"""QQ channel implementation using botpy SDK.

Inbound:
- Parse QQ botpy messages (C2C / Group)
- Download attachments to media dir using chunked streaming write (memory-safe)
- Publish to Nanobot bus via BaseChannel._handle_message()
- Content includes a clear, actionable "Received files:" list with local paths

Outbound:
- Send attachments (msg.media) first via QQ rich media API (base64 upload + msg_type=7)
- Then send text (plain or markdown)
- msg.media supports local paths, file:// paths, and http(s) URLs

Notes:
- QQ restricts many audio/video formats. We conservatively classify as image vs file.
- Attachment structures differ across botpy versions; we try multiple field candidates.
"""

from __future__ import annotations

import asyncio
import base64
import mimetypes
import os
import re
import time
from collections import deque
from pathlib import Path
from typing import TYPE_CHECKING, Any, Literal
from urllib.parse import unquote, urlparse

import aiohttp
from loguru import logger
from pydantic import Field

from nanobot.bus.events import OutboundMessage
from nanobot.bus.queue import MessageBus
from nanobot.channels.base import BaseChannel
from nanobot.config.schema import Base
from nanobot.security.network import validate_url_target

try:
    from nanobot.config.paths import get_media_dir
except Exception:  # pragma: no cover
    get_media_dir = None  # type: ignore

try:
    import botpy
    from botpy.http import Route

    QQ_AVAILABLE = True
except ImportError:  # pragma: no cover
    QQ_AVAILABLE = False
    botpy = None
    Route = None

if TYPE_CHECKING:
    from botpy.message import BaseMessage, C2CMessage, GroupMessage
    from botpy.types.message import Media


# QQ rich media file_type: 1=image, 4=file
# (2=voice, 3=video are restricted; we only use image vs file)
QQ_FILE_TYPE_IMAGE = 1
QQ_FILE_TYPE_FILE = 4

_IMAGE_EXTS = {
    ".png",
    ".jpg",
    ".jpeg",
    ".gif",
    ".bmp",
    ".webp",
    ".tif",
    ".tiff",
    ".ico",
    ".svg",
}

# Replace unsafe characters with "_", keep Chinese and common safe punctuation.
_SAFE_NAME_RE = re.compile(r"[^\w.\-()\[\]（）【】\u4e00-\u9fff]+", re.UNICODE)


def _sanitize_filename(name: str) -> str:
    """Sanitize filename to avoid traversal and problematic chars."""
    name = (name or "").strip()
    name = Path(name).name
    name = _SAFE_NAME_RE.sub("_", name).strip("._ ")
    return name


def _is_image_name(name: str) -> bool:
    return Path(name).suffix.lower() in _IMAGE_EXTS


def _guess_send_file_type(filename: str) -> int:
    """Conservative send type: images -> 1, else -> 4."""
    ext = Path(filename).suffix.lower()
    mime, _ = mimetypes.guess_type(filename)
    if ext in _IMAGE_EXTS or (mime and mime.startswith("image/")):
        return QQ_FILE_TYPE_IMAGE
    return QQ_FILE_TYPE_FILE


def _make_bot_class(channel: QQChannel) -> type[botpy.Client]:
    """Create a botpy Client subclass bound to the given channel."""
    intents = botpy.Intents(public_messages=True, direct_message=True)

    class _Bot(botpy.Client):
        def __init__(self):
            # Disable botpy's file log — nanobot uses loguru; default "botpy.log" fails on read-only fs
            super().__init__(intents=intents, ext_handlers=False)

        async def on_ready(self):
            logger.info("QQ bot ready: {}", self.robot.name)

        async def on_c2c_message_create(self, message: C2CMessage):
            await channel._on_message(message, is_group=False)

        async def on_group_at_message_create(self, message: GroupMessage):
            await channel._on_message(message, is_group=True)

        async def on_direct_message_create(self, message):
            await channel._on_message(message, is_group=False)

    return _Bot


class QQConfig(Base):
    """QQ channel configuration using botpy SDK."""

    enabled: bool = False
    app_id: str = ""
    secret: str = ""
    allow_from: list[str] = Field(default_factory=list)
    msg_format: Literal["plain", "markdown"] = "plain"

    # Optional: directory to save inbound attachments. If empty, use nanobot get_media_dir("qq").
    media_dir: str = ""

    # Download tuning
    download_chunk_size: int = 1024 * 256  # 256KB
    download_max_bytes: int = 1024 * 1024 * 200  # 200MB safety limit


class QQChannel(BaseChannel):
    """QQ channel using botpy SDK with WebSocket connection."""

    name = "qq"
    display_name = "QQ"

