import RSSParser from 'rss-parser';

export type PodcastFeed = {
  image: {
    url: string,
    title: string;
  },
  paginationLinks:
  {
    self: string;
  },
  title: string;
  description: string;
  pubDate: string;
  generator: string;
  language: string;
  copyright: string;
  lastBuildDate: string;
  itunes: {
    owner: {
      name: string;
    },
    image: string;
    categories: string[]
    categoriesWithSubs: {
      name: string;
      subs: [{name: string}],
    }[]
    keywords:string[]
    author: string;
    subtitle: string;
    summary: string;
    explicit: string;
  },
  siteUrl: string;
 };

export type PodcastItem = {
  creator: string;
  title: string;
  link: string;
  pubDate: string;
  author: string;
  'document:encoded': string;
  'document:encodedSnippet': string;
  enclosure: {
    url: string;
    length: string;
    type: string;
  };
  document: string;
  documentSnippet: string;
  guid: string;
  isoDate: string;
  itunes: {
    author: string;
    subtitle: string;
    summary: string;
    explicit: string;
    duration: string;
    image: string;
    episode: string;
    keywords: string;
  },
};

export type Podcast = PodcastFeed & RSSParser.Output<PodcastItem>;

const rss = new RSSParser<PodcastFeed, PodcastItem>();

const parse = async (url: string): Promise<Podcast> => {
  return await rss.parseURL(url);
};

function getPosition(value: string, sub: string, index: number): number {
  const result = value.split(sub, index).join(sub).length;
  return result < value.length ? result : -1;
}

/**
 * Can handle hh:mm:ss, or mm:ss, or ss
 */
const convertDurationToSeconds = (duration: string): number => {
  const firstColon = getPosition(duration, ':', 1);
  const secondColon = getPosition(duration, ':', 2);

  if (firstColon === -1) return Number(duration);

  if (secondColon === -1) {
    const minutes = Number(duration.substring(0, firstColon));
    const seconds = Number(duration.substring(firstColon + 1));
    return (minutes * 60) + seconds;
  }

  const hours = Number(duration.substring(0, firstColon));
  const minutes = Number(duration.substring(firstColon + 1, secondColon));
  const seconds = Number(duration.substring(secondColon + 1));
  return (hours * 60 * 60) + (minutes * 60) + seconds;
};

const durationSeconds = (items: PodcastItem[]): number => {
  return items
    .map((item: PodcastItem) => {
      const seconds = convertDurationToSeconds(item?.itunes?.duration ?? '0');
      return seconds;
    })
    .reduce((c, n) => c + n, 0);
};

const durationHours = (items: PodcastItem[]): number => {
  const seconds = durationSeconds(items);
  return seconds > 0 ? Math.ceil(seconds / 3600) : 0;
};

const transcriptionCost = (items: PodcastItem[]): number => {
  const hours = durationHours(items);
  return hours * 0.5 * 100;
};

const RSSUtil = {
  parse,
  durationSeconds,
  durationHours,
  transcriptionCost,
};

export default RSSUtil;