"""
download.py

Implements the Download class and helpers for downloading media from TIDAL, including segment merging, file moving, metadata writing, and playlist creation.

Classes:
    RequestsClient: Simple HTTP client for downloading text content.
    Download: Main class for managing downloads, segment merging, file operations, and metadata.
"""

import os
import pathlib
import random
import shutil
import tempfile
import time
from collections.abc import Callable
from concurrent import futures
from threading import Event
from uuid import uuid4

import m3u8
import requests
from ffmpeg import FFmpeg
from pathvalidate import sanitize_filename
from requests.adapters import HTTPAdapter, Retry
from requests.exceptions import HTTPError
from rich.progress import Progress, TaskID
from tidalapi import Album, Mix, Playlist, Session, Track, UserPlaylist, Video
from tidalapi.exceptions import TooManyRequests
from tidalapi.media import (
    AudioExtensions,
    AudioMode,
    Codec,
    Quality,
    Stream,
    StreamManifest,
    VideoExtensions,
)

from tidal_dl_ng.config import Settings, Tidal
from tidal_dl_ng.constants import (
    CHUNK_SIZE,
    COVER_NAME,
    EXTENSION_LYRICS,
    METADATA_EXPLICIT,
    METADATA_LOOKUP_UPC,
    PLAYLIST_EXTENSION,
    PLAYLIST_PREFIX,
    REQUESTS_TIMEOUT_SEC,
    AudioExtensionsValid,
    CoverDimensions,
    MediaType,
    MetadataTargetUPC,
    QualityVideo,
)
from tidal_dl_ng.helper.decryption import decrypt_file, decrypt_security_token
from tidal_dl_ng.helper.exceptions import MediaMissing
from tidal_dl_ng.helper.path import (
    check_file_exists,
    format_path_media,
    path_file_sanitize,
    url_to_filename,
)
from tidal_dl_ng.helper.tidal import (
    instantiate_media,
    items_results_all,
    name_builder_album_artist,
    name_builder_artist,
    name_builder_item,
    name_builder_title,
)
from tidal_dl_ng.metadata import Metadata
from tidal_dl_ng.model.downloader import DownloadSegmentResult, TrackStreamInfo
from tidal_dl_ng.model.gui_data import ProgressBars


# TODO: Set appropriate client string and use it for video download.
# https://github.com/globocom/m3u8#using-different-http-clients
class RequestsClient:
    """HTTP client for downloading text content from a URI."""

    def download(
        self, uri: str, timeout: int = REQUESTS_TIMEOUT_SEC, headers: dict | None = None, verify_ssl: bool = True
    ) -> tuple[str, str]:
        """Download the content of a URI as text.

        Args:
            uri (str): The URI to download.
            timeout (int, optional): Timeout in seconds. Defaults to REQUESTS_TIMEOUT_SEC.
            headers (dict | None, optional): HTTP headers. Defaults to None.
            verify_ssl (bool, optional): Whether to verify SSL. Defaults to True.

        Returns:
            tuple[str, str]: Tuple of (text content, final URL).
        """
        if not headers:
            headers = {}

        o = requests.get(uri, timeout=timeout, headers=headers)
        o.raise_for_status()

        return o.text, o.url


# TODO: Use pathlib.Path everywhere
class Download:
    """Main class for managing downloads, segment merging, file operations, and metadata for TIDAL media."""

    settings: Settings
    tidal: "Tidal"
    session: Session
    skip_existing: bool = False
    fn_logger: Callable
    progress_gui: ProgressBars
    progress: Progress
    progress_overall: Progress
    event_abort: Event
    event_run: Event

    def __init__(
        self,
        tidal_obj: Tidal,  # Required for Atmos session context manager
        path_base: str,
        fn_logger: Callable,
        skip_existing: bool = False,
        progress_gui: ProgressBars | None = None,
        progress: Progress | None = None,
        progress_overall: Progress | None = None,
        event_abort: Event | None = None,
        event_run: Event | None = None,
    ) -> None:
        """Initialize the Download object and its dependencies.

        Args:
            tidal_obj (Tidal): TIDAL configuration object. Required for:
                - session: Main TIDAL API session
                - switch_to_atmos_session(): Dolby Atmos credential switching
                - restore_normal_session(): Restore original session credentials
            path_base (str): Base path for downloads.
            fn_logger (Callable): Logger function or object.
            skip_existing (bool, optional): Whether to skip existing files. Defaults to False.
            progress_gui (ProgressBars | None, optional): GUI progress bars. Defaults to None.
            progress (Progress | None, optional): Rich progress bar. Defaults to None.
            progress_overall (Progress | None, optional): Overall progress bar. Defaults to None.
            event_abort (Event | None, optional): Abort event. Defaults to None.
            event_run (Event | None, optional): Run event. Defaults to None.
        """
        self.settings = Settings()
        self.tidal = tidal_obj
        self.session = tidal_obj.session
        self.skip_existing = skip_existing
        self.fn_logger = fn_logger
        self.progress_gui = progress_gui
        self.progress = progress
        self.progress_overall = progress_overall
        self.path_base = path_base
        self.event_abort = event_abort
        self.event_run = event_run

        if not self.settings.data.path_binary_ffmpeg and (
            self.settings.data.video_convert_mp4 or self.settings.data.extract_flac
        ):
            self.settings.data.video_convert_mp4 = False
            self.settings.data.extract_flac = False

            self.fn_logger.error(
                "FFmpeg path is not set. Videos can be downloaded but will not be processed. FLAC cannot be "
                "extracted from MP4 containers. Make sure FFmpeg is installed. The path to the FFmpeg binary must "
                "be set in (`path_binary_ffmpeg`)."
            )

    def _get_media_urls(
        self,
        media: Track | Video,
        stream_manifest: StreamManifest | None = None,
    ) -> list[str]:
        """Extract URLs for the given media item.

        Args:
            media (Track | Video): The media item to download.
            stream_manifest (StreamManifest | None, optional): Stream manifest for tracks. Defaults to None.

        Returns:
            list[str]: List of URLs for the media segments.
        """
        # Get urls for media.
        if isinstance(media, Track):
            return stream_manifest.get_urls()
        elif isinstance(media, Video):
            quality_video = self.settings.data.quality_video
            m3u8_variant: m3u8.M3U8 = m3u8.load(media.get_url())
            # Find the desired video resolution or the next best one.
            m3u8_playlist, _ = self._extract_video_stream(m3u8_variant, int(quality_video))

            return m3u8_playlist.files
        else:
            return []

    def _setup_progress(
        self,
        media_name: str,
        urls: list[str],
        progress_to_stdout: bool,
    ) -> tuple[TaskID, int | float | None, int | None]:
        """Set up the progress bar/task and compute progress total and block size.

        Args:
            media_name (str): Name of the media item.
            urls (list[str]): List of segment URLs.
            progress_to_stdout (bool): Whether to show progress in stdout.

        Returns:
            tuple[TaskID, int | float | None, int | None]: (TaskID, progress_total, block_size)
        """
        urls_count: int = len(urls)
        progress_total: int | float | None = None
        block_size: int | None = None

        # Compute total iterations for progress
        if urls_count > 1:
            progress_total: int = urls_count
            block_size: int | None = None
        elif urls_count == 1:
            r = None
            try:
                # Get file size and compute progress steps
                r = requests.head(urls[0], timeout=REQUESTS_TIMEOUT_SEC)
                r.raise_for_status()

                total_size_in_bytes: int = int(r.headers.get("content-length", 0))
                block_size = 1048576
                progress_total = total_size_in_bytes / block_size
            finally:
                if r:
                    r.close()
        else:
            raise ValueError

        # Create progress Task
        p_task: TaskID = self.progress.add_task(
            f"[blue]Item '{media_name[:30]}'",
            total=progress_total,
            visible=progress_to_stdout,
        )
        return p_task, progress_total, block_size

    def _download_segments(
        self,
        urls: list[str],
        path_base: pathlib.Path,
        block_size: int | None,
        p_task: TaskID,
        progress_to_stdout: bool,
    ) -> tuple[bool, list[DownloadSegmentResult]]:
        """Download all segments with progress reporting and abort handling.

