from __future__ import unicode_literals

import os

import googleapiclient.discovery
import googleapiclient.errors
import youtube_dl


class MyLogger(object):
    def debug(self, msg):
        pass

    def warning(self, msg):
        pass

    def error(self, msg):
        print(msg)


def my_hook(d):
    if d['status'] == 'finished':
        print('Download finished!')


class SaveMyPlaylist:
    SCOPES = ['https://www.googleapis.com/auth/youtube.readonly']
    API_NAME = 'youtube'
    API_VERSION = 'v3'

    CHANNEL = 0
    TITLE = 1
    VIDEO_ID = 2


    ILLEGAL_CHARS = ['NUL', '\',''//', ':', '*', '"', '<', '>', '|']

    def __init__(self, apiKey, playlistId):
        self.__apiKey = apiKey
        self.__playlistId = playlistId
        self.__items = self.__fetch_playlist_items()

    def __fetch_playlist_items(self):
        youtube = googleapiclient.discovery.build(self.API_NAME, self.API_VERSION, developerKey=self.__apiKey)
        request = youtube.playlistItems().list(
            part='snippet',
            playlistId=self.__playlistId,
            maxResults=50,
        )

        response = request.execute()

        items = []

        for item in response['items']:
            snippet = item['snippet']
            title = snippet['title']
            channel = snippet['channelTitle']
            videoId = snippet['resourceId']['videoId']
            items.append((channel, title, videoId))
            print('{} - {} ({})'.format(channel, title, videoId))

        print('\n>>> Found {} items\n'.format(len(items)))
        return items

    def download_items(self, destinationFolder, debug=False):
        print('>>> Scanning destination folder...')
        downloadedVideos = [f for f in os.listdir(destinationFolder) if
                            os.path.isfile(os.path.join(destinationFolder, f))]

        print('>>> Found {} already downloaded videos'.format(len(downloadedVideos)))

        print('\n>>> Started Downloading...')
        newVideos = []
        for idx, item in enumerate(self.__items):
            fileName = '{} - {}.mp4'.format(item[self.TITLE], item[self.CHANNEL])
            fileName = self.__escape_file_name(fileName)
            if fileName in downloadedVideos:
                print('Skipping {}/{}: "{}" as it already exists'.format(idx + 1, len(self.__items), fileName))
                continue

            print('Downloading {}/{}: "{}"'.format(idx + 1, len(self.__items), fileName))
            newVideos.append(item)

            ydl_opts = {
                'format': 'bestaudio/best',
                'merge_output_format': 'mp4',
                'outtmpl': os.path.join(destinationFolder, fileName),
                'logger': MyLogger(),
                'progress_hooks': [my_hook],
            }

            if debug:
                continue

            with youtube_dl.YoutubeDL(ydl_opts) as ydl:
                ydl.download(['https://www.youtube.com/watch?v={}'.format(item[self.VIDEO_ID])])

        print('\n>>> Finished Downloading')
        print('Downloaded {} new videos'.format(len(newVideos)))

    def __escape_file_name(self, fileName):
        for char in self.ILLEGAL_CHARS:
            fileName = fileName.replace(char, '')

        return fileName


if __name__ == '__main__':
    API_KEY = 'AIzaSyD1cQOPzYDRe5pylXEFsQw6u-MaBSOX09Y'
    PLAYLIST_ID = 'PL7F-5FkCMt0F86pdKUaiTStIloZYDVfzl'
    DESTINATION_FOLDER = 'C:/Users/ROGO2/Desktop/123'

    saveMyPlaylist = SaveMyPlaylist(API_KEY, PLAYLIST_ID)
    saveMyPlaylist.download_items(DESTINATION_FOLDER, True)