"""
Module holds all stuff regarding Grinder tool usage

Copyright 2015 BlazeMeter Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
import time
import subprocess
import os
import re
import shutil

from bzt.engine import ScenarioExecutor, Scenario, FileLister
from bzt.modules.aggregator import ConsolidatingAggregator, ResultsReader
from bzt.utils import shell_exec, MirrorsManager
from bzt.utils import unzip, RequiredTool, JavaVM, shutdown_process, TclLibrary
from bzt.six import iteritems
from bzt.modules.console import WidgetProvider, SidebarWidget


class GrinderExecutor(ScenarioExecutor, WidgetProvider, FileLister):
    """
    Grinder executor module
    """
    # OLD_DOWNLOAD_LINK = "http://switch.dl.sourceforge.net/project/grinder/The%20Grinder%203/{version}" \
    # "/grinder-{version}-binary.zip"
    DOWNLOAD_LINK = "http://sourceforge.net/projects/grinder/files/The%20Grinder%203/{version}" \
                    "/grinder-{version}-binary.zip/download"
    VERSION = "3.11"
    MIRRORS_SOURCE = "http://sourceforge.net/settings/mirror_choices?projectname=grinder&filename=The%20Grinder" \
                     "%203/{version}/grinder-{version}-binary.zip&dialog=true".format(version=VERSION)

    def __init__(self):
        super(GrinderExecutor, self).__init__()
        self.script = None

        self.properties_file = None
        self.kpi_file = None
        self.process = None
        self.start_time = None
        self.end_time = None
        self.retcode = None
        self.reader = None
        self.stdout_file = None
        self.stderr_file = None
        self.widget = None

    def __write_base_props(self, fds):
        """
        write base properties and base properties file contents to fds
        :param fds: fds
        :return:
        """
        base_props_file = self.settings.get("properties-file", "")
        if base_props_file:
            fds.write("# Base Properies File Start: %s\n" % base_props_file)
            with open(base_props_file) as bpf:
                fds.write(bpf.read())
            fds.write("# Base Properies File End: %s\n\n" % base_props_file)

        # base props
        base_props = self.settings.get("properties")
        if base_props:
            fds.write("# Base Properies Start\n")
            for key, val in iteritems(base_props):
                fds.write("%s=%s\n" % (key, val))
            fds.write("# Base Properies End\n\n")

    def __write_scenario_props(self, fds, scenario):
        """
        Write scenario props and scenario file props to fds
        :param fds:
        :param scenario: dict
        :return:
        """
        script_props_file = scenario.get("properties-file", "")
        if script_props_file:
            fds.write(
                "# Script Properies File Start: %s\n" % script_props_file)
            with open(script_props_file) as spf:
                fds.write(spf.read())
            fds.write(
                "# Script Properies File End: %s\n\n" % script_props_file)

        # scenario props
        local_props = scenario.get("properties")
        if local_props:
            fds.write("# Scenario Properies Start\n")
            for key, val in iteritems(local_props):
                fds.write("%s=%s\n" % (key, val))
            fds.write("# Scenario Properies End\n\n")

    def __write_bzt_props(self, fds):
        """
        Write bzt properties to fds
        :param fds:
        :return:
        """
        fds.write("# BZT Properies Start\n")
        fds.write("grinder.hostID=grinder-bzt\n")
        fds.write("grinder.script=%s\n" % os.path.realpath(self.script))
        dirname = os.path.realpath(self.engine.artifacts_dir)
        fds.write("grinder.logDirectory=%s\n" % dirname)

        load = self.get_load()
        if load.concurrency:
            if load.ramp_up:
                interval = int(1000 * load.ramp_up / load.concurrency)
                fds.write("grinder.processIncrementInterval=%s\n" % interval)
            fds.write("grinder.processes=%s\n" % int(load.concurrency))
            fds.write("grinder.runs=%s\n" % load.iterations)
            fds.write("grinder.processIncrement=1\n")
            if load.duration:
                fds.write("grinder.duration=%s\n" % int(load.duration * 1000))
        fds.write("# BZT Properies End\n")

