import 'dart:convert';
import 'package:html/dom.dart';
import 'package:html/parser.dart' as parser;
import '../../../youtube_explode_dart.dart';
import '../../extensions/helpers_extension.dart';
import '../../playlists/playlist_id.dart';
import '../../retry.dart';
import '../../search/related_query.dart';
import '../../search/search_playlist.dart';
import '../../search/search_video.dart';
import '../../videos/videos.dart';
import '../youtube_http_client.dart';
///
class SearchPage {
static final _xsfrTokenExp = RegExp('"XSRF_TOKEN":"(.+?)"');
///
final String queryString;
final Document _root;
_InitialData _initialData;
String _xsrfToken;
///
_InitialData get initialData =>
_initialData ??= _InitialData(json.decode(_matchJson(_extractJson(
_root
.querySelectorAll('script')
.map((e) => e.text)
.toList()
.firstWhere((e) => e.contains('window["ytInitialData"] =')),
'window["ytInitialData"] ='))));
///
String get xsfrToken => _xsrfToken ??= _xsfrTokenExp
.firstMatch(_root
.querySelectorAll('script')
.firstWhere((e) => _xsfrTokenExp.hasMatch(e.text))
.text)
.group(1);
String _extractJson(String html, String separator) {
return _matchJson(
html.substring(html.indexOf(separator) + separator.length));
}
String _matchJson(String str) {
var bracketCount = 0;
int lastI;
for (var i = 0; i < str.length; i++) {
lastI = i;
if (str[i] == '{') {
bracketCount++;
} else if (str[i] == '}') {
bracketCount--;
} else if (str[i] == ';') {
if (bracketCount == 0) {
return str.substring(0, i);
}
}
}
return str.substring(0, lastI + 1);
}
///
SearchPage(this._root, this.queryString,
[_InitialData initalData, String xsfrToken])
: _initialData = initalData,
_xsrfToken = xsfrToken;
///
// TODO: Replace this in favour of async* when quering;
Future nextPage(YoutubeHttpClient httpClient) async {
if (initialData.continuation == '') {
return null;
}
return get(httpClient, queryString,
ctoken: initialData.continuation,
itct: initialData.clickTrackingParams,
xsrfToken: xsfrToken);
}
///
static Future get(
YoutubeHttpClient httpClient, String queryString,
{String ctoken, String itct, String xsrfToken}) {
var url =
'https://www.youtube.com/results?search_query=${Uri.encodeQueryComponent(queryString)}';
if (ctoken != null) {
assert(itct != null, 'If ctoken is not null itct cannot be null');
url += '&pbj=1';
url += '&ctoken=${Uri.encodeQueryComponent(ctoken)}';
url += '&continuation=${Uri.encodeQueryComponent(ctoken)}';
url += '&itct=${Uri.encodeQueryComponent(itct)}';
}
return retry(() async {
Map body;
if (xsrfToken != null) {
body = {'session_token': xsrfToken};
}
var raw = await httpClient.postString(url, body: body);
if (ctoken != null) {
return SearchPage(
null, queryString, _InitialData(json.decode(raw)[1]), xsrfToken);
}
return SearchPage.parse(raw, queryString);
});
}
///
SearchPage.parse(String raw, this.queryString) : _root = parser.parse(raw);
}
class _InitialData {
// Json parsed map
final Map _root;
_InitialData(this._root);
/* Cache results */
List _searchContent;
List _relatedVideos;
List _relatedQueries;
String _continuation;
String _clickTrackingParams;
List