip_orig_sz(fn )  :
    with open(fsenc(fn), "rb") as f:
        return gzip_file_orig_sz(f)


def gzip_file_orig_sz(f)  :
    start = f.tell()
    f.seek(-4, 2)
    rv = f.read(4)
    f.seek(start, 0)
    return sunpack(b"I", rv)[0]  # type: ignore


def align_tab(lines )  :
    rows = []
    ncols = 0
    for ln in lines:
        row = [x for x in ln.split(" ") if x]
        ncols = max(ncols, len(row))
        rows.append(row)

    lens = [0] * ncols
    for row in rows:
        for n, col in enumerate(row):
            lens[n] = max(lens[n], len(col))

    return ["".join(x.ljust(y + 2) for x, y in zip(row, lens)) for row in rows]


def visual_length(txt )  :
    # from r0c
    eoc = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    clen = 0
    pend = None
    counting = True
    for ch in txt:

        # escape sequences can never contain ESC;
        # treat pend as regular text if so
        if ch == "\033" and pend:
            clen += len(pend)
            counting = True
            pend = None

        if not counting:
            if ch in eoc:
                counting = True
        else:
            if pend:
                pend += ch
                if pend.startswith("\033["):
                    counting = False
                else:
                    clen += len(pend)
                    counting = True
                pend = None
            else:
                if ch == "\033":
                    pend = "%s" % (ch,)
                else:
                    co = ord(ch)
                    # the safe parts of latin1 and cp437 (no greek stuff)
                    if (
                        co < 0x100  # ascii + lower half of latin1
                        or (co >= 0x2500 and co <= 0x25A0)  # box drawings
                        or (co >= 0x2800 and co <= 0x28FF)  # braille
                    ):
                        clen += 1
                    else:
                        # assume moonrunes or other double-width
                        clen += 2
    return clen


def wrap(txt , maxlen , maxlen2 )  :
    # from r0c
    words = re.sub(r"([, ])", r"\1\n", txt.rstrip()).split("\n")
    pad = maxlen - maxlen2
    ret = []
    for word in words:
        if len(word) * 2 < maxlen or visual_length(word) < maxlen:
            ret.append(word)
        else:
            while visual_length(word) >= maxlen:
                ret.append(word[: maxlen - 1] + "-")
                word = word[maxlen - 1 :]
            if word:
                ret.append(word)

    words = ret
    ret = []
    ln = ""
    spent = 0
    for word in words:
        wl = visual_length(word)
        if spent + wl > maxlen:
            ret.append(ln)
            maxlen = maxlen2
            spent = 0
            ln = " " * pad
        ln += word
        spent += wl
    if ln:
        ret.append(ln)

    return ret


def termsize()   :
    # from hashwalk
    env = os.environ

    def ioctl_GWINSZ(fd )   :
        try:
            cr = sunpack(b"hh", fcntl.ioctl(fd, termios.TIOCGWINSZ, b"AAAA"))
            return cr[::-1]
        except:
            return None

    cr = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)
    if not cr:
        try:
            fd = os.open(os.ctermid(), os.O_RDONLY)
            cr = ioctl_GWINSZ(fd)
            os.close(fd)
        except:
            pass

    try:
        return cr or (int(env["COLUMNS"]), int(env["LINES"]))
    except:
        return 80, 25


def hidedir(dp)  :
    if ANYWIN:
        try:
            k32 = ctypes.WinDLL("kernel32")
            attrs = k32.GetFileAttributesW(dp)
            if attrs >= 0:
                k32.SetFileAttributesW(dp, attrs | 2)
        except:
            pass


_flocks = {}


def _lock_file_noop(ap )  :
    return True


def _lock_file_ioctl(ap )  :
    try:
        fd = _flocks.pop(ap)
        os.close(fd)
    except:
        pass

    fd = os.open(ap, os.O_RDWR | os.O_CREAT, 438)
    # NOTE: the fcntl.lockf identifier is (pid,node);
    #  the lock will be dropped if os.close(os.open(ap))
    #  is performed anywhere else in this thread

    try:
        fcntl.lockf(fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
        _flocks[ap] = fd
        return True
    except Exception as ex:
        eno = getattr(ex, "errno", -1)
        try:
            os.close(fd)
        except:
            pass
        if eno in (errno.EAGAIN, errno.EACCES):
            return False
        print("WARNING: unexpected errno %d from fcntl.lockf; %r" % (eno, ex))
        return True


