import asyncio
import hashlib
import logging
import multiprocessing
import os
import re
import time
from datetime import UTC, datetime
from email.utils import formatdate
from pathlib import Path

import yt_dlp

from .config import Config
from .Events import EventBus, Events
from .ffprobe import ffprobe
from .ItemDTO import ItemDTO
from .Utils import delete_dir, extract_info, extract_ytdlp_logs, load_cookies
from .YTDLPOpts import YTDLPOpts


class Terminator:
    pass


class NestedLogger:
    debug_messages = ["[debug] ", "[download] "]

    def __init__(self, logger: logging.Logger):
        self.logger = logger

    def debug(self, msg: str):
        levelno = logging.DEBUG if any(msg.startswith(x) for x in self.debug_messages) else logging.INFO
        self.logger.log(level=levelno, msg=re.sub(r"^\[(debug|info)\] ", "", msg, flags=re.IGNORECASE))

    def error(self, msg):
        self.logger.error(msg)

    def warning(self, msg):
        self.logger.warning(msg)


class Download:
    """
    Download task.
    """

    id: str = None
    download_dir: str = None
    temp_dir: str = None
    template: str = None
    template_chapter: str = None
    info: ItemDTO = None
    debug: bool = False
    temp_path: str = None
    cancelled: bool = False
    is_live: bool = False
    info_dict: dict = None
    "yt-dlp metadata dict."
    update_task = None

    cancel_in_progress: bool = False

    bad_live_options: list = [
        "concurrent_fragment_downloads",
        "fragment_retries",
        "skip_unavailable_fragments",
    ]
    "Bad yt-dlp options which are known to cause issues with live stream."

    _ytdlp_fields: tuple = (
        "tmpfilename",
        "filename",
        "status",
        "msg",
        "total_bytes",
        "total_bytes_estimate",
        "downloaded_bytes",
        "speed",
        "eta",
    )
    "Fields to be extracted from yt-dlp progress hook."

    temp_keep: bool = False
    "Keep temp folder after download."

    logs: list = []
    "Logs from yt-dlp."

    def __init__(self, info: ItemDTO, info_dict: dict = None, logs: list | None = None):
        """
        Initialize download task.

        Args:
            info (ItemDTO): ItemDTO object.
            info_dict (dict): yt-dlp metadata dict.
            logs (list): Logs from yt-dlp.

        """
        config = Config.get_instance()

        self.download_dir = info.download_dir
        self.temp_dir = info.temp_dir
        self.template = info.template
        self.template_chapter = info.template_chapter
        self.preset = info.preset
        self.info = info
        self.id = info._id
        self.debug = bool(config.debug)
        self.debug_ytdl = bool(config.ytdl_debug)
        self.cancelled = False
        self.tmpfilename = None
        self.status_queue = None
        self.proc = None
        self._notify = EventBus.get_instance()
        self.max_workers = int(config.max_workers)
        self.temp_keep = bool(config.temp_keep)
        self.is_live = bool(info.is_live) or info.live_in is not None
        self.info_dict = info_dict
        self.logger = logging.getLogger(f"Download.{info.id if info.id else info._id}")
        self.started_time = 0
        self.queue_time = datetime.now(tz=UTC)
        self.logs = logs if logs else []

    def _progress_hook(self, data: dict):
        if self.debug:
            from copy import deepcopy

            d_copy = deepcopy(data)
            for k in ["formats", "thumbnails", "description", "tags", "_format_sort_fields"]:
                d_copy["info_dict"].pop(k, None)

            self.logger.debug(f"Progress hook: {d_copy}")

        dataDict = {k: v for k, v in data.items() if k in self._ytdlp_fields}

        if "finished" == data.get("status") and data.get("info_dict", {}).get("filename", None):
            dataDict["filename"] = data["info_dict"]["filename"]

        self.status_queue.put({"id": self.id, **dataDict})

    def _postprocessor_hook(self, data: dict):
        if self.debug:
            self.logger.debug(f"Postprocessor hook: {data}")

        if "MoveFiles" != data.get("postprocessor") or "finished" != data.get("status"):
            dataDict = {k: v for k, v in data.items() if k in self._ytdlp_fields}
            self.status_queue.put({"id": self.id, **dataDict, "status": "postprocessing"})
            return