    def prepare(self):
        self._check_installed()

        scenario = self.get_scenario()

        if Scenario.SCRIPT in scenario:
            self.script = self.engine.find_file(scenario[Scenario.SCRIPT])
            self.engine.existing_artifact(self.script)
        elif "requests" in scenario:
            self.script = self.__scenario_from_requests()
        else:
            raise ValueError("There must be a scenario file to run Grinder")

        self.properties_file = self.engine.create_artifact("grinder", ".properties")

        with open(self.properties_file, 'w') as fds:
            self.__write_base_props(fds)
            self.__write_scenario_props(fds, scenario)
            self.__write_bzt_props(fds)

        with open(self.properties_file, 'rt') as fds:
            prop_contents = fds.read()
        resource_files, modified_contents = self.__get_res_files_from_script(prop_contents)
        if resource_files:
            with open(self.properties_file, 'wt') as fds:
                fds.write(modified_contents)

        # TODO: multi-grinder executions to have different names
        self.kpi_file = os.path.join(self.engine.artifacts_dir, "grinder-bzt-kpi.log")

        self.reader = DataLogReader(self.kpi_file, self.log)
        if isinstance(self.engine.aggregator, ConsolidatingAggregator):
            self.engine.aggregator.add_underling(self.reader)

    def startup(self):
        """
        Should start the tool as fast as possible.
        """
        classpath = os.path.join(os.path.dirname(__file__), os.pardir, 'resources')
        classpath += os.path.pathsep + os.path.realpath(self.settings.get("path"))
        cmdline = ["java", "-classpath", classpath]
        cmdline += ["net.grinder.Grinder", self.properties_file]

        self.start_time = time.time()
        out = self.engine.create_artifact("grinder-stdout", ".log")
        err = self.engine.create_artifact("grinder-stderr", ".log")
        self.stdout_file = open(out, "w")
        self.stderr_file = open(err, "w")
        self.process = shell_exec(cmdline, cwd=self.engine.artifacts_dir,
                                  stdout=self.stdout_file,
                                  stderr=self.stderr_file)

    def check(self):
        """
        Checks if tool is still running. Also checks if resulting logs contains
        any data and throws exception otherwise.

        :return: bool
        :raise RuntimeWarning:
        """
        if self.widget:
            self.widget.update()

        self.retcode = self.process.poll()
        if self.retcode is not None:
            if self.retcode != 0:
                self.log.info("Grinder exit code: %s", self.retcode)
                raise RuntimeError("Grinder exited with non-zero code")

            if self.kpi_file:
                if not os.path.exists(self.kpi_file) \
                        or not os.path.getsize(self.kpi_file):
                    msg = "Empty results log, most likely the tool failed: %s"
                    raise RuntimeWarning(msg % self.kpi_file)

            return True
        return False

    def shutdown(self):
        """
        If tool is still running - let's stop it.
        """
        shutdown_process(self.process, self.log)

        if self.stdout_file:
            self.stdout_file.close()
        if self.stderr_file:
            self.stderr_file.close()

        if self.start_time:
            self.end_time = time.time()
            self.log.debug("Grinder worked for %s seconds", self.end_time - self.start_time)

    def post_process(self):
        """
        Collect data file artifact
        """
        if self.kpi_file:
            self.engine.existing_artifact(self.kpi_file)
        if self.reader and not self.reader.buffer:
            raise RuntimeWarning("Empty results, most likely Grinder failed")

    def __scenario_from_requests(self):
        """
        Generate grinder scenario from requests
        :return: script
        """
        script = self.engine.create_artifact("requests", ".py")
        tpl = os.path.join(os.path.dirname(__file__), os.pardir, 'resources', "grinder-requests.tpl")
        self.log.debug("Generating grinder scenario: %s", tpl)
        with open(script, 'w') as fds:
            with open(tpl) as tds:
                fds.write(tds.read())
            for req in self.get_scenario().get_requests():
                line = '\t\trequest.%s("%s")\n' % (req.method, req.url)
                fds.write(line)
        return script