        Args:
            urls (list[str]): List of segment URLs.
            path_base (pathlib.Path): Base path for segment files.
            block_size (int | None): Block size for streaming.
            p_task (TaskID): Progress bar task ID.
            progress_to_stdout (bool): Whether to show progress in stdout.

        Returns:
            tuple[bool, list[DownloadSegmentResult]]: (result_segments, list of segment results)
        """
        result_segments: bool = True
        dl_segment_results: list[DownloadSegmentResult] = []

        # Download segments until progress is finished.
        # TODO: Compute download speed (https://github.com/Textualize/rich/blob/master/examples/downloader.py)
        while not self.progress.tasks[p_task].finished:
            with futures.ThreadPoolExecutor(
                max_workers=self.settings.data.downloads_simultaneous_per_track_max
            ) as executor:
                # Dispatch all download tasks to worker threads
                l_futures: list[futures.Future] = [
                    executor.submit(self._download_segment, url, path_base, block_size, p_task, progress_to_stdout)
                    for url in urls
                ]

                # Report results as they become available
                for future in futures.as_completed(l_futures):
                    # Retrieve result
                    result_dl_segment: DownloadSegmentResult = future.result()

                    dl_segment_results.append(result_dl_segment)

                    # Check for a link that was skipped
                    if not result_dl_segment.result and (result_dl_segment.url is not urls[-1]):
                        # Sometimes it happens, if a track is very short (< 8 seconds or so), that the last URL in `urls` is
                        # invalid (HTTP Error 500) and not necessary. File won't be corrupt.
                        # If this is NOT the case, but any other URL has resulted in an error,
                        # mark the whole thing as corrupt.
                        result_segments = False

                        self.fn_logger.error("Something went wrong while downloading. File is corrupt!")

                    # If app is terminated (CTRL+C)
                    if self.event_abort.is_set():
                        # Cancel all not yet started tasks
                        for f in l_futures:
                            f.cancel()

                        return False, dl_segment_results

        return result_segments, dl_segment_results

    def _download_postprocess(
        self,
        result_segments: bool,
        path_file: pathlib.Path,
        dl_segment_results: list[DownloadSegmentResult],
        media: Track | Video,
        stream_manifest: StreamManifest | None = None,
    ) -> tuple[bool, pathlib.Path]:
        """Merge segments, decrypt if needed, and return the final file path.

        Args:
            result_segments (bool): Whether all segments downloaded successfully.
            path_file (pathlib.Path): Path to the output file.
            dl_segment_results (list[DownloadSegmentResult]): List of segment download results.
            media (Track | Video): The media item.
            stream_manifest (StreamManifest | None, optional): Stream manifest for tracks. Defaults to None.

        Returns:
            tuple[bool, pathlib.Path]: (Success, path to downloaded or decrypted file)
        """
        tmp_path_file_decrypted: pathlib.Path = path_file
        result_merge: bool = False

        # Only if no error happened while downloading.
        if result_segments:
            # Bring list into right order, so segments can be easily merged.
            dl_segment_results.sort(key=lambda x: x.id_segment)

            result_merge = self._segments_merge(path_file, dl_segment_results)

            if not result_merge:
                self.fn_logger.error(f"Something went wrong while writing to {media.name}. File is corrupt!")
            elif isinstance(media, Track) and stream_manifest.is_encrypted:
                key, nonce = decrypt_security_token(stream_manifest.encryption_key)
                tmp_path_file_decrypted = path_file.with_suffix(".decrypted")

                decrypt_file(path_file, tmp_path_file_decrypted, key, nonce)

        return result_merge, tmp_path_file_decrypted

    def _download(
        self,
        media: Track | Video,
        path_file: pathlib.Path,
        stream_manifest: StreamManifest | None = None,
    ) -> tuple[bool, pathlib.Path]:
        """Download a media item (track or video), handling segments and merging.

        Args:
            media (Track | Video): The media item to download.
            path_file (pathlib.Path): Path to the output file.
            stream_manifest (StreamManifest | None, optional): Stream manifest for tracks. Defaults to None.

        Returns:
            tuple[bool, pathlib.Path]: (Success, path to downloaded or decrypted file)
        """
        media_name: str = name_builder_item(media)

        try:
            urls: list[str] = self._get_media_urls(media, stream_manifest)
        except Exception:
            return False, path_file

        # Set the correct progress output channel.
        if self.progress_gui is None:
            progress_to_stdout: bool = True
        else:
            progress_to_stdout: bool = False
            # Send signal to GUI with media name
            self.progress_gui.item_name.emit(media_name[:30])

        try:
            p_task, progress_total, block_size = self._setup_progress(media_name, urls, progress_to_stdout)
        except Exception:
            return False, path_file

        result_segments, dl_segment_results = self._download_segments(
            urls, path_file.parent, block_size, p_task, progress_to_stdout
        )

        result_merge, tmp_path_file_decrypted = self._download_postprocess(
            result_segments, path_file, dl_segment_results, media, stream_manifest
        )

        return result_merge, tmp_path_file_decrypted

    def _segments_merge(self, path_file: pathlib.Path, dl_segment_results: list[DownloadSegmentResult]) -> bool:
        """Merge downloaded segments into a single file and clean up segment files.

        Args:
            path_file (pathlib.Path): Path to the output file.
            dl_segment_results (list[DownloadSegmentResult]): List of segment download results.

        Returns:
            bool: True if merge succeeded, False otherwise.
        """
        result: bool = True

        # Copy the content of all segments into one file.
        try:
            with path_file.open("wb") as f_target:
                for dl_segment_result in dl_segment_results:
                    with dl_segment_result.path_segment.open("rb") as f_segment:
                        # Read and write chunks, which gives better HDD write performance
                        while segment := f_segment.read(CHUNK_SIZE):
                            f_target.write(segment)

                    # Delete segment from HDD
                    dl_segment_result.path_segment.unlink()

        except Exception:
            if dl_segment_result is not dl_segment_results[-1]:
                result = False

        return result

    def _download_segment(
        self, url: str, path_base: pathlib.Path, block_size: int | None, p_task: TaskID, progress_to_stdout: bool
    ) -> DownloadSegmentResult:
        """Download a single segment of a media file.

        Args:
            url (str): URL of the segment.
            path_base (pathlib.Path): Base path for segment file.
            block_size (int | None): Block size for streaming.
            p_task (TaskID): Progress bar task ID.
            progress_to_stdout (bool): Whether to show progress in stdout.