    @classmethod
    def default_config(cls) -> dict[str, Any]:
        return QQConfig().model_dump(by_alias=True)

    def __init__(self, config: Any, bus: MessageBus):
        if isinstance(config, dict):
            config = QQConfig.model_validate(config)
        super().__init__(config, bus)
        self.config: QQConfig = config

        self._client: botpy.Client | None = None
        self._http: aiohttp.ClientSession | None = None

        self._processed_ids: deque[str] = deque(maxlen=1000)
        self._msg_seq: int = 1  # used to avoid QQ API dedup
        self._chat_type_cache: dict[str, str] = {}

        self._media_root: Path = self._init_media_root()

    # ---------------------------
    # Lifecycle
    # ---------------------------

    def _init_media_root(self) -> Path:
        """Choose a directory for saving inbound attachments."""
        if self.config.media_dir:
            root = Path(self.config.media_dir).expanduser()
        elif get_media_dir:
            try:
                root = Path(get_media_dir("qq"))
            except Exception:
                root = Path.home() / ".nanobot" / "media" / "qq"
        else:
            root = Path.home() / ".nanobot" / "media" / "qq"

        root.mkdir(parents=True, exist_ok=True)
        logger.info("QQ media directory: {}", str(root))
        return root

    async def start(self) -> None:
        """Start the QQ bot with auto-reconnect loop."""
        if not QQ_AVAILABLE:
            logger.error("QQ SDK not installed. Run: pip install qq-botpy")
            return

        if not self.config.app_id or not self.config.secret:
            logger.error("QQ app_id and secret not configured")
            return

        self._running = True
        self._http = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=120))

        self._client = _make_bot_class(self)()
        logger.info("QQ bot started (C2C & Group supported)")
        await self._run_bot()

    async def _run_bot(self) -> None:
        """Run the bot connection with auto-reconnect."""
        while self._running:
            try:
                await self._client.start(appid=self.config.app_id, secret=self.config.secret)
            except Exception as e:
                logger.warning("QQ bot error: {}", e)
            if self._running:
                logger.info("Reconnecting QQ bot in 5 seconds...")
                await asyncio.sleep(5)

    async def stop(self) -> None:
        """Stop bot and cleanup resources."""
        self._running = False
        if self._client:
            try:
                await self._client.close()
            except Exception:
                pass
        self._client = None

        if self._http:
            try:
                await self._http.close()
            except Exception:
                pass
        self._http = None

        logger.info("QQ bot stopped")

    # ---------------------------
    # Outbound (send)
    # ---------------------------

    async def send(self, msg: OutboundMessage) -> None:
        """Send attachments first, then text."""
        if not self._client:
            logger.warning("QQ client not initialized")
            return

        msg_id = msg.metadata.get("message_id")
        chat_type = self._chat_type_cache.get(msg.chat_id, "c2c")
        is_group = chat_type == "group"

        # 1) Send media
        for media_ref in msg.media or []:
            ok = await self._send_media(
                chat_id=msg.chat_id,
                media_ref=media_ref,
                msg_id=msg_id,
                is_group=is_group,
            )
            if not ok:
                filename = (
                    os.path.basename(urlparse(media_ref).path)
                    or os.path.basename(media_ref)
                    or "file"
                )
                await self._send_text_only(
                    chat_id=msg.chat_id,
                    is_group=is_group,
                    msg_id=msg_id,
                    content=f"[Attachment send failed: {filename}]",
                )

        # 2) Send text
        if msg.content and msg.content.strip():
            await self._send_text_only(
                chat_id=msg.chat_id,
                is_group=is_group,
                msg_id=msg_id,
                content=msg.content.strip(),
            )

    async def _send_text_only(
        self,
        chat_id: str,
        is_group: bool,
        msg_id: str | None,
        content: str,
    ) -> None:
        """Send a plain/markdown text message."""
        if not self._client:
            return

        self._msg_seq += 1
        use_markdown = self.config.msg_format == "markdown"
        payload: dict[str, Any] = {
            "msg_type": 2 if use_markdown else 0,
            "msg_id": msg_id,
            "msg_seq": self._msg_seq,
        }
        if use_markdown:
            payload["markdown"] = {"content": content}
        else:
            payload["content"] = content

        if is_group:
            await self._client.api.post_group_message(group_openid=chat_id, **payload)
        else:
            await self._client.api.post_c2c_message(openid=chat_id, **payload)

    async def _send_media(
        self,
        chat_id: str,
        media_ref: str,
        msg_id: str | None,
        is_group: bool,
    ) -> bool:
        """Read bytes -> base64 upload -> msg_type=7 send."""
        if not self._client:
            return False

        data, filename = await self._read_media_bytes(media_ref)
        if not data or not filename:
            return False

        try:
            file_type = _guess_send_file_type(filename)
            file_data_b64 = base64.b64encode(data).decode()

