// Copyright (C) 2022 WYATT GROUP
// Please see the AUTHORS file for details.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

import 'package:http/http.dart';
import 'package:webfeed/webfeed.dart';
import 'package:wyatt_medium_feeds/src/medium_article.dart';

class MediumFeed {
  final String? username;
  final bool mediumSubdomain;
  final String? publicationName;
  final String? customDomain;
  final String? tagName;
  final String? topicName;

  final String url;

  RssFeed? _feed;

  RssFeed get feed {
    if (_feed == null) {
      throw StateError('Feed has not been parsed yet.');
    }
    return _feed!;
  }

  String get title => feed.title ?? '';

  String get description => feed.description ?? '';

  String get image => feed.image?.url ?? '';

  List<MediumArticle> get articles {
    final articles = <MediumArticle>[];
    for (final i in feed.items ?? <RssItem>[]) {
      articles.add(MediumArticle(i));
    }
    return articles;
  }

  MediumFeed.fromUsername(
    this.username, {
    bool subdomain = false,
    String proxy = 'https://cros-anywhere.herokuapp.com/',
  })  : mediumSubdomain = subdomain,
        publicationName = null,
        customDomain = null,
        tagName = null,
        topicName = null,
        url = subdomain
            ? '${proxy}https://$username.medium.com/feed'
            : '${proxy}https://medium.com/feed/@$username';

  MediumFeed.fromPublicationName(
    this.publicationName, {
    String proxy = 'https://cros-anywhere.herokuapp.com/',
  })  : username = null,
        mediumSubdomain = false,
        customDomain = null,
        tagName = null,
        topicName = null,
        url = '${proxy}https://medium.com/feed/$publicationName';

  MediumFeed.fromCustomDomain(
    this.customDomain, {
    String proxy = 'https://cros-anywhere.herokuapp.com/',
  })  : username = null,
        mediumSubdomain = false,
        publicationName = null,
        tagName = null,
        topicName = null,
        url = '${proxy}https://$customDomain/feed';

  MediumFeed.fromTagName({
    this.publicationName,
    this.tagName,
    String proxy = 'https://cros-anywhere.herokuapp.com/',
  })  : username = null,
        mediumSubdomain = false,
        customDomain = null,
        topicName = null,
        url =
            '${proxy}https://medium.com/feed/$publicationName/tagged/$tagName';

  MediumFeed.fromTopicName(
    this.topicName, {
    String proxy = 'https://cros-anywhere.herokuapp.com/',
  })  : username = null,
        mediumSubdomain = false,
        customDomain = null,
        publicationName = null,
        tagName = null,
        url = '${proxy}https://medium.com/feed/tag/$topicName';

  Future<RssFeed> parse() async {
    final xmlString = await read(Uri.parse(url));
    _feed = RssFeed.parse(xmlString);
    return _feed!;
  }
}