        Returns:
            DownloadSegmentResult: Result of the segment download.
        """
        result: bool = False
        path_segment: pathlib.Path = path_base / url_to_filename(url)
        # Calculate the segment ID based on the file name within the URL.
        filename_stem: str = str(path_segment.stem).split("_")[-1]
        # CAUTION: This is a workaround, so BTS (LOW quality) track will work. They usually have only ONE link.
        id_segment: int = int(filename_stem) if filename_stem.isdecimal() else 0
        error: HTTPError | None = None

        # If app is terminated (CTRL+C)
        if self.event_abort.is_set():
            return DownloadSegmentResult(
                result=False, url=url, path_segment=path_segment, id_segment=id_segment, error=error
            )

        if not self.event_run.is_set():
            self.event_run.wait()

        # Retry download on failed segments, with an exponential delay between retries
        with requests.Session() as s:
            retries = Retry(total=5, backoff_factor=1)  # , status_forcelist=[ 502, 503, 504 ])

            s.mount("https://", HTTPAdapter(max_retries=retries))

            try:
                # Create the request object with stream=True, so the content won't be loaded into memory at once.
                r = s.get(url, stream=True, timeout=REQUESTS_TIMEOUT_SEC)

                r.raise_for_status()

                # Write the content to disk. If `chunk_size` is set to `None` the whole file will be written at once.
                with path_segment.open("wb") as f:
                    for data in r.iter_content(chunk_size=block_size):
                        f.write(data)
                        # Advance progress bar.
                        self.progress.advance(p_task)

                result = True
            except Exception:
                self.progress.advance(p_task)

        # To send the progress to the GUI, we need to emit the percentage.
        if not progress_to_stdout:
            self.progress_gui.item.emit(self.progress.tasks[p_task].percentage)

        return DownloadSegmentResult(
            result=result, url=url, path_segment=path_segment, id_segment=id_segment, error=error
        )

    def extension_guess(
        self, quality_audio: Quality, metadata_tags: list[str], is_video: bool
    ) -> AudioExtensions | VideoExtensions:
        """Guess the file extension for a media item based on quality and type.

        Args:
            quality_audio (Quality): Audio quality.
            metadata_tags (list[str]): Metadata tags for the media.
            is_video (bool): Whether the media is a video.

        Returns:
            AudioExtensions | VideoExtensions: Guessed file extension.
        """
        result: AudioExtensions | VideoExtensions

        if is_video:
            result = AudioExtensions.MP4 if self.settings.data.video_convert_mp4 else VideoExtensions.TS
        else:
            result = (
                AudioExtensions.FLAC
                if len(metadata_tags) > 0  # If there are no metadata tags only lossy quality is available
                and (
                    (
                        self.settings.data.extract_flac
                        and quality_audio in (Quality.hi_res_lossless, Quality.high_lossless)
                    )
                    or (
                        "HIRES_LOSSLESS" not in metadata_tags
                        and quality_audio not in (Quality.low_96k, Quality.low_320k)
                    )
                    or quality_audio == Quality.high_lossless
                )
                else AudioExtensions.M4A
            )

        return result

    def item(
        self,
        file_template: str,
        media_id: str | None = None,
        media_type: MediaType | None = None,
        media: Track | Video | None = None,
        video_download: bool = True,
        download_delay: bool = False,
        quality_audio: Quality | None = None,
        quality_video: QualityVideo | None = None,
        is_parent_album: bool = False,
        list_position: int = 0,
        list_total: int = 0,
    ) -> tuple[bool, pathlib.Path | str]:
        """Download a single media item, handling file naming, skipping, and post-processing.

        Args:
            file_template (str): Template for file naming.
            media_id (str | None, optional): Media ID. Defaults to None.
            media_type (MediaType | None, optional): Media type. Defaults to None.
            media (Track | Video | None, optional): Media item. Defaults to None.
            video_download (bool, optional): Whether to allow video downloads. Defaults to True.
            download_delay (bool, optional): Whether to delay between downloads. Defaults to False.
            quality_audio (Quality | None, optional): Audio quality. Defaults to None.
            quality_video (QualityVideo | None, optional): Video quality. Defaults to None.
            is_parent_album (bool, optional): Whether this is a parent album. Defaults to False.
            list_position (int, optional): Position in list. Defaults to 0.
            list_total (int, optional): Total items in list. Defaults to 0.

        Returns:
            tuple[bool, pathlib.Path | str]: (Downloaded, path to file)
        """
        # Step 1: Validate and prepare media
        validated_media = self._validate_and_prepare_media(media, media_id, media_type, video_download)
        if validated_media is None or not isinstance(validated_media, Track | Video):
            return False, ""

        media = validated_media

        # Step 2: Create file paths and determine skip logic
        path_media_dst, file_extension_dummy, skip_file, skip_download = self._prepare_file_paths_and_skip_logic(
            media, file_template, quality_audio, list_position, list_total
        )

        if skip_file:
            self.fn_logger.debug(f"Download skipped, since file exists: '{path_media_dst}'")

            return True, path_media_dst

        # Step 3: Handle quality settings
        quality_audio_old, quality_video_old = self._adjust_quality_settings(quality_audio, quality_video)

        # Step 4: Download and process media
        download_success = self._download_and_process_media(
            media, path_media_dst, skip_download, is_parent_album, file_extension_dummy
        )

        # Step 5: Post-processing
        self._perform_post_processing(
            media,
            path_media_dst,
            quality_audio,
            quality_video,
            quality_audio_old,
            quality_video_old,
            download_delay,
            skip_file,
        )

        return download_success, path_media_dst

    def _validate_and_prepare_media(
        self,
        media: Track | Video | Album | Playlist | UserPlaylist | Mix | None,
        media_id: str | None,
        media_type: MediaType | None,
        video_download: bool = True,
    ) -> Track | Video | Album | Playlist | UserPlaylist | Mix | None:
        """Validate and prepare media instance for download.

        Args:
            media (Track | Video | Album | Playlist | UserPlaylist | Mix | None): Media instance.
            media_id (str | None): Media ID if creating new instance.
            media_type (MediaType | None): Media type if creating new instance.
            video_download (bool, optional): Whether video downloads are allowed. Defaults to True.

        Returns:
            Track | Video | Album | Playlist | UserPlaylist | Mix | None: Prepared media instance or None if invalid.
        """
        try:
            if media_id and media_type:
                # If no media instance is provided, we need to create the media instance.
                # Throws `tidalapi.exceptions.ObjectNotFound` if item is not available anymore.
                media = instantiate_media(self.session, media_type, media_id)
            elif isinstance(media, Track | Video):
                # Check if media is available not deactivated / removed from TIDAL.
                if not media.available:
                    self.fn_logger.info(
                        f"This item is not available for listening anymore on TIDAL. Skipping: {name_builder_item(media)}"
                    )
                    return None
                elif isinstance(media, Track):
                    # Re-create media instance with full album information
                    media = self.session.track(str(media.id), with_album=True)
            elif isinstance(media, Album):
                # Check if media is available not deactivated / removed from TIDAL.
                if not media.available:
                    self.fn_logger.info(
                        f"This item is not available for listening anymore on TIDAL. Skipping: {name_builder_title(media)}"
                    )
                    return None
            elif not media:
                self._raise_media_missing()
        except (MediaMissing, Exception):
            return None

        # If video download is not allowed and this is a video, return None
        if not video_download and isinstance(media, Video):
            self.fn_logger.info(
                f"Video downloads are deactivated (see settings). Skipping video: {name_builder_item(media)}"
            )
            return None

        return media

    def _raise_media_missing(self) -> None:
        """Raise MediaMissing exception.

        Helper method to abstract raise statement as per TRY301.
        """
        raise MediaMissing

    def _prepare_file_paths_and_skip_logic(
        self,
        media: Track | Video,
        file_template: str,
        quality_audio: Quality | None,
        list_position: int,
        list_total: int,
    ) -> tuple[pathlib.Path, str, bool, bool]:
        """Prepare file paths and determine skip logic.

        Args:
            media (Track | Video): Media item.
            file_template (str): Template for file naming.
            quality_audio (Quality | None): Audio quality setting.
            list_position (int): Position in list.
            list_total (int): Total items in list.