            media_obj = await self._post_base64file(
                chat_id=chat_id,
                is_group=is_group,
                file_type=file_type,
                file_data=file_data_b64,
                file_name=filename,
                srv_send_msg=False,
            )
            if not media_obj:
                logger.error("QQ media upload failed: empty response")
                return False

            self._msg_seq += 1
            if is_group:
                await self._client.api.post_group_message(
                    group_openid=chat_id,
                    msg_type=7,
                    msg_id=msg_id,
                    msg_seq=self._msg_seq,
                    media=media_obj,
                )
            else:
                await self._client.api.post_c2c_message(
                    openid=chat_id,
                    msg_type=7,
                    msg_id=msg_id,
                    msg_seq=self._msg_seq,
                    media=media_obj,
                )

            logger.info("QQ media sent: {}", filename)
            return True
        except Exception as e:
            logger.error("QQ send media failed filename={} err={}", filename, e)
            return False

    async def _read_media_bytes(self, media_ref: str) -> tuple[bytes | None, str | None]:
        """Read bytes from http(s) or local file path; return (data, filename)."""
        media_ref = (media_ref or "").strip()
        if not media_ref:
            return None, None

        # Local file: plain path or file:// URI
        if not media_ref.startswith("http://") and not media_ref.startswith("https://"):
            try:
                if media_ref.startswith("file://"):
                    parsed = urlparse(media_ref)
                    # Windows: path in netloc; Unix: path in path
                    raw = parsed.path or parsed.netloc
                    local_path = Path(unquote(raw))
                else:
                    local_path = Path(os.path.expanduser(media_ref))

                if not local_path.is_file():
                    logger.warning("QQ outbound media file not found: {}", str(local_path))
                    return None, None

                data = await asyncio.to_thread(local_path.read_bytes)
                return data, local_path.name
            except Exception as e:
                logger.warning("QQ outbound media read error ref={} err={}", media_ref, e)
                return None, None

        # Remote URL
        ok, err = validate_url_target(media_ref)
        if not ok:
            logger.warning("QQ outbound media URL validation failed url={} err={}", media_ref, err)
            return None, None

        if not self._http:
            self._http = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=120))
        try:
            async with self._http.get(media_ref, allow_redirects=True) as resp:
                if resp.status >= 400:
                    logger.warning(
                        "QQ outbound media download failed status={} url={}",
                        resp.status,
                        media_ref,
                    )
                    return None, None
                data = await resp.read()
                if not data:
                    return None, None
                filename = os.path.basename(urlparse(media_ref).path) or "file.bin"
                return data, filename
        except Exception as e:
            logger.warning("QQ outbound media download error url={} err={}", media_ref, e)
            return None, None

    # https://github.com/tencent-connect/botpy/issues/198
    # https://bot.q.qq.com/wiki/develop/api-v2/server-inter/message/send-receive/rich-media.html
    async def _post_base64file(
        self,
        chat_id: str,
        is_group: bool,
        file_type: int,
        file_data: str,
        file_name: str | None = None,
        srv_send_msg: bool = False,
    ) -> Media:
        """Upload base64-encoded file and return Media object."""
        if not self._client:
            raise RuntimeError("QQ client not initialized")

        if is_group:
            endpoint = "/v2/groups/{group_openid}/files"
            id_key = "group_openid"
        else:
            endpoint = "/v2/users/{openid}/files"
            id_key = "openid"

        payload = {
            id_key: chat_id,
            "file_type": file_type,
            "file_data": file_data,
            "file_name": file_name,
            "srv_send_msg": srv_send_msg,
        }
        route = Route("POST", endpoint, **{id_key: chat_id})
        return await self._client.api._http.request(route, json=payload)

    # ---------------------------
    # Inbound (receive)
    # ---------------------------

    async def _on_message(self, data: C2CMessage | GroupMessage, is_group: bool = False) -> None:
        """Parse inbound message, download attachments, and publish to the bus."""
        if data.id in self._processed_ids:
            return
        self._processed_ids.append(data.id)

        if is_group:
            chat_id = data.group_openid
            user_id = data.author.member_openid
            self._chat_type_cache[chat_id] = "group"
        else:
            chat_id = str(
                getattr(data.author, "id", None) or getattr(data.author, "user_openid", "unknown")
            )
            user_id = chat_id
            self._chat_type_cache[chat_id] = "c2c"

        content = (data.content or "").strip()

        # the data used by tests don't contain attachments property
        # so we use getattr with a default of [] to avoid AttributeError in tests
        attachments = getattr(data, "attachments", None) or []
        media_paths, recv_lines, att_meta = await self._handle_attachments(attachments)

