const axios = require('axios');
const cache = require('./cache');
const { getTorrents } = require('./qbittorrent');
const {
  getSABnzbdInstances,
  getSonarrInstances,
  getRadarrInstances
} = require('./config');

const rawPollInterval = (process.env.POLL_INTERVAL || '').toLowerCase();
const POLL_INTERVAL = (rawPollInterval === 'off' || rawPollInterval === 'false' || rawPollInterval === 'disabled')
  ? 0
  : (parseInt(process.env.POLL_INTERVAL, 10) || 5000);
const POLLING_ENABLED = POLL_INTERVAL > 0;

let polling = false;

async function pollAllServices() {
  if (polling) {
    console.log('[Poller] Previous poll still running, skipping');
    return;
  }
  polling = true;
  const start = Date.now();

  try {
    const sabInstances = getSABnzbdInstances();
    const sonarrInstances = getSonarrInstances();
    const radarrInstances = getRadarrInstances();

    // All fetches in parallel
    const [
      sabQueues, sabHistories,
      sonarrTagsResults, sonarrQueues, sonarrHistories, sonarrSeriesResults,
      radarrQueues, radarrHistories, radarrMoviesResults, radarrTagsResults,
      qbittorrentTorrents
    ] = await Promise.all([
      // SABnzbd
      Promise.all(sabInstances.map(inst =>
        axios.get(`${inst.url}/api`, {
          params: { mode: 'queue', apikey: inst.apiKey, output: 'json' }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] SABnzbd ${inst.id} queue error:`, err.message);
          return { instance: inst.id, data: { queue: { slots: [] } } };
        })
      )),
      Promise.all(sabInstances.map(inst =>
        axios.get(`${inst.url}/api`, {
          params: { mode: 'history', apikey: inst.apiKey, output: 'json', limit: 20 }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] SABnzbd ${inst.id} history error:`, err.message);
          return { instance: inst.id, data: { history: { slots: [] } } };
        })
      )),
      // Sonarr
      Promise.all(sonarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/tag`, {
          headers: { 'X-Api-Key': inst.apiKey }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Sonarr ${inst.id} tags error:`, err.message);
          return { instance: inst.id, data: [] };
        })
      )),
      Promise.all(sonarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/queue`, {
          headers: { 'X-Api-Key': inst.apiKey },
          params: { includeSeries: true, includeEpisode: true }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Sonarr ${inst.id} queue error:`, err.message);
          return { instance: inst.id, data: { records: [] } };
        })
      )),
      Promise.all(sonarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/history`, {
          headers: { 'X-Api-Key': inst.apiKey },
          params: { pageSize: 20, includeSeries: true, includeEpisode: true }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Sonarr ${inst.id} history error:`, err.message);
          return { instance: inst.id, data: { records: [] } };
        })
      )),
      Promise.all(sonarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/series`, {
          headers: { 'X-Api-Key': inst.apiKey }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Sonarr ${inst.id} series error:`, err.message);
          return { instance: inst.id, data: [] };
        })
      )),
      // Radarr
      Promise.all(radarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/queue`, {
          headers: { 'X-Api-Key': inst.apiKey },
          params: { includeMovie: true }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Radarr ${inst.id} queue error:`, err.message);
          return { instance: inst.id, data: { records: [] } };
        })
      )),
      Promise.all(radarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/history`, {
          headers: { 'X-Api-Key': inst.apiKey },
          params: { pageSize: 20, includeMovie: true }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Radarr ${inst.id} history error:`, err.message);
          return { instance: inst.id, data: { records: [] } };
        })
      )),
      Promise.all(radarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/movie`, {
          headers: { 'X-Api-Key': inst.apiKey }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Radarr ${inst.id} movies error:`, err.message);
          return { instance: inst.id, data: [] };
        })
      )),
      Promise.all(radarrInstances.map(inst =>
        axios.get(`${inst.url}/api/v3/tag`, {
          headers: { 'X-Api-Key': inst.apiKey }
        }).then(res => ({ instance: inst.id, data: res.data })).catch(err => {
          console.error(`[Poller] Radarr ${inst.id} tags error:`, err.message);
          return { instance: inst.id, data: [] };
        })
      )),
      // qBittorrent
      getTorrents().catch(err => {
        console.error(`[Poller] qBittorrent error:`, err.message);
        return [];
      })
    ]);