        Returns:
            tuple[pathlib.Path, str, bool, bool]: (path_media_dst, file_extension_dummy, skip_file, skip_download)
        """
        # Create file name and path
        metadata_tags = [] if isinstance(media, Video) else (media.media_metadata_tags or [])
        quality_for_extension = quality_audio if quality_audio is not None else Quality.high_lossless

        file_extension_dummy: str = self.extension_guess(
            quality_for_extension,
            metadata_tags=metadata_tags,
            is_video=isinstance(media, Video),
        )

        file_name_relative: str = format_path_media(
            file_template,
            media,
            self.settings.data.album_track_num_pad_min,
            list_position,
            list_total,
            delimiter_artist=self.settings.data.filename_delimiter_artist,
            delimiter_album_artist=self.settings.data.filename_delimiter_album_artist,
            use_primary_album_artist=self.settings.data.use_primary_album_artist,
        )

        path_media_dst: pathlib.Path = (
            pathlib.Path(self.path_base).expanduser() / (file_name_relative + file_extension_dummy)
        ).absolute()

        # Sanitize final path_file to fit into OS boundaries.
        path_media_dst = pathlib.Path(path_file_sanitize(path_media_dst, adapt=True))

        # Compute if and how downloads need to be skipped.
        skip_download: bool = False

        if self.skip_existing:
            skip_file: bool = check_file_exists(path_media_dst, extension_ignore=False)

            if self.settings.data.symlink_to_track and not isinstance(media, Video):
                # Compute symlink tracks path, sanitize and check if file exists
                file_name_track_dir_relative: str = format_path_media(
                    self.settings.data.format_track,
                    media,
                    delimiter_artist=self.settings.data.filename_delimiter_artist,
                    delimiter_album_artist=self.settings.data.filename_delimiter_album_artist,
                    use_primary_album_artist=self.settings.data.use_primary_album_artist,
                )
                path_media_track_dir: pathlib.Path = (
                    pathlib.Path(self.path_base).expanduser() / (file_name_track_dir_relative + file_extension_dummy)
                ).absolute()
                path_media_track_dir = pathlib.Path(path_file_sanitize(path_media_track_dir, adapt=True))
                file_exists_track_dir: bool = check_file_exists(path_media_track_dir, extension_ignore=False)
                file_exists_playlist_dir: bool = (
                    not file_exists_track_dir and skip_file and not path_media_dst.is_symlink()
                )
                skip_download = file_exists_playlist_dir or file_exists_track_dir

                # If file exists in playlist dir but not in track dir, we don't skip the file itself
                if skip_file and file_exists_playlist_dir:
                    skip_file = False
        else:
            skip_file: bool = False

        return path_media_dst, file_extension_dummy, skip_file, skip_download

    def _adjust_quality_settings(
        self, quality_audio: Quality | None, quality_video: QualityVideo | None
    ) -> tuple[Quality | None, QualityVideo | None]:
        """Adjust quality settings and return previous values.

        Args:
            quality_audio (Quality | None): Audio quality setting.
            quality_video (QualityVideo | None): Video quality setting.

        Returns:
            tuple[Quality | None, QualityVideo | None]: Previous quality settings.
        """
        quality_audio_old: Quality | None = None
        quality_video_old: QualityVideo | None = None

        if quality_audio:
            quality_audio_old = self.adjust_quality_audio(quality_audio)

        if quality_video:
            quality_video_old = self.adjust_quality_video(quality_video)

        return quality_audio_old, quality_video_old

    def _download_and_process_media(
        self,
        media: Track | Video,
        path_media_dst: pathlib.Path,
        skip_download: bool,
        is_parent_album: bool,
        file_extension_dummy: str,
    ) -> bool:
        """Download and process media file.

        Args:
            media (Track | Video): Media item.
            path_media_dst (pathlib.Path): Destination file path.
            skip_download (bool): Whether to skip download.
            is_parent_album (bool): Whether this is a parent album.
            file_extension_dummy (str): Dummy file extension.

        Returns:
            bool: Whether download was successful.
        """
        if skip_download:
            return True

        # Get stream information and final file extension
        stream_manifest, file_extension, do_flac_extract, media_stream = self._get_stream_info(media)

        if stream_manifest is None and isinstance(media, Track):
            return False

        # Update path if extension changed
        if path_media_dst.suffix != file_extension:
            path_media_dst = path_media_dst.with_suffix(file_extension)
            path_media_dst = pathlib.Path(path_file_sanitize(path_media_dst, adapt=True))

        os.makedirs(path_media_dst.parent, exist_ok=True)

        # Perform actual download
        return self._perform_actual_download(
            media, path_media_dst, stream_manifest, do_flac_extract, is_parent_album, media_stream
        )

    def _get_stream_info(self, media: Track | Video) -> tuple[StreamManifest | None, str, bool, Stream | None]:
        """Get stream information for media.

        Args:
            media (Track | Video): Media item.

        Returns:
        tuple[StreamManifest | None, str, bool, Stream | None]: Stream info.
        """
        stream_manifest: StreamManifest | None = None
        media_stream: Stream | None = None
        do_flac_extract: bool = False
        file_extension: str = ""

        # CRITICAL: This lock is intentionally broad and serializes all
        # stream-fetching (Phase 1) to prevent a critical race condition.
        #
        # THE PROBLEM:
        # The single, shared session (self.tidal.session) must change its
        # credentials to switch between Atmos and Hi-Res/Normal streams.
        #
        # THE RACE CONDITION IT FIXES:
        # If this lock is released *before* get_stream() is called,
        # another thread could change the session (e.g., back to "Normal")
        # right after this thread switched it to "Atmos". This would
        # cause this thread to call get_stream() with the wrong credentials,
        # resulting in the API returning AAC 320 instead of Atmos.
        #
        # THE TRADEOFF:
        # This creates a "tollbooth" bottleneck, serializing the get_stream()
        # calls. However, the *actual* segment downloads (Phase 2)
        # still run in parallel, governed by `downloads_concurrent_max`.
        #
        # DO NOT "OPTIMIZE" THIS by making the lock more granular.
        # Correctness > Performance.

        with self.tidal.stream_lock:
            try:
                if isinstance(media, Track):
                    track_info = self._get_track_stream_info(media)

                    if track_info.stream_manifest is None:
                        return None, "", False, None

                    stream_manifest = track_info.stream_manifest
                    file_extension = track_info.file_extension
                    do_flac_extract = track_info.requires_flac_extraction
                    media_stream = track_info.media_stream

                elif isinstance(media, Video):
                    # Videos always require the normal session
                    if not self.tidal.restore_normal_session():
                        self.fn_logger.error(f"Failed to restore normal session for video: {media.id}")
                        return None, "", False, None

                    file_extension = AudioExtensions.MP4 if self.settings.data.video_convert_mp4 else VideoExtensions.TS

                    stream_manifest = None
                    media_stream = None
                    do_flac_extract = False

                else:
                    self.fn_logger.error(f"Unknown media type for stream info: {type(media)}")
                    return None, "", False, None

            except TooManyRequests:
                self.fn_logger.exception(
                    f"Too many requests against TIDAL backend. Skipping '{name_builder_item(media)}'. "
                    f"Consider to activate delay between downloads."
                )
                return None, "", False, None

            except Exception:
                self.fn_logger.exception(f"Something went wrong. Skipping '{name_builder_item(media)}'.")
                return None, "", False, None

        return stream_manifest, file_extension, do_flac_extract, media_stream

    def _get_track_stream_info(self, media: Track) -> TrackStreamInfo:
        """
        Gets stream info for a Track, handling Atmos/Normal session switching.

        Args:
            media: The track to get stream information for.