        # Compose content that always contains actionable saved paths
        if recv_lines:
            tag = "[Image]" if any(_is_image_name(Path(p).name) for p in media_paths) else "[File]"
            file_block = "Received files:\n" + "\n".join(recv_lines)
            content = f"{content}\n\n{file_block}".strip() if content else f"{tag}\n{file_block}"

        if not content and not media_paths:
            return

        await self._handle_message(
            sender_id=user_id,
            chat_id=chat_id,
            content=content,
            media=media_paths if media_paths else None,
            metadata={
                "message_id": data.id,
                "attachments": att_meta,
            },
        )

    async def _handle_attachments(
        self,
        attachments: list[BaseMessage._Attachments],
    ) -> tuple[list[str], list[str], list[dict[str, Any]]]:
        """Extract, download (chunked), and format attachments for agent consumption."""
        media_paths: list[str] = []
        recv_lines: list[str] = []
        att_meta: list[dict[str, Any]] = []

        if not attachments:
            return media_paths, recv_lines, att_meta

        for att in attachments:
            url, filename, ctype = att.url, att.filename, att.content_type

            logger.info("Downloading file from QQ: {}", filename or url)
            local_path = await self._download_to_media_dir_chunked(url, filename_hint=filename)

            att_meta.append(
                {
                    "url": url,
                    "filename": filename,
                    "content_type": ctype,
                    "saved_path": local_path,
                }
            )

            if local_path:
                media_paths.append(local_path)
                shown_name = filename or os.path.basename(local_path)
                recv_lines.append(f"- {shown_name}\n  saved: {local_path}")
            else:
                shown_name = filename or url
                recv_lines.append(f"- {shown_name}\n  saved: [download failed]")

        return media_paths, recv_lines, att_meta

    async def _download_to_media_dir_chunked(
        self,
        url: str,
        filename_hint: str = "",
    ) -> str | None:
        """Download an inbound attachment using streaming chunk write.

        Uses chunked streaming to avoid loading large files into memory.
        Enforces a max download size and writes to a .part temp file
        that is atomically renamed on success.
        """
        if not self._http:
            self._http = aiohttp.ClientSession(timeout=aiohttp.ClientTimeout(total=120))

        safe = _sanitize_filename(filename_hint)
        ts = int(time.time() * 1000)
        tmp_path: Path | None = None

        try:
            async with self._http.get(
                url,
                timeout=aiohttp.ClientTimeout(total=120),
                allow_redirects=True,
            ) as resp:
                if resp.status != 200:
                    logger.warning("QQ download failed: status={} url={}", resp.status, url)
                    return None

                ctype = (resp.headers.get("Content-Type") or "").lower()

                # Infer extension: url -> filename_hint -> content-type -> fallback
                ext = Path(urlparse(url).path).suffix
                if not ext:
                    ext = Path(filename_hint).suffix
                if not ext:
                    if "png" in ctype:
                        ext = ".png"
                    elif "jpeg" in ctype or "jpg" in ctype:
                        ext = ".jpg"
                    elif "gif" in ctype:
                        ext = ".gif"
                    elif "webp" in ctype:
                        ext = ".webp"
                    elif "pdf" in ctype:
                        ext = ".pdf"
                    else:
                        ext = ".bin"

                if safe:
                    if not Path(safe).suffix:
                        safe = safe + ext
                    filename = safe
                else:
                    filename = f"qq_file_{ts}{ext}"

                target = self._media_root / filename
                if target.exists():
                    target = self._media_root / f"{target.stem}_{ts}{target.suffix}"

                tmp_path = target.with_suffix(target.suffix + ".part")

                # Stream write
                downloaded = 0
                chunk_size = max(1024, int(self.config.download_chunk_size or 262144))
                max_bytes = max(
                    1024 * 1024, int(self.config.download_max_bytes or (200 * 1024 * 1024))
                )

                def _open_tmp():
                    tmp_path.parent.mkdir(parents=True, exist_ok=True)
                    return open(tmp_path, "wb")  # noqa: SIM115

                f = await asyncio.to_thread(_open_tmp)
                try:
                    async for chunk in resp.content.iter_chunked(chunk_size):
                        if not chunk:
                            continue
                        downloaded += len(chunk)
                        if downloaded > max_bytes:
                            logger.warning(
                                "QQ download exceeded max_bytes={} url={} -> abort",
                                max_bytes,
                                url,
                            )
                            return None
                        await asyncio.to_thread(f.write, chunk)
                finally:
                    await asyncio.to_thread(f.close)

                # Atomic rename
                await asyncio.to_thread(os.replace, tmp_path, target)
                tmp_path = None  # mark as moved
                logger.info("QQ file saved: {}", str(target))
                return str(target)

        except Exception as e:
            logger.error("QQ download error: {}", e)
            return None
        finally:
            # Cleanup partial file
            if tmp_path is not None:
                try:
                    tmp_path.unlink(missing_ok=True)
                except Exception:
                    pass