        if "__finaldir" in data["info_dict"]:
            filename = str(Path(data["info_dict"]["__finaldir"]) / Path(data["info_dict"]["filepath"]).name)
        else:
            filename = data["info_dict"]["filepath"]

        self.status_queue.put({"id": self.id, "status": "finished", "filename": filename})

    def post_hooks(self, filename: str | None = None):
        if not filename:
            return

        self.status_queue.put({"id": self.id, "filename": filename})

    def _download(self):
        try:
            params: dict = (
                YTDLPOpts.get_instance()
                .preset(self.preset)
                .add({"break_on_existing": True})
                .add_cli(args=self.info.cli, from_user=True)
                .add(
                    config={
                        "color": "no_color",
                        "paths": {
                            "home": str(self.download_dir),
                            "temp": str(self.temp_path),
                        },
                        "outtmpl": {
                            "default": self.template,
                            "chapter": self.template_chapter,
                        },
                        "noprogress": True,
                        "ignoreerrors": False,
                    },
                    from_user=False,
                )
                .get_all()
            )

            params.update(
                {
                    "progress_hooks": [self._progress_hook],
                    "postprocessor_hooks": [self._postprocessor_hook],
                    "post_hooks": [self.post_hooks],
                }
            )

            if self.debug_ytdl:
                params["verbose"] = True
                params["noprogress"] = False

            if self.info.cookies:
                try:
                    cookie_file = Path(self.temp_path) / f"cookie_{self.info._id}.txt"
                    self.logger.debug(
                        f"Creating cookie file for '{self.info.id}: {self.info.title}' - '{cookie_file}'."
                    )
                    cookie_file.write_text(self.info.cookies)
                    params["cookiefile"] = str(cookie_file.as_posix())

                    load_cookies(cookie_file)
                except Exception as e:
                    err_msg = f"Failed to create cookie file for '{self.info.id}: {self.info.title}'. '{e!s}'."
                    self.logger.error(err_msg)
                    raise ValueError(err_msg) from e

            if not self.info_dict:
                self.logger.info(f"Extracting info for '{self.info.url}'.")
                self.logs = []
                ie_params = params.copy()
                ie_params["callback"] = {
                    "func": lambda _, msg: self.logs.append(msg),
                    "level": logging.WARNING,
                    "name": "callback-logger",
                }

                info = extract_info(
                    config=params,
                    url=self.info.url,
                    debug=self.debug,
                    no_archive=not params.get("download_archive", False),
                    follow_redirect=True,
                )

                if info:
                    self.info_dict = info

            if self.is_live:
                hasDeletedOptions = False
                deletedOpts: list = []
                for opt in self.bad_live_options:
                    if opt in params:
                        params.pop(opt, None)
                        hasDeletedOptions = True
                        deletedOpts.append(opt)

                if hasDeletedOptions:
                    self.logger.warning(
                        f"Live stream detected for '{self.info.title}', The following opts '{deletedOpts=}' have been deleted."
                    )

            if isinstance(self.info_dict, dict) and len(self.info_dict.get("formats", [])) < 1:
                msg = f"Failed to extract any formats for '{self.info.url}'."
                if filtered_logs := extract_ytdlp_logs(self.logs):
                    msg += f" Logs: {', '.join(filtered_logs)}"

                raise ValueError(msg)  # noqa: TRY301

            self.logger.info(
                f'Task id="{self.info.id}" PID="{os.getpid()}" title="{self.info.title}" preset="{self.preset}" cookies="{bool(params.get("cookiefile"))}" started.'
            )

            self.logger.debug(f"Params before passing to yt-dlp. {params}")

            params["logger"] = NestedLogger(self.logger)

            cls = yt_dlp.YoutubeDL(params=params)

            self.started_time = int(time.time())