        Returns:
            TrackStreamInfo: Container with stream manifest, file extension,
                            FLAC extraction flag, and media stream object.
                            Returns TrackStreamInfo with None/empty values if fails.
        """
        want_atmos = (
            self.settings.data.download_dolby_atmos
            and hasattr(media, "audio_modes")
            and AudioMode.dolby_atmos.value in media.audio_modes
        )

        if want_atmos:
            if not self.tidal.switch_to_atmos_session():
                self.fn_logger.error(f"Failed to switch to Atmos session for track: {media.id}")
                return TrackStreamInfo(None, "", False, None)
        else:
            if not self.tidal.restore_normal_session():
                self.fn_logger.error(f"Failed to restore normal session for track: {media.id}")
                return TrackStreamInfo(None, "", False, None)

        media_stream = self.session.track(media.id).get_stream() if want_atmos else media.get_stream()

        stream_manifest = media_stream.get_stream_manifest()
        file_extension = stream_manifest.file_extension
        requires_flac_extraction = False

        if self.settings.data.extract_flac and (
            stream_manifest.codecs.upper() == Codec.FLAC and file_extension != AudioExtensions.FLAC
        ):
            file_extension = AudioExtensions.FLAC
            requires_flac_extraction = True

        return TrackStreamInfo(
            stream_manifest=stream_manifest,
            file_extension=file_extension,
            requires_flac_extraction=requires_flac_extraction,
            media_stream=media_stream,
        )

    def _perform_actual_download(
        self,
        media: Track | Video,
        path_media_dst: pathlib.Path,
        stream_manifest: StreamManifest | None,
        do_flac_extract: bool,
        is_parent_album: bool,
        media_stream: Stream | None,
    ) -> bool:
        """Perform the actual download and processing.

        Args:
            media (Track | Video): Media item.
            path_media_dst (pathlib.Path): Destination file path.
            stream_manifest (StreamManifest | None): Stream manifest.
            do_flac_extract (bool): Whether to extract FLAC.
            is_parent_album (bool): Whether this is a parent album.
            media_stream (Stream | None): Media stream.

        Returns:
            bool: Whether download was successful.
        """
        # Create a temp directory and file.
        with tempfile.TemporaryDirectory(ignore_cleanup_errors=True) as tmp_path_dir:
            tmp_path_file: pathlib.Path = pathlib.Path(tmp_path_dir) / str(uuid4())
            tmp_path_file.touch()

            # Download media.
            result_download, tmp_path_file = self._download(
                media=media, stream_manifest=stream_manifest, path_file=tmp_path_file
            )

            if not result_download:
                return False

            # Convert video from TS to MP4
            if isinstance(media, Video) and self.settings.data.video_convert_mp4:
                tmp_path_file = self._video_convert(tmp_path_file)

            # Extract FLAC from MP4 container using ffmpeg
            if isinstance(media, Track) and self.settings.data.extract_flac and do_flac_extract:
                tmp_path_file = self._extract_flac(tmp_path_file)

            # Handle metadata, lyrics, and cover
            self._handle_metadata_and_extras(media, tmp_path_file, path_media_dst, is_parent_album, media_stream)

            self.fn_logger.info(f"Downloaded item '{name_builder_item(media)}'.")

            # Move final file to the configured destination directory.
            shutil.move(tmp_path_file, path_media_dst)

            return True

    def _handle_metadata_and_extras(
        self,
        media: Track | Video,
        tmp_path_file: pathlib.Path,
        path_media_dst: pathlib.Path,
        is_parent_album: bool,
        media_stream: Stream | None,
    ) -> None:
        """Handle metadata, lyrics, and cover processing.

        Args:
            media (Track | Video): Media item.
            tmp_path_file (pathlib.Path): Temporary file path.
            path_media_dst (pathlib.Path): Destination file path.
            is_parent_album (bool): Whether this is a parent album.
            media_stream (Stream | None): Media stream.
        """
        if isinstance(media, Video):
            return

        tmp_path_lyrics: pathlib.Path | None = None
        tmp_path_cover: pathlib.Path | None = None

        # Write metadata to file.
        if media_stream:
            result_metadata, tmp_path_lyrics, tmp_path_cover = self.metadata_write(
                media, tmp_path_file, is_parent_album, media_stream
            )

        # Move lyrics file
        if self.settings.data.lyrics_file and tmp_path_lyrics:
            self._move_lyrics(tmp_path_lyrics, path_media_dst)

        # Move cover file
        if self.settings.data.cover_album_file and tmp_path_cover:
            self._move_cover(tmp_path_cover, path_media_dst)

    def _perform_post_processing(
        self,
        media: Track | Video,
        path_media_dst: pathlib.Path,
        quality_audio: Quality | None,
        quality_video: QualityVideo | None,
        quality_audio_old: Quality | None,
        quality_video_old: QualityVideo | None,
        download_delay: bool,
        skip_file: bool,
    ) -> None:
        """Perform post-processing tasks.

        Args:
            media (Track | Video): Media item.
            path_media_dst (pathlib.Path): Destination file path.
            quality_audio (Quality | None): Audio quality setting.
            quality_video (QualityVideo | None): Video quality setting.
            quality_audio_old (Quality | None): Previous audio quality.
            quality_video_old (QualityVideo | None): Previous video quality.
            download_delay (bool): Whether to apply download delay.
            skip_file (bool): Whether file was skipped.
        """
        # If files needs to be symlinked, do postprocessing here.
        if self.settings.data.symlink_to_track and not isinstance(media, Video):
            # Determine file extension for symlink
            file_extension = path_media_dst.suffix
            self.media_move_and_symlink(media, path_media_dst, file_extension)

        # Reset quality settings
        if quality_audio_old is not None:
            self.adjust_quality_audio(quality_audio_old)

        if quality_video_old is not None:
            self.adjust_quality_video(quality_video_old)

        # Apply download delay if needed
        if (download_delay and not skip_file) and not self.event_abort.is_set():
            time_sleep: float = round(
                random.SystemRandom().uniform(
                    self.settings.data.download_delay_sec_min, self.settings.data.download_delay_sec_max
                ),
                1,
            )

            self.fn_logger.debug(f"Next download will start in {time_sleep} seconds.")
            time.sleep(time_sleep)

    def media_move_and_symlink(
        self, media: Track | Video, path_media_src: pathlib.Path, file_extension: str
    ) -> pathlib.Path:
        """Move a media file and create a symlink if required.

        Args:
            media (Track | Video): Media item.
            path_media_src (pathlib.Path): Source file path.
            file_extension (str): File extension.

        Returns:
            pathlib.Path: Destination path.
        """
        # Compute tracks path, sanitize and ensure path exists
        file_name_relative: str = format_path_media(
            self.settings.data.format_track,
            media,
            delimiter_artist=self.settings.data.filename_delimiter_artist,
            delimiter_album_artist=self.settings.data.filename_delimiter_album_artist,
            use_primary_album_artist=self.settings.data.use_primary_album_artist,
        )
        path_media_dst: pathlib.Path = (
            pathlib.Path(self.path_base).expanduser() / (file_name_relative + file_extension)
        ).absolute()
        path_media_dst = pathlib.Path(path_file_sanitize(path_media_dst, adapt=True))

        os.makedirs(path_media_dst.parent, exist_ok=True)

        # Move item and symlink it
        if path_media_dst != path_media_src:
            if self.skip_existing:
                skip_file: bool = check_file_exists(path_media_dst, extension_ignore=False)
                skip_symlink: bool = path_media_src.is_symlink()
            else:
                skip_file: bool = False
                skip_symlink: bool = False

            if not skip_file:
                self.fn_logger.debug(f"Move: {path_media_src} -> {path_media_dst}")
                shutil.move(path_media_src, path_media_dst)

            if not skip_symlink:
                self.fn_logger.debug(f"Symlink: {path_media_src} -> {path_media_dst}")
                path_media_dst_relative: pathlib.Path = path_media_dst.relative_to(path_media_src.parent, walk_up=True)

                path_media_src.unlink(missing_ok=True)
                path_media_src.symlink_to(path_media_dst_relative)

        return path_media_dst

    def adjust_quality_audio(self, quality: Quality) -> Quality:
        """Temporarily set audio quality and return the previous value.

