from pytube import Playlist
import ffmpeg
import os

def make_alpha_numeric(string: str) -> str:
    return "".join(char for char in string if char.isalnum())

class YouLoadPlayList:
    """A class for download and handling youtube playlists"""

    DOWNLOAD_TYPES = ["default", "highest", "lowest", "mp3", "720p", "480p", "360p", "240p", "144p"]
    DEFAULT_DOWNLOAD_TYPE = "default"

    def __init__(self, link: str):
        self.yt_playlist = Playlist(link)
        self.video_count = len(self.yt_playlist.videos)
        self.folder_name = make_alpha_numeric(self.yt_playlist.title)
        self.download_type = self.DEFAULT_DOWNLOAD_TYPE

    def generate_video_info(self, video_num: int) -> str:
        """Returns information on video in playlist at 'video_num'"""

        video = self.yt_playlist.videos[video_num]
        video_size = video.streams.get_highest_resolution().filesize // 1048576
        return f"Title: {video.title}, Size: {video_size} MB"

    def set_download_directory(self, directory: str) -> None:
        """Sets where the playlist folder will be downloaded"""
        self.folder_name = os.path.join(directory, make_alpha_numeric(self.yt_playlist.title))

    def prepare_for_download(self) -> None:
        """Gets the playlist ready for download. Creates the output folder and that stuff."""
        os.mkdir(self.folder_name)

    def download_video(self, video_num: int, use_prefix: bool) -> str:
        """Download video at 'video_num'"""
        video = self.yt_playlist.videos[video_num]

        # Create prefix.
        filename_prefix = ""

        if use_prefix:
            filename_prefix = str(video_num + 1) + " "

        # Download this fucker.
        if self.download_type == "default":
            # video.streams.first().download(output_path=self.folder_name, filename_prefix=filename_prefix)
        elif self.download_type == "highest":
            video.streams.get_highest_resolution().download(output_path=self.folder_name, filename_prefix=filename_prefix)
        elif self.download_type == "lowest":
            video.streams.get_lowest_resolution().download(output_path=self.folder_name, filename_prefix=filename_prefix)
        elif self.download_type == "mp3":
            file_path = video.streams.first().download(output_path=self.folder_name, filename_prefix=filename_prefix)

            # To mp3.
            file_path_mp3 = file_path[:-4] + ".mp3"
            ffmpeg.input(file_path).output(file_path_mp3).run()

            # Remove mp4 file.
            os.remove(file_path)

        else:
            video.streams.get_by_resolution(self.download_type).download(output_path=self.folder_name, filename_prefix=filename_prefix)

        return f"Title: {video.title}"