            if isinstance(self.info_dict, dict) and len(self.info_dict) > 1:
                self.logger.debug(f"Downloading '{self.info.url}' using pre-info.")
                cls.process_ie_result(
                    ie_result=self.info_dict,
                    download=True,
                    extra_info={k: v for k, v in self.info.extras.items() if k not in self.info_dict},
                )
                ret = cls._download_retcode
            else:
                self.logger.debug(f"Downloading using url: {self.info.url}")
                ret = cls.download(url_list=[self.info.url])

            self.status_queue.put({"id": self.id, "status": "finished" if ret == 0 else "error"})
        except yt_dlp.utils.ExistingVideoReached as exc:
            self.logger.error(exc)
            self.status_queue.put({"id": self.id, "status": "skip", "msg": "Item has already been downloaded."})
        except Exception as exc:
            self.logger.exception(exc)
            self.logger.error(exc)
            self.status_queue.put({"id": self.id, "status": "error", "msg": str(exc), "error": str(exc)})
        finally:
            self.status_queue.put(Terminator())

        self.logger.info(f'Task id="{self.info.id}" PID="{os.getpid()}" title="{self.info.title}" completed.')

    async def start(self):
        self.status_queue = Config.get_manager().Queue()

        # Create temp dir for each download.
        self.temp_path = Path(self.temp_dir) / hashlib.shake_256(f"D-{self.info.id}".encode()).hexdigest(5)

        if not self.temp_path.exists():
            self.temp_path.mkdir(parents=True, exist_ok=True)

        self.info.temp_path = str(self.temp_path)

        self.proc = multiprocessing.Process(name=f"download-{self.id}", target=self._download)
        self.proc.start()
        self.info.status = "preparing"

        await self._notify.emit(Events.UPDATED, data=self.info)
        asyncio.create_task(self.progress_update(), name=f"update-{self.id}")

        return await asyncio.get_running_loop().run_in_executor(None, self.proc.join)

    def started(self) -> bool:
        return self.proc is not None

    def cancel(self) -> bool:
        if not self.started():
            return False

        self.cancelled = True

        return True

    async def close(self) -> bool:
        """
        Close download process.
        This method MUST be called to clear resources.
        """
        if not self.started() or self.cancel_in_progress:
            return False

        self.cancel_in_progress = True
        procId = self.proc.ident

        self.logger.info(f"Closing PID='{procId}' download process.")

        try:
            try:
                if "update_task" in self.__dict__ and self.update_task.done() is False:
                    self.update_task.cancel()
            except Exception as e:
                self.logger.error(f"Failed to close status queue: '{procId}'. {e}")

            self.kill()

            loop = asyncio.get_running_loop()

            if self.proc.is_alive():
                self.logger.debug(f"Waiting for PID='{procId}' to close.")
                await loop.run_in_executor(None, self.proc.join)
                self.logger.debug(f"PID='{procId}' closed.")

            if self.status_queue:
                self.logger.debug(f"Closing status queue for PID='{procId}'.")
                self.status_queue.put(Terminator())
                self.logger.debug(f"Closed status queue for PID='{procId}'.")

            if self.proc:
                self.proc.close()
                self.proc = None

            self.delete_temp()

            self.logger.debug(f"Closed PID='{procId}' download process.")

            return True
        except Exception as e:
            self.logger.error(f"Failed to close process: '{procId}'. {e}")

        return False

    def running(self) -> bool:
        try:
            return self.proc is not None and self.proc.is_alive()
        except ValueError:
            return False

    def is_cancelled(self) -> bool:
        return self.cancelled

    def kill(self) -> bool:
        if not self.running():
            return False

        try:
            self.logger.info(f"Killing download process: '{self.proc.ident}'.")
            self.proc.kill()
            return True
        except Exception as e:
            self.logger.error(f"Failed to kill process: '{self.proc.ident}'. {e}")

        return False

    def delete_temp(self):
        if self.temp_keep is True or not self.temp_path:
            return

        if "finished" != self.info.status and self.is_live:
            self.logger.warning(
                f"Keeping live temp folder '{self.temp_path}', as the reported status is not finished '{self.info.status}'."
            )
            return

        tmp_dir = Path(self.temp_path)

        if not tmp_dir.exists():
            return

        if str(tmp_dir) == str(self.temp_dir):
            self.logger.warning(
                f"Attempted to delete video temp folder '{self.temp_path}', but it is the same as main temp folder."
            )
            return

        status = delete_dir(tmp_dir)
        self.logger.info(f"Temp folder '{self.temp_path}' deletion is {'success' if status else 'failed'}.")

    async def progress_update(self):
        """
        Update status of download task and notify the client.
        """
        while True:
            try:
                self.update_task = asyncio.get_running_loop().run_in_executor(None, self.status_queue.get)
                status = await self.update_task
            except (asyncio.CancelledError, OSError, FileNotFoundError):
                return

            if status is None or isinstance(status, Terminator):
                return

            if status.get("id") != self.id or len(status) < 2:
                continue

            if self.debug:
                self.logger.debug(f"Status Update: {self.info._id=} {status=}")

            if isinstance(status, str):
                await self._notify.emit(Events.UPDATED, data=self.info)
                continue

            self.tmpfilename = status.get("tmpfilename")

            if "filename" in status:
                fl = Path(status.get("filename"))
                try:
                    self.info.filename = str(Path(status.get("filename")).relative_to(Path(self.download_dir)))
                except ValueError:
                    self.info.filename = str(Path(status.get("filename")).relative_to(Path(self.temp_path)))

                if fl.is_file() and fl.exists():
                    try:
                        self.info.file_size = fl.stat().st_size
                    except FileNotFoundError:
                        self.info.file_size = 0

            self.info.status = status.get("status", self.info.status)
            self.info.msg = status.get("msg")

            if "error" == self.info.status and "error" in status:
                self.info.error = status.get("error")
                await self._notify.emit(Events.ERROR, data={"message": self.info.error, "data": self.info})

            if "downloaded_bytes" in status and status.get("downloaded_bytes") > 0:
                self.info.downloaded_bytes = status.get("downloaded_bytes")
                total = status.get("total_bytes") or status.get("total_bytes_estimate")
                if total:
                    try:
                        self.info.percent = status["downloaded_bytes"] / total * 100
                    except ZeroDivisionError:
                        self.info.percent = 0
                    self.info.total_bytes = total

            self.info.speed = status.get("speed")
            self.info.eta = status.get("eta")

            fl = Path(status.get("filename")) if status and "filename" in status else None

            if "finished" == self.info.status and fl and fl.is_file() and fl.exists():
                self.info.file_size = fl.stat().st_size
                self.info.datetime = str(formatdate(time.time()))

                try:
                    ff = await ffprobe(status.get("filename"))
                    self.info.extras["is_video"] = ff.has_video()
                    self.info.extras["is_audio"] = ff.has_audio()
                    if (ff.has_video() or ff.has_audio()) and not self.info.extras.get("duration"):
                        self.info.extras["duration"] = int(float(ff.metadata.get("duration", 0.0)))
                except Exception as e:
                    self.info.extras["is_video"] = True
                    self.info.extras["is_audio"] = True
                    self.logger.exception(e)
                    self.logger.error(f"Failed to run ffprobe. {status.get}. {e}")

            await self._notify.emit(Events.UPDATED, data=self.info)

    def is_stale(self) -> bool:
        """
        Check if the download task is stale.
        A download task is considered stale if it has not been updated for a certain period of time.

        Returns:
            bool: True if the download task is stale, False otherwise.

        """
        if self.started_time < 1:
            self.logger.debug(f"Download task '{self.info.title}: {self.info.id}' not started yet.")
            return False

        if int(time.time()) - self.started_time < 300:
            self.logger.debug(
                f"Download task '{self.info.title}: {self.info.id}' started for '{int(time.time()) - self.started_time}' seconds."
            )
            return False

        if not self.running():
            self.logger.warning(
                f"Download task '{self.info.title}: {self.info.id}' not started running for '{int(time.time()) - self.started_time}' seconds."
            )
            return True

        if self.info.status not in ["finished", "error", "cancelled", "downloading", "postprocessing"]:
            status = self.info.status if self.info.status else "unknown"
            self.logger.warning(
                f"Download task '{self.info.title}: {self.info.id}' has been stuck in '{status}' state for '{int(time.time()) - self.started_time}' seconds."
            )
            return True

        return False