        Args:
            quality (Quality): New audio quality.

        Returns:
            Quality: Previous audio quality.
        """
        # Save original quality settings
        quality_old: Quality = self.session.audio_quality
        self.session.audio_quality = quality

        return quality_old

    def adjust_quality_video(self, quality: QualityVideo) -> QualityVideo:
        """Temporarily set video quality and return the previous value.

        Args:
            quality (QualityVideo): New video quality.

        Returns:
            QualityVideo: Previous video quality.
        """
        quality_old: QualityVideo = self.settings.data.quality_video

        self.settings.data.quality_video = quality

        return quality_old

    def _move_file(self, path_file_source: pathlib.Path, path_file_destination: str | pathlib.Path) -> bool:
        """Move a file from source to destination.

        Args:
            path_file_source (pathlib.Path): Source file path.
            path_file_destination (str | pathlib.Path): Destination file path.

        Returns:
            bool: True if moved, False otherwise.
        """
        result: bool

        # Check if the file was downloaded
        if path_file_source and path_file_source.is_file():
            # Move it.
            shutil.move(path_file_source, path_file_destination)

            result = True
        else:
            result = False

        return result

    def _move_lyrics(self, path_lyrics: pathlib.Path, file_media_dst: pathlib.Path) -> bool:
        """Move a lyrics file to the destination.

        Args:
            path_lyrics (pathlib.Path): Source lyrics file.
            file_media_dst (pathlib.Path): Destination media file path.

        Returns:
            bool: True if moved, False otherwise.
        """
        # Build tmp lyrics filename
        path_file_lyrics: pathlib.Path = file_media_dst.with_suffix(EXTENSION_LYRICS)
        result: bool = self._move_file(path_lyrics, path_file_lyrics)

        return result

    def _move_cover(self, path_cover: pathlib.Path, file_media_dst: pathlib.Path) -> bool:
        """Move a cover file to the destination.

        Args:
            path_cover (pathlib.Path): Source cover file.
            file_media_dst (pathlib.Path): Destination media file path.

        Returns:
            bool: True if moved, False otherwise.
        """
        # Build tmp lyrics filename
        path_file_cover: pathlib.Path = file_media_dst.parent / COVER_NAME
        result: bool = self._move_file(path_cover, path_file_cover)

        return result

    def lyrics_to_file(self, dir_destination: pathlib.Path, lyrics: str) -> str:
        """Write lyrics to a temporary file.

        Args:
            dir_destination (pathlib.Path): Directory for the temp file.
            lyrics (str): Lyrics content.

        Returns:
            str: Path to the temp file.
        """
        return self.write_to_tmp_file(dir_destination, mode="x", content=lyrics)

    def cover_to_file(self, dir_destination: pathlib.Path, image: bytes) -> str:
        """Write cover image to a temporary file.

        Args:
            dir_destination (pathlib.Path): Directory for the temp file.
            image (bytes): Image data.

        Returns:
            str: Path to the temp file.
        """
        return self.write_to_tmp_file(dir_destination, mode="xb", content=image)

    def write_to_tmp_file(self, dir_destination: pathlib.Path, mode: str, content: str | bytes) -> str:
        """Write content to a temporary file.

        Args:
            dir_destination (pathlib.Path): Directory for the temp file.
            mode (str): File open mode.
            content (str | bytes): Content to write.

        Returns:
            str: Path to the temp file.
        """
        result: pathlib.Path = dir_destination / str(uuid4())
        encoding: str | None = "utf-8" if isinstance(content, str) else None

        try:
            with open(result, mode=mode, encoding=encoding) as f:
                f.write(content)
        except OSError:
            result = ""

        return result

    @staticmethod
    def cover_data(url: str | None = None, path_file: str | None = None) -> str | bytes:
        """Retrieve cover image data from a URL or file.

        Args:
            url (str | None, optional): URL to download image from. Defaults to None.
            path_file (str | None, optional): Path to image file. Defaults to None.

        Returns:
            str | bytes: Image data or empty string on failure.
        """
        result: str | bytes = ""

        if url:
            response = None
            try:
                response = requests.get(url, timeout=REQUESTS_TIMEOUT_SEC)
                response.raise_for_status()
                result = response.content
            except requests.RequestException:
                # Silently handle download errors (static method has no logger access)
                pass
            finally:
                if response:
                    response.close()
        elif path_file:
            try:
                with open(path_file, "rb") as f:
                    result = f.read()
            except OSError:
                # Silently handle file read errors (static method has no logger access)
                pass

        return result

    def metadata_write(
        self, track: Track, path_media: pathlib.Path, is_parent_album: bool, media_stream: Stream
    ) -> tuple[bool, pathlib.Path | None, pathlib.Path | None]:
        """Write metadata, lyrics, and cover to a media file.

        Args:
            track (Track): Track object.
            path_media (pathlib.Path): Path to media file.
            is_parent_album (bool): Whether this is a parent album.
            media_stream (Stream): Stream object.

        Returns:
            tuple[bool, pathlib.Path | None, pathlib.Path | None]: (Success, path to lyrics, path to cover)
        """
        result: bool = False
        path_lyrics: pathlib.Path | None = None
        path_cover: pathlib.Path | None = None
        release_date: str = (
            track.album.available_release_date.strftime("%Y-%m-%d")
            if track.album.available_release_date
            else track.album.release_date.strftime("%Y-%m-%d") if track.album.release_date else ""
        )
        copy_right: str = track.copyright if hasattr(track, "copyright") and track.copyright else ""
        isrc: str = track.isrc if hasattr(track, "isrc") and track.isrc else ""
        lyrics: str = ""
        lyrics_synced: str = ""
        lyrics_unsynced: str = ""
        cover_data: bytes = None

        if self.settings.data.lyrics_embed or self.settings.data.lyrics_file:
            # Try to retrieve lyrics.
            try:
                lyrics_obj = track.lyrics()

                if lyrics_obj.text:
                    lyrics_unsynced = lyrics_obj.text
                    lyrics = lyrics_unsynced
                if lyrics_obj.subtitles:
                    lyrics_synced = lyrics_obj.subtitles
                    lyrics = lyrics_synced
            except Exception:
                lyrics = ""
                self.fn_logger.debug(f"Could not retrieve lyrics for `{name_builder_item(track)}`.")

        if lyrics and self.settings.data.lyrics_file:
            path_lyrics = self.lyrics_to_file(path_media.parent, lyrics)

        cover_dimension = self.settings.data.metadata_cover_dimension

        if self.settings.data.metadata_cover_embed or (self.settings.data.cover_album_file and is_parent_album):
            # Do not write CoverDimensions.PxORIGIN to metadata, since it can exceed max metadata file size (>16Mb)
            url_cover = track.album.image(
                int(cover_dimension) if cover_dimension != CoverDimensions.PxORIGIN else int(CoverDimensions.Px1280)
            )
            cover_data = self.cover_data(url=url_cover)

        if cover_data and self.settings.data.cover_album_file and is_parent_album:
            if cover_dimension == CoverDimensions.PxORIGIN:
                url_cover_album_file = track.album.image(CoverDimensions.PxORIGIN)
                cover_data_album_file = self.cover_data(url=url_cover_album_file)
            else:
                cover_data_album_file = cover_data

            path_cover = self.cover_to_file(path_media.parent, cover_data_album_file)

        metadata_target_upc = MetadataTargetUPC(self.settings.data.metadata_target_upc)
        target_upc: dict[str, str] = METADATA_LOOKUP_UPC[metadata_target_upc]
        explicit: bool = track.explicit if hasattr(track, "explicit") else False
        title = name_builder_title(track)
        title += METADATA_EXPLICIT if explicit and self.settings.data.mark_explicit else ""