    // When polling is active, TTL is 3x interval to avoid gaps between polls
    // When polling is disabled (on-demand), use 30s so data refreshes on next request after expiry
    const cacheTTL = POLLING_ENABLED ? POLL_INTERVAL * 3 : 30000;

    // SABnzbd
    const firstSabQueue = sabQueues[0] && sabQueues[0].data && sabQueues[0].data.queue;
    cache.set('poll:sab-queue', {
      slots: sabQueues.flatMap(q => (q.data.queue && q.data.queue.slots) || []),
      status: firstSabQueue && firstSabQueue.status,
      speed: firstSabQueue && firstSabQueue.speed,
      kbpersec: firstSabQueue && firstSabQueue.kbpersec
    }, cacheTTL);

    cache.set('poll:sab-history', {
      slots: sabHistories.flatMap(h => (h.data.history && h.data.history.slots) || [])
    }, cacheTTL);

    // Sonarr
    cache.set('poll:sonarr-tags', sonarrTagsResults, cacheTTL);
    cache.set('poll:sonarr-queue', {
      records: sonarrQueues.flatMap(q => q.data.records || [])
    }, cacheTTL);
    cache.set('poll:sonarr-history', {
      records: sonarrHistories.flatMap(h => h.data.records || [])
    }, cacheTTL);
    cache.set('poll:sonarr-series', sonarrSeriesResults.flatMap(s => {
      const inst = sonarrInstances.find(i => i.id === s.instance);
      return (s.data || []).map(item => ({ ...item, _instanceUrl: inst ? inst.url : null }));
    }), cacheTTL);

    // Radarr
    cache.set('poll:radarr-queue', {
      records: radarrQueues.flatMap(q => q.data.records || [])
    }, cacheTTL);
    cache.set('poll:radarr-history', {
      records: radarrHistories.flatMap(h => h.data.records || [])
    }, cacheTTL);
    cache.set('poll:radarr-movies', radarrMoviesResults.flatMap(m => {
      const inst = radarrInstances.find(i => i.id === m.instance);
      return (m.data || []).map(item => ({ ...item, _instanceUrl: inst ? inst.url : null }));
    }), cacheTTL);
    cache.set('poll:radarr-tags', radarrTagsResults.flatMap(t => t.data || []), cacheTTL);

    // qBittorrent
    cache.set('poll:qbittorrent', qbittorrentTorrents, cacheTTL);

    const elapsed = Date.now() - start;
    console.log(`[Poller] Poll complete in ${elapsed}ms`);
  } catch (err) {
    console.error(`[Poller] Poll error:`, err.message);
  } finally {
    polling = false;
  }
}

let intervalHandle = null;

function startPoller() {
  if (!POLLING_ENABLED) {
    console.log(`[Poller] Background polling disabled (POLL_INTERVAL=${process.env.POLL_INTERVAL || 'not set'}). Data will be fetched on-demand.`);
    return;
  }
  console.log(`[Poller] Starting background poller (interval: ${POLL_INTERVAL}ms)`);
  // Run immediately, then on interval
  pollAllServices();
  intervalHandle = setInterval(pollAllServices, POLL_INTERVAL);
}

function stopPoller() {
  if (intervalHandle) {
    clearInterval(intervalHandle);
    intervalHandle = null;
    console.log('[Poller] Stopped');
  }
}

module.exports = { startPoller, stopPoller, pollAllServices, POLL_INTERVAL, POLLING_ENABLED };