def _lock_file_windows(ap )  :
    try:
        import msvcrt

        try:
            fd = _flocks.pop(ap)
            os.close(fd)
        except:
            pass

        fd = os.open(ap, os.O_RDWR | os.O_CREAT, 438)
        msvcrt.locking(fd, msvcrt.LK_NBLCK, 1)
        return True
    except Exception as ex:
        eno = getattr(ex, "errno", -1)
        if eno == errno.EACCES:
            return False
        print("WARNING: unexpected errno %d from msvcrt.locking; %r" % (eno, ex))
        return True


if os.environ.get("PRTY_NO_DB_LOCK"):
    lock_file = _lock_file_noop
elif ANYWIN:
    lock_file = _lock_file_windows
elif HAVE_FCNTL:
    lock_file = _lock_file_ioctl
else:
    lock_file = _lock_file_noop


try:
    if sys.version_info < (3, 10) or os.environ.get("PRTY_NO_IMPRESO"):
        # py3.8 doesn't have .files
        # py3.9 has broken .is_file
        raise ImportError()
    import importlib.resources as impresources
except ImportError:
    try:
        import importlib_resources as impresources
    except ImportError:
        impresources = None
try:
    if sys.version_info > (3, 10):
        raise ImportError()
    import pkg_resources
except ImportError:
    pkg_resources = None


def _pkg_resource_exists(pkg , name )  :
    if not pkg_resources:
        return False
    try:
        return pkg_resources.resource_exists(pkg, name)
    except NotImplementedError:
        return False


def stat_resource(E , name ):
    path = os.path.join(E.mod, name)
    if os.path.exists(path):
        return os.stat(fsenc(path))
    return None


def _find_impresource(pkg , name ):
    try:
        files = impresources.files(pkg)
    except ImportError:
        return None

    return files.joinpath(name)


_rescache_has = {}


def _has_resource(name ):
    try:
        return _rescache_has[name]
    except:
        pass

    if len(_rescache_has) > 999:
        _rescache_has.clear()

    pkg = sys.modules[__package__]

    if impresources:
        res = _find_impresource(pkg, name)
        if res and res.is_file():
            _rescache_has[name] = True
            return True

    if pkg_resources:
        if _pkg_resource_exists(pkg.__name__, name):
            _rescache_has[name] = True
            return True

    _rescache_has[name] = False
    return False


def has_resource(E , name ):
    return _has_resource(name) or os.path.exists(os.path.join(E.mod, name))


def load_resource(E , name , mode="rb")  :
    enc = None if "b" in mode else "utf-8"

    if impresources:
        res = _find_impresource(sys.modules[__package__], name)
        if res and res.is_file():
            if enc:
                return res.open(mode, encoding=enc)
            else:
                # throws if encoding= is mentioned at all
                return res.open(mode)

    if pkg_resources:
        pkg = sys.modules[__package__]
        if _pkg_resource_exists(pkg.__name__, name):
            stream = pkg_resources.resource_stream(pkg.__name__, name)
            if enc:
                stream = codecs.getreader(enc)(stream)
            return stream

    return open(os.path.join(E.mod, name), mode, encoding=enc)


class Pebkac(Exception):
    def __init__(
        self, code , msg  = None, log  = None
    )  :
        super(Pebkac, self).__init__(msg or HTTPCODE[code])
        self.code = code
        self.log = log

    def __repr__(self)  :
        return "Pebkac({}, {})".format(self.code, repr(self.args))


class WrongPostKey(Pebkac):
    def __init__(
        self,
        expected ,
        got ,
        fname ,
        datagen   ,
    )  :
        msg = 'expected field "{}", got "{}"'.format(expected, got)
        super(WrongPostKey, self).__init__(422, msg)

        self.expected = expected
        self.got = got
        self.fname = fname
        self.datagen = datagen


_  = (
    gzip,
    mp,
    zlib,
    BytesIO,
    quote,
    unquote,
    SQLITE_VER,
    JINJA_VER,
    PYFTPD_VER,
    PARTFTPY_VER,
)
__all__ = [
    "gzip",
    "mp",
    "zlib",
    "BytesIO",
    "quote",
    "unquote",
    "SQLITE_VER",
    "JINJA_VER",
    "PYFTPD_VER",
    "PARTFTPY_VER",
]