    def _check_installed(self):
        grinder_path = self.settings.get("path", "~/.bzt/grinder-taurus/lib/grinder.jar")
        grinder_path = os.path.abspath(os.path.expanduser(grinder_path))
        self.settings["path"] = grinder_path
        required_tools = [TclLibrary(self.log),
                          JavaVM("", "", self.log),
                          Grinder(grinder_path, self.log, GrinderExecutor.VERSION)]

        for tool in required_tools:
            if not tool.check_if_installed():
                self.log.info("Installing %s", tool.tool_name)
                tool.install()

    def get_widget(self):
        if not self.widget:
            if self.script is not None:
                label = "Script: %s" % os.path.basename(self.script)
            else:
                label = None
            self.widget = SidebarWidget(self, label)
        return self.widget

    def resource_files(self):
        resource_files = []
        prop_file = self.get_scenario().get("properties-file", None)

        if prop_file:
            prop_file = self.engine.find_file(prop_file)
            prop_file_contents = open(prop_file, 'rt').read()
            resource_files, modified_contents = self.__get_res_files_from_script(prop_file_contents)
            if resource_files:
                self.__cp_res_files_to_artifacts_dir(resource_files)
                script_name, script_ext = os.path.splitext(prop_file)
                script_name = os.path.basename(script_name)
                modified_script = self.engine.create_artifact(script_name, script_ext)
                with open(modified_script, 'wt') as _fds:
                    _fds.write(modified_contents)
                resource_files.append(modified_script)
            else:
                shutil.copy2(prop_file, self.engine.artifacts_dir)
                resource_files.append(prop_file)

        return [os.path.basename(x) for x in resource_files]

    def __cp_res_files_to_artifacts_dir(self, resource_files_list):
        """

        :param resource_files_list:
        :return:
        """
        for resource_file in resource_files_list:
            if os.path.exists(resource_file):
                try:
                    shutil.copy(resource_file, self.engine.artifacts_dir)
                except BaseException:
                    self.log.warning("Cannot copy file: %s", resource_file)
            else:
                self.log.warning("File not found: %s", resource_file)

    def __get_res_files_from_script(self, prop_file_contents):
        """
        if "script" in scenario:
            add script file to resources and override script name in .prop file
        else:
            take script name from .prop file and add it to resources

        :param prop_file_contents:
        :return: list of resource files and contents of .prop file
        """
        resource_files = []
        script_file_path = self.get_scenario().get("script")

        search_pattern = re.compile(r"grinder\.script.*")
        found_pattern = search_pattern.findall(prop_file_contents)[-1]  # take last
        file_path_in_prop = found_pattern.split("=")[-1].strip()

        if script_file_path:
            resource_files.append(script_file_path)
            prop_file_contents = prop_file_contents.replace(file_path_in_prop, os.path.basename(script_file_path))
        else:
            resource_files.append(file_path_in_prop)

        return resource_files, prop_file_contents


class DataLogReader(ResultsReader):
    """ Class to read KPI from data log """

    def __init__(self, filename, parent_logger):
        super(DataLogReader, self).__init__()
        self.log = parent_logger.getChild(self.__class__.__name__)
        self.filename = filename
        self.fds = None
        self.idx = {}
        self.partial_buffer = ""
        self.delimiter = ","
        self.offset = 0

    def _read(self, last_pass=False):
        """
        Generator method that returns next portion of data

