youtube_data_parser.dart

import 'dart:async';
import 'dart:convert';

import 'package:html/parser.dart';
import 'package:http/http.dart' as http;

class VideoService extends BaseService {
  final KeyStorageService _keyStorageService = locator<KeyStorageService>();

  Future<List<Channel>> getChannels(String searchQuery) async {
    final List<Channel> result = [];
    try {
      final Map<String, dynamic> data =
          await getYoutubeContents("/results?sp=EgIQAg%253D%253D&search_query=${Uri.encodeComponent(searchQuery)}");

      if (data != null) {
        List<dynamic> channelDataList =
            data["contents"]["sectionListRenderer"]["contents"][0]["itemSectionRenderer"]["contents"];

        channelDataList.forEach((channelData) {
          var channelRenderer = channelData["compactChannelRenderer"];
          String channelId = channelRenderer["channelId"];
          String thumbnail = channelRenderer["thumbnail"]["thumbnails"][0]["url"];
          if (thumbnail.startsWith("//")) {
            thumbnail = "https:${thumbnail}";
          }
          String displayName = channelRenderer["displayName"]["runs"][0]["text"];
          var videoCountTextData = channelRenderer["videoCountText"]["runs"];
          String videoCountText =
              "${videoCountTextData[0]["text"]} ${videoCountTextData[1]["text"]} ${videoCountTextData[2]["text"]}";
          String subscriberCountText = channelRenderer["subscriberCountText"]["runs"][0]["text"];

          result.add(Channel(
            channelId: channelId,
            thumbnail: thumbnail,
            displayName: displayName,
            videoCountText: videoCountText,
            subscriberCountText: subscriberCountText,
          ));
        });
      }
    } catch (e) {
      print("get videos error : $e");
    }
    return result;
  }

  Future<List<Video>> getChannelVideos() async {
    final List<Channel> channels = _keyStorageService.subscriptionChannels ?? MemoryStorageService().defaultChannels;
    final List<Video> result = [];
    var futures = <Future>[];
    try {
      channels.forEach((channel) {
        futures.add(getYoutubeContents("/channel/${channel.channelId}/videos").then((data) {
          if (data != null) {
            List<dynamic> videoDataList = data["contents"]["singleColumnBrowseResultsRenderer"]["tabs"][1]
                ["tabRenderer"]["content"]["sectionListRenderer"]["contents"][0]["itemSectionRenderer"]["contents"];

            Future.forEach(videoDataList, (videoData) async {
              try {
                final Video video = _parseVideoData(videoData);
                result.add(video);
              } catch (e) {
                print("$videoData : extract url error : $e");
              }
            });
          }
        }));
      });
    } catch (e) {
      print("get videos error : $e");
    }

    await Future.wait(futures);

    return result;
  }

  Future<List<Video>> searchVideos(String searchQuery) async {
    final List<Video> result = [];
    try {
      Map<String, dynamic> data = await getYoutubeContents("/results?search_query=${Uri.encodeComponent(searchQuery)}");
      if (data != null) {
        List<dynamic> videoDataList =
            data["contents"]["sectionListRenderer"]["contents"][0]["itemSectionRenderer"]["contents"];

        Future.forEach(videoDataList, (videoData) async {
          try {
            final Video video = _parseVideoData(videoData);
            result.add(video);
          } catch (e) {
            print("$videoData : extract url error : $e");
          }
        });
      }
    } catch (e) {
      print("get videos error : $e");
    }
    return result;
  }

  static final String youtubeUrl = "https://m.youtube.com";
  Future<Map<String, dynamic>> getYoutubeContents(String uri) async {
    final String url = "${youtubeUrl}${uri}";
    Map<String, dynamic> result;
    try {
      var response = await http.get(
        url,
        headers: {
          "user-agent":
              "Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.130 Mobile Safari/537.36",
        },
      );

      if (response.statusCode == 200) {
        final String htmlString = response.body;

        var document = parse(htmlString);

        String initData = document.querySelector("#initial-data").nodes[0].text;
        initData = initData.replaceAll("<!--", "").replaceAll("-->", "").trim();

        result = jsonDecode(initData);
      }
    } catch (e) {
      print("$url => get html error : $e");
    }
    return result;
  }

  Video _parseVideoData(Map<String, dynamic> videoData) {
    Map<String, dynamic> data = videoData["compactVideoRenderer"];
    String videoId = data["videoId"];
    String title = data["title"]["runs"][0]["text"];
    String thumbnail = "https://i.ytimg.com/vi_webp/${videoId}/sddefault.webp";
    String viewCountText = data["viewCountText"]["runs"][0]["text"];
    String lengthText = data["lengthText"]["runs"][0]["text"];
    String publishedTimeText = "";
    try {
      publishedTimeText = data["publishedTimeText"]["runs"][0]["text"];
    } catch (e) {
      print("parse publishedTimeText error: $e");
    }

//    String videoPlayUrl = await CommonUtils.extractYoutubeUrl(videoId);

    return Video(
      videoId: videoId,
      title: title,
      thumbnail: thumbnail,
      publishedTimeText: publishedTimeText,
      viewCountText: viewCountText,
      lengthText: lengthText,
//      videoPlayUrl: videoPlayUrl,
    );
  }

  Future<List<Video>> getNextVideos(String videoId) async {
    final List<Video> result = [];
    try {
      Map<String, dynamic> data = await getYoutubeContents("/watch?v=${videoId}");
      if (data != null) {
        List<dynamic> contents = data["contents"]["singleColumnWatchNextResults"]["results"]["results"]["contents"];

        for (Map<String, dynamic> content in contents) {
          bool hasKey = content.containsKey("itemSectionRenderer");
          if (hasKey) {
            List<dynamic> videoDataList = content["itemSectionRenderer"]["contents"];

            videoDataList = videoDataList.sublist(1, videoDataList.length);
            videoDataList.forEach((videoData) {
              try {
                final Video video = _parseVideoData(videoData);
                result.add(video);
              } catch (e) {
                print("$videoData : extract url error : $e");
              }
            });
          }
        }
      }
    } catch (e) {
      print("get videos error : $e");
    }
    return result;
  }
}