        # `None` values are not allowed.
        m: Metadata = Metadata(
            path_file=path_media,
            target_upc=target_upc,
            lyrics=lyrics_synced,
            lyrics_unsynced=lyrics_unsynced,
            copy_right=copy_right,
            title=title,
            artists=name_builder_artist(track, delimiter=self.settings.data.metadata_delimiter_artist),
            album=track.album.name if track.album else "",
            tracknumber=track.track_num,
            date=release_date,
            isrc=isrc,
            albumartist=name_builder_album_artist(track, delimiter=self.settings.data.metadata_delimiter_album_artist),
            totaltrack=track.album.num_tracks if track.album and track.album.num_tracks else 1,
            totaldisc=track.album.num_volumes if track.album and track.album.num_volumes else 1,
            discnumber=track.volume_num if track.volume_num else 1,
            cover_data=cover_data if self.settings.data.metadata_cover_embed else None,
            album_replay_gain=media_stream.album_replay_gain,
            album_peak_amplitude=media_stream.album_peak_amplitude,
            track_replay_gain=media_stream.track_replay_gain,
            track_peak_amplitude=media_stream.track_peak_amplitude,
            url_share=track.share_url if track.share_url and self.settings.data.metadata_write_url else "",
            replay_gain_write=self.settings.data.metadata_replay_gain,
            upc=track.album.upc if track.album and track.album.upc else "",
            explicit=explicit,
        )

        m.save()

        result = True

        return result, path_lyrics, path_cover

    def items(
        self,
        file_template: str,
        media: Album | Playlist | UserPlaylist | Mix | None = None,
        media_id: str | None = None,
        media_type: MediaType | None = None,
        video_download: bool = False,
        download_delay: bool = True,
        quality_audio: Quality | None = None,
        quality_video: QualityVideo | None = None,
    ) -> None:
        """Download all items in an album, playlist, or mix.

        Args:
            file_template (str): Template for file naming.
            media (Album | Playlist | UserPlaylist | Mix | None, optional): Media item. Defaults to None.
            media_id (str | None, optional): Media ID. Defaults to None.
            media_type (MediaType | None, optional): Media type. Defaults to None.
            video_download (bool, optional): Whether to allow video downloads. Defaults to False.
            download_delay (bool, optional): Whether to delay between downloads. Defaults to True.
            quality_audio (Quality | None, optional): Audio quality. Defaults to None.
            quality_video (QualityVideo | None, optional): Video quality. Defaults to None.
        """
        # Validate and prepare media collection
        validated_media = self._validate_and_prepare_media(media, media_id, media_type, video_download)
        if validated_media is None or not isinstance(validated_media, Album | Playlist | UserPlaylist | Mix):
            return

        media = validated_media

        # Set up download context
        download_context = self._setup_collection_download_context(media, file_template, video_download)
        file_name_relative, list_media_name, list_media_name_short, items, progress_stdout = download_context

        # Set up progress tracking
        progress: Progress = self.progress_overall if self.progress_overall else self.progress
        progress_task: TaskID = progress.add_task(
            f"[green]List '{list_media_name_short}'", total=len(items), visible=progress_stdout
        )

        # Download configuration
        is_album: bool = isinstance(media, Album)
        sort_by_track_num: bool = bool("album_track_num" in file_name_relative or "list_pos" in file_name_relative)
        list_total: int = len(items)

        # Execute downloads
        result_dirs: list[pathlib.Path] = self._execute_collection_downloads(
            items,
            file_name_relative,
            quality_audio,
            quality_video,
            download_delay,
            is_album,
            list_total,
            progress,
            progress_task,
            progress_stdout,
        )

        # Create playlist file if requested
        if self.settings.data.playlist_create:
            self.playlist_populate(set(result_dirs), list_media_name, is_album, sort_by_track_num)

        self.fn_logger.info(f"Finished list '{list_media_name}'.")

    def _setup_collection_download_context(
        self,
        media: Album | Playlist | UserPlaylist | Mix,
        file_template: str,
        video_download: bool,
    ) -> tuple[str, str, str, list, bool]:
        """Set up download context for media collection.

        Args:
            media (Album | Playlist | UserPlaylist | Mix): Media collection.
            file_template (str): Template for file naming.
            video_download (bool): Whether to allow video downloads.

        Returns:
            tuple[str, str, str, list, bool]: (file_name_relative, list_media_name, list_media_name_short, items, progress_stdout)
        """
        # Create file name and path
        file_name_relative: str = format_path_media(
            file_template,
            media,
            delimiter_artist=self.settings.data.filename_delimiter_artist,
            delimiter_album_artist=self.settings.data.filename_delimiter_album_artist,
            use_primary_album_artist=self.settings.data.use_primary_album_artist,
        )

        # Get the name of the list and check, if videos should be included.
        list_media_name: str = name_builder_title(media)
        list_media_name_short: str = list_media_name[:30]

        # Get all items of the list.
        items = items_results_all(media, videos_include=video_download)

        # Determine where to redirect the progress information.
        if self.progress_gui is None:
            progress_stdout: bool = True
        else:
            progress_stdout: bool = False

            self.progress_gui.list_name.emit(list_media_name_short)

        return file_name_relative, list_media_name, list_media_name_short, items, progress_stdout

    def _execute_collection_downloads(
        self,
        items: list,
        file_name_relative: str,
        quality_audio: Quality | None,
        quality_video: QualityVideo | None,
        download_delay: bool,
        is_album: bool,
        list_total: int,
        progress: Progress,
        progress_task: TaskID,
        progress_stdout: bool,
    ) -> list[pathlib.Path]:
        """Execute downloads for all items in the collection.

        Args:
            items (list): List of media items to download.
            file_name_relative (str): Relative file name template.
            quality_audio (Quality | None): Audio quality setting.
            quality_video (QualityVideo | None): Video quality setting.
            download_delay (bool): Whether to apply download delay.
            is_album (bool): Whether this is an album.
            list_total (int): Total number of items.
            progress (Progress): Progress bar instance.
            progress_task (TaskID): Progress task ID.
            progress_stdout (bool): Whether to show progress in stdout.

        Returns:
            list[pathlib.Path]: List of result directories.
        """
        result_dirs: list[pathlib.Path] = []

        # Check if items list is empty
        if not items:
            # Mark progress as complete for empty lists
            progress.update(progress_task, completed=progress.tasks[progress_task].total)

            if not progress_stdout and self.progress_gui:
                self.progress_gui.list_item.emit(100.0)

            return result_dirs

        # Iterate through list items
        while not progress.finished:
            with futures.ThreadPoolExecutor(max_workers=self.settings.data.downloads_concurrent_max) as executor:
                # Dispatch all download tasks to worker threads
                download_futures: list[futures.Future] = [
                    executor.submit(
                        self.item,
                        media=item_media,
                        file_template=file_name_relative,
                        quality_audio=quality_audio,
                        quality_video=quality_video,
                        download_delay=download_delay,
                        is_parent_album=is_album,
                        list_position=count + 1,
                        list_total=list_total,
                    )
                    for count, item_media in enumerate(items)
                ]

                # Process download results
                result_dirs = self._process_download_futures(download_futures, progress, progress_task, progress_stdout)

                # Check for abort signal
                if self.event_abort.is_set():
                    return result_dirs

        return result_dirs

    def _create_download_futures(
        self,
        items: list,
        file_name_relative: str,
        quality_audio: Quality | None,
        quality_video: QualityVideo | None,
        download_delay: bool,
        is_album: bool,
        list_total: int,
    ) -> list[futures.Future]:
        """Create download futures for all items in the collection.

