const { refreshApiSource, refreshRssFeed } = require('../../data-source-refresh');

const TASK = {
  key: 'startup-data-source-refresh',
  category: 'data-source',
};

function scheduleStartupDataSourceRefreshes(options) {
  const backgroundTaskQueue = options && options.backgroundTaskQueue;
  const pool = options && options.pool;
  const common = options && options.common;
  const dataSourceStartupRefreshStaggerMs = Math.max(100, Number(options && options.dataSourceStartupRefreshStaggerMs || 250));

  if (!backgroundTaskQueue || !pool || !common) {
    throw new Error('scheduleStartupDataSourceRefreshes requires the startup refresh dependencies.');
  }

  const staggerMs = Math.max(100, Number(dataSourceStartupRefreshStaggerMs || 250));

  function buildStartupSource(type, id, name, run) {
    return {
      type: type,
      id: Number(id),
      name: name,
      run: run
    };
  }

  return (async function () {
    const apiSourcesData = await common.fetchApiSourcesData(pool);
    const rssFeedsData = await common.fetchRssFeedsData(pool);
    const startupSources = [];

    (apiSourcesData.apiSources || []).forEach(function (apiSource) {
      startupSources.push(buildStartupSource('api-source', apiSource.id, apiSource.name, function () {
        return refreshApiSource(pool, common, apiSource, null);
      }));
    });

    (rssFeedsData.rssFeeds || []).forEach(function (rssFeed) {
      startupSources.push(buildStartupSource('rss-feed', rssFeed.id, rssFeed.name, function () {
        return refreshRssFeed(pool, common, rssFeed.id, rssFeed.feed_url, rssFeed.item_limit, null);
      }));
    });

    // Stagger startup refreshes to avoid a burst against the DB/player.
    startupSources.forEach(function (source, index) {
      const startupDelayMs = index * staggerMs;

      setTimeout(function () {
        backgroundTaskQueue.enqueueTask({
          key: TASK.key + ':' + source.type + ':' + source.id + ':' + Date.now(),
          title: source.type === 'rss-feed' ? 'RSS feed refresh' : 'API source refresh',
          category: TASK.category,
          taskType: 'data-source-refresh',
          metadata: {
            sourceType: source.type,
            sourceId: source.id,
            sourceName: source.name,
            startupRefresh: true
          },
          payload: {
            sourceType: source.type,
            sourceId: source.id,
            sourceName: source.name,
            startupRefresh: true
          }
        }).catch(function (error) {
          console.warn('Unable to queue startup refresh for ' + source.type + ' ' + source.id + ':', error);
        });
      }, startupDelayMs);
    });
  })();
}

module.exports = { scheduleStartupDataSourceRefreshes };