import 'dart:core';

import 'package:webfeed/domain/dublin_core/dublin_core.dart';
import 'package:webfeed/domain/rss_category.dart';
import 'package:webfeed/domain/rss_cloud.dart';
import 'package:webfeed/domain/rss_image.dart';
import 'package:webfeed/domain/rss_item.dart';
import 'package:webfeed/util/xml.dart';
import 'package:xml/xml.dart';

import 'rss_itunes.dart';

class RssFeed {
  final String title;
  final String author;
  final String description;
  final String link;
  final List<RssItem> items;

  final RssImage image;
  final RssCloud cloud;
  final List<RssCategory> categories;
  final List<String> skipDays;
  final List<int> skipHours;
  final String lastBuildDate;
  final String language;
  final String generator;
  final String copyright;
  final String docs;
  final String managingEditor;
  final String rating;
  final String webMaster;
  final int ttl;
  final DublinCore dc;
  final RssItunes itunes;

  RssFeed({
    this.title,
    this.author,
    this.description,
    this.link,
    this.items,
    this.image,
    this.cloud,
    this.categories,
    this.skipDays,
    this.skipHours,
    this.lastBuildDate,
    this.language,
    this.generator,
    this.copyright,
    this.docs,
    this.managingEditor,
    this.rating,
    this.webMaster,
    this.ttl,
    this.dc,
    this.itunes,
  });

  factory RssFeed.parse(String xmlString) {
    var document = XmlDocument.parse(xmlString);
    XmlElement channelElement;
    try {
      channelElement = document.findAllElements('channel').first;
    } on StateError {
      throw ArgumentError('channel not found');
    }

    return RssFeed(
      title: findElementOrNull(channelElement, 'title')?.text,
      author: findElementOrNull(channelElement, 'author')?.text,
      description: findElementOrNull(channelElement, 'description')?.text,
      link: findElementOrNull(channelElement, 'link')?.text,
      items: channelElement.findElements('item').map((element) {
        return RssItem.parse(element);
      }).toList(),
      image: RssImage.parse(findElementOrNull(channelElement, 'image')),
      cloud: RssCloud.parse(findElementOrNull(channelElement, 'cloud')),
      categories: channelElement.findElements('category').map((element) {
        return RssCategory.parse(element);
      }).toList(),
      skipDays: findElementOrNull(channelElement, 'skipDays')
              ?.findAllElements('day')
              ?.map((element) {
            return element.text;
          })?.toList() ??
          [],
      skipHours: findElementOrNull(channelElement, 'skipHours')
              ?.findAllElements('hour')
              ?.map((element) {
            return int.tryParse(element.text ?? '0');
          })?.toList() ??
          [],
      lastBuildDate: findElementOrNull(channelElement, 'lastBuildDate')?.text,
      language: findElementOrNull(channelElement, 'language')?.text,
      generator: findElementOrNull(channelElement, 'generator')?.text,
      copyright: findElementOrNull(channelElement, 'copyright')?.text,
      docs: findElementOrNull(channelElement, 'docs')?.text,
      managingEditor: findElementOrNull(channelElement, 'managingEditor')?.text,
      rating: findElementOrNull(channelElement, 'rating')?.text,
      webMaster: findElementOrNull(channelElement, 'webMaster')?.text,
      ttl: int.tryParse(findElementOrNull(channelElement, 'ttl')?.text ?? '0'),
      dc: DublinCore.parse(channelElement),
      itunes: RssItunes.parse(channelElement),
    );
  }
}