        Args:
            items (list): List of media items to download.
            file_name_relative (str): Relative file name template.
            quality_audio (Quality | None): Audio quality setting.
            quality_video (QualityVideo | None): Video quality setting.
            download_delay (bool): Whether to apply download delay.
            is_album (bool): Whether this is an album.
            list_total (int): Total number of items.

        Returns:
            list[futures.Future]: List of download futures.
        """
        with futures.ThreadPoolExecutor(max_workers=self.settings.data.downloads_concurrent_max) as executor:
            return [
                executor.submit(
                    self.item,
                    media=item_media,
                    file_template=file_name_relative,
                    quality_audio=quality_audio,
                    quality_video=quality_video,
                    download_delay=download_delay,
                    is_parent_album=is_album,
                    list_position=count + 1,
                    list_total=list_total,
                )
                for count, item_media in enumerate(items)
            ]

    def _process_download_futures(
        self,
        futures_list: list[futures.Future],
        progress: Progress,
        progress_task: TaskID,
        progress_stdout: bool,
    ) -> list[pathlib.Path]:
        """Process download futures and collect results.

        Args:
            futures_list (list[futures.Future]): List of download futures.
            progress (Progress): Progress bar instance.
            progress_task (TaskID): Progress task ID.
            progress_stdout (bool): Whether to show progress in stdout.

        Returns:
            list[pathlib.Path]: List of result directories.
        """
        result_dirs: list[pathlib.Path] = []

        # Report results as they become available
        for future in futures.as_completed(futures_list):
            # Retrieve result
            status, result_path_file = future.result()

            if result_path_file:
                result_dirs.append(result_path_file.parent)

            # Advance progress bar.
            progress.advance(progress_task)

            if not progress_stdout:
                self.progress_gui.list_item.emit(progress.tasks[progress_task].percentage)

            # If app is terminated (CTRL+C)
            if self.event_abort.is_set():
                # Cancel all not yet started tasks
                for f in futures_list:
                    f.cancel()

                break

        return result_dirs

    def playlist_populate(
        self, dirs_scoped: set[pathlib.Path], name_list: str, is_album: bool, sort_alphabetically: bool
    ) -> list[pathlib.Path]:
        """Create playlist files (m3u) for downloaded tracks in each directory.

        Args:
            dirs_scoped (set[pathlib.Path]): Set of directories containing tracks.
            name_list (str): Name of the playlist.
            is_album (bool): Whether this is an album.
            sort_alphabetically (bool): Whether to sort tracks alphabetically.

        Returns:
            list[pathlib.Path]: List of created playlist file paths.
        """
        result: list[pathlib.Path] = []

        # For each dir, which contains tracks
        for dir_scoped in dirs_scoped:
            # Sanitize final playlist name to fit into OS boundaries.
            path_playlist = dir_scoped / sanitize_filename(PLAYLIST_PREFIX + name_list + PLAYLIST_EXTENSION)
            path_playlist = pathlib.Path(path_file_sanitize(path_playlist, adapt=True))

            self.fn_logger.debug(f"Playlist: Creating {path_playlist}")

            # Get all tracks in the directory
            path_tracks: list[pathlib.Path] = []

            for extension_audio in AudioExtensionsValid:
                path_tracks = path_tracks + list(dir_scoped.glob(f"*{extension_audio!s}"))

            # Sort alphabetically, e.g. if items are prefixed with numbers
            if sort_alphabetically:
                path_tracks.sort()
            elif not is_album:
                # If it is not an album sort by creation time
                path_tracks.sort(
                    key=lambda x: x.stat().st_birthtime if hasattr(x.stat(), "st_birthtime") else x.stat().st_ctime
                )

            # Write data to m3u file
            with path_playlist.open(mode="w", encoding="utf-8") as f:
                for path_track in path_tracks:
                    # If it's a symlink write the relative file path to the actual track into the playlist file
                    if path_track.is_symlink():
                        media_file_target = path_track.resolve().relative_to(path_track.parent, walk_up=True)
                    else:
                        media_file_target = path_track.name

                    f.write(str(media_file_target) + os.linesep)

            result.append(path_playlist)

        return result

    def _video_convert(self, path_file: pathlib.Path) -> pathlib.Path:
        """Convert a TS video file to MP4 using ffmpeg.

        Args:
            path_file (pathlib.Path): Path to the TS file.

        Returns:
            pathlib.Path: Path to the converted MP4 file.
        """
        path_file_out: pathlib.Path = path_file.with_suffix(AudioExtensions.MP4)

        self.fn_logger.debug(f"Converting video: {path_file.name} -> {path_file_out.name}")

        ffmpeg = (
            FFmpeg(executable=self.settings.data.path_binary_ffmpeg)
            .option("y")
            .option("hide_banner")
            .option("nostdin")
            .input(url=path_file)
            .output(url=path_file_out, codec="copy", map=0, loglevel="quiet")
        )

        ffmpeg.execute()

        self.fn_logger.debug(f"Video conversion complete: {path_file_out.name}")

        return path_file_out

    def _extract_flac(self, path_media_src: pathlib.Path) -> pathlib.Path:
        """Extract FLAC audio from a media file using ffmpeg.

        Args:
            path_media_src (pathlib.Path): Path to the source media file.

        Returns:
            pathlib.Path: Path to the extracted FLAC file.
        """
        path_media_out = path_media_src.with_suffix(AudioExtensions.FLAC)

        self.fn_logger.debug(f"Extracting FLAC: {path_media_src.name} -> {path_media_out.name}")

        ffmpeg = (
            FFmpeg(executable=self.settings.data.path_binary_ffmpeg)
            .option("hide_banner")
            .option("nostdin")
            .input(url=path_media_src)
            .output(
                url=path_media_out,
                map=0,
                movflags="use_metadata_tags",
                acodec="copy",
                map_metadata="0:g",
                loglevel="quiet",
            )
        )

        ffmpeg.execute()

        self.fn_logger.debug(f"FLAC extraction complete: {path_media_out.name}")

        return path_media_out

    def _extract_video_stream(self, m3u8_variant: m3u8.M3U8, quality: int) -> tuple[m3u8.M3U8 | bool, str]:
        """Extract the best matching video stream from an m3u8 variant playlist.

        Args:
            m3u8_variant (m3u8.M3U8): The m3u8 variant playlist.
            quality (int): Desired video quality (vertical resolution).

        Returns:
            tuple[m3u8.M3U8 | bool, str]: (Selected m3u8 playlist or False, codecs string)
        """
        m3u8_playlist: m3u8.M3U8 | bool = False
        resolution_best: int = 0
        mime_type: str = ""

        if m3u8_variant.is_variant:
            for playlist in m3u8_variant.playlists:
                if resolution_best < playlist.stream_info.resolution[1]:
                    resolution_best = playlist.stream_info.resolution[1]
                    m3u8_playlist = m3u8.load(playlist.uri)
                    mime_type = playlist.stream_info.codecs

                    if quality == playlist.stream_info.resolution[1]:
                        break

        return m3u8_playlist, mime_type