        :param last_pass:
        """
        while not self.fds and not self.__open_fds():
            self.log.debug("No data to start reading yet")
            yield None

        self.log.debug("Reading grinder results")
        self.fds.seek(self.offset)  # without this we have a stuck reads on Mac
        if last_pass:
            lines = self.fds.readlines()  # unlimited
        else:
            lines = self.fds.readlines(1024 * 1024)  # 1MB limit to read
        self.offset = self.fds.tell()

        for line in lines:
            if not line.endswith("\n"):
                self.partial_buffer += line
                continue

            line = "%s%s" % (self.partial_buffer, line)
            self.partial_buffer = ""

            line = line.strip()
            fields = line.split(self.delimiter)
            if not fields[1].strip().isdigit():
                self.log.debug("Skipping line: %s", line)
                continue
            t_stamp = int(fields[self.idx["Start time (ms since Epoch)"]]) / 1000.0
            label = ""
            r_time = int(fields[self.idx["Test time"]]) / 1000.0
            latency = int(fields[self.idx["Time to first byte"]]) / 1000.0
            r_code = fields[self.idx["HTTP response code"]].strip()
            con_time = int(fields[self.idx["Time to resolve host"]]) / 1000.0
            con_time += int(fields[self.idx["Time to establish connection"]]) / 1000.0
            if int(fields[self.idx["Errors"]]):
                error = "There were some errors in Grinder test"
            else:
                error = None
            concur = None  # TODO: how to get this for grinder
            yield int(t_stamp), label, concur, r_time, con_time, latency, r_code, error, ''

    def __open_fds(self):
        """
        opens grinder-bzt-kpi.log
        """
        if not os.path.isfile(self.filename):
            self.log.debug("File not appeared yet")
            return False

        if not os.path.getsize(self.filename):
            self.log.debug("File is empty: %s", self.filename)
            return False

        self.fds = open(self.filename)
        header = self.fds.readline().strip().split(self.delimiter)
        for _ix, field in enumerate(header):
            self.idx[field.strip()] = _ix
        return True


class Grinder(RequiredTool):
    def __init__(self, tool_path, parent_logger, version):
        super(Grinder, self).__init__("Grinder", tool_path)
        self.log = parent_logger.getChild(self.__class__.__name__)
        self.version = version
        self.mirror_manager = GrinderMirrorsManager(self.log, self.version)

    def check_if_installed(self):
        self.log.debug("Trying grinder: %s", self.tool_path)
        grinder_launch_command = ["java", "-classpath", self.tool_path, "net.grinder.Grinder"]
        grinder_subprocess = shell_exec(grinder_launch_command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
        output = grinder_subprocess.communicate()
        self.log.debug("%s output: %s", self.tool_name, output)
        if grinder_subprocess.returncode == 0:
            self.already_installed = True
            return True
        else:
            return False

    def install(self):
        dest = os.path.dirname(os.path.dirname(os.path.expanduser(self.tool_path)))
        dest = os.path.abspath(dest)
        grinder_dist = super(Grinder, self).install_with_mirrors(dest, ".zip")
        self.log.info("Unzipping %s", grinder_dist.name)
        unzip(grinder_dist.name, dest, 'grinder-' + self.version)
        grinder_dist.close()
        os.remove(grinder_dist.name)
        self.log.info("Installed grinder successfully")
        if not self.check_if_installed():
            raise RuntimeError("Unable to run %s after installation!" % self.tool_name)


class GrinderMirrorsManager(MirrorsManager):
    def __init__(self, parent_logger, grinder_version):
        self.grinder_version = grinder_version
        super(GrinderMirrorsManager, self).__init__(GrinderExecutor.MIRRORS_SOURCE, parent_logger)

    def _parse_mirrors(self):
        links = []
        if self.page_source is not None:
            self.log.debug('Parsing mirrors...')
            base_link = "http://sourceforge.net/projects/grinder/files/The%20Grinder%203/{version}/grinder-{version}" \
                        "-binary.zip/download?use_mirror={mirror}"
            li_search_pattern = re.compile(r'<li id=".*?">')
            li_elements = li_search_pattern.findall(self.page_source)
            if li_elements:
                links = [base_link.format(version=self.grinder_version, mirror=link.strip('<li id="').strip('">')) for
                         link in li_elements]
        default_link = GrinderExecutor.DOWNLOAD_LINK.format(version=self.grinder_version)
        if default_link not in links:
            links.append(default_link)
        self.log.debug('Total mirrors: %d', len(links))
        return links
