const api = require('./api');
const fetch = require('node-fetch');

// Twitch API credentials (optional). If provided, we'll enrich embeds with user bio.
const twitchClientId = process.env.TWITCH_CLIENT_ID || null;
const twitchClientSecret = process.env.TWITCH_CLIENT_SECRET || null;
let twitchAppToken = null; // cached app access token
let twitchTokenExpires = 0;

// Cache of user login -> { description, profile_image_url, fetchedAt }
const userInfoCache = new Map();

async function getAppToken() {
  if (!twitchClientId || !twitchClientSecret) return null;
  const now = Date.now();
  if (twitchAppToken && now < twitchTokenExpires - 60000) { // refresh 1 min early
    return twitchAppToken;
  }
  try {
    const res = await fetch(`https://id.twitch.tv/oauth2/token?client_id=${twitchClientId}&client_secret=${twitchClientSecret}&grant_type=client_credentials`, { method: 'POST' });
    const json = await res.json();
    twitchAppToken = json.access_token;
    twitchTokenExpires = now + (json.expires_in * 1000);
    return twitchAppToken;
  } catch (e) {
    console.error('Failed to fetch Twitch app token:', e && e.message ? e.message : e);
    return null;
  }
}

async function fetchUserInfo(login) {
  if (!login) return null;
  const lower = login.toLowerCase();
  const cached = userInfoCache.get(lower);
  const now = Date.now();
  if (cached && now - cached.fetchedAt < 1000 * 60 * 30) { // 30 min cache
    return cached;
  }
  const token = await getAppToken();
  if (!token) return null;
  try {
    const res = await fetch(`https://api.twitch.tv/helix/users?login=${encodeURIComponent(lower)}`, {
      headers: {
        'Client-ID': twitchClientId,
        'Authorization': `Bearer ${token}`
      }
    });
    const json = await res.json();
    const data = (json.data && json.data[0]) || null;
    if (data) {
      const info = { description: data.description || '', profile_image_url: data.profile_image_url || '', fetchedAt: now };
      userInfoCache.set(lower, info);
      return info;
    }
  } catch (e) {
    console.error('Failed to fetch Twitch user info for', lower, e && e.message ? e.message : e);
  }
  return null;
}

let polling = false;
const pollIntervalMs = Number(process.env.TWITCH_POLL_INTERVAL_MS || 5000); // 5s default

// Keep track of which streams we've already announced per guild:user -> { started_at }
const announced = new Map(); // key: `${guildId}:${user}` -> { started_at }

async function checkGuild(client, guild) {
  try {
    // Intentionally quiet: per-guild checking logs are suppressed to avoid spam
    const settings = await api.getServerSettings(guild.id) || {};
    const liveSettings = settings.liveNotifications || {};
    if (!liveSettings.enabled) return;
    const channelId = liveSettings.channelId;
    const users = (liveSettings.users || []).map(u => u.toLowerCase()).filter(Boolean);
    if (!channelId || users.length === 0) return;
    // ask backend for current live streams
    const query = users.join(',');
    const streams = await api._rawGetTwitchStreams ? api._rawGetTwitchStreams(query) : null;
    // If the helper isn't available, try backend proxy
    let live = [];
    if (streams) live = streams.filter(s => s.is_live);
    else {
      try {
        const resp = await api.tryFetchTwitchStreams(query);
        live = (resp || []).filter(s => s.is_live);
      } catch (e) {
        live = [];
      }
    }
    if (!live || live.length === 0) {
      // No live streams: ensure any announced keys for these users are cleared so they can be re-announced later
      for (const u of users) {
        const key = `${guild.id}:${u}`;
        if (announced.has(key)) {
          announced.delete(key);
        }
      }
      return;
    }


    // fetch channel using client to ensure we can reach it
    let channel = null;
    try {
      channel = await client.channels.fetch(channelId);
      if (channel.type !== 0) { // 0 is text channel
        console.error(`TwitchWatcher: channel ${channelId} is not a text channel (type: ${channel.type})`);
        channel = null;
      }
    } catch (e) {
      console.error(`TwitchWatcher: failed to fetch channel ${channelId}:`, e && e.message ? e.message : e);
      channel = null;
    }
    if (!channel) {
      // Channel not found or inaccessible; skip
      return;
    }

    // Build a map of live logins for quick lookup
    const liveLogins = new Set(live.map(s => (s.user_login || '').toLowerCase()));

    // Clear announced entries for users that are no longer live
    for (const u of users) {
      const key = `${guild.id}:${u}`;
      if (!liveLogins.has(u) && announced.has(key)) {
        announced.delete(key);
      }
    }

    // Announce each live once per live session
    for (const s of live) {
      const login = (s.user_login || '').toLowerCase();
      const key = `${guild.id}:${login}`;
      if (announced.has(key)) continue; // already announced for this live session
      // mark announced for this session
      announced.set(key, { started_at: s.started_at || new Date().toISOString() });

      // Build and send embed (standardized layout)
      try {
        // Announce without per-guild log spam
        const { EmbedBuilder } = require('discord.js');
        // Attempt to enrich with user bio (description) if available
        let bio = '';
        try {
          const info = await fetchUserInfo(login);
          if (info && info.description) bio = info.description.slice(0, 200);
        } catch (_) {}
        const embed = new EmbedBuilder()
          .setColor(0x9146FF)
          .setTitle(s.title || `${s.user_name} is live`)
          .setURL(s.url)
          .setAuthor({ name: s.user_name, iconURL: s.profile_image_url || undefined, url: s.url })
          .setThumbnail(s.thumbnail_url || s.profile_image_url || undefined)
          .addFields(
            { name: 'Category', value: s.game_name || 'Unknown', inline: true },
            { name: 'Viewers', value: String(s.viewer_count || 0), inline: true }
          )
          .setDescription(bio || (s.description || '').slice(0, 200))
          .setFooter({ text: `ehchadservices • Started: ${s.started_at ? new Date(s.started_at).toLocaleString() : 'unknown'}` });

        // Determine message text (custom overrides default). Provide a plain text prefix if available.
        let prefixMsg = '';
        if (liveSettings.customMessage) {
          prefixMsg = liveSettings.customMessage;
        } else if (liveSettings.message) {
          prefixMsg = liveSettings.message;
        } else {
          prefixMsg = `🔴 ${s.user_name} is now live!`;
        }
        // Ensure we always hyperlink the title via embed; prefix is optional add above embed
        const payload = prefixMsg ? { content: prefixMsg, embeds: [embed] } : { embeds: [embed] };
        await channel.send(payload);
        console.log(`🔔 Announced live: ${login} - ${(s.title || '').slice(0, 80)}`);
      } catch (e) {
        console.error(`TwitchWatcher: failed to send announcement for ${login}:`, e && e.message ? e.message : e);
        // fallback
        const msg = `🔴 ${s.user_name} is live: **${s.title}**\nWatch: ${s.url}`;
        try { await channel.send({ content: msg }); console.log('TwitchWatcher: fallback message sent'); } catch (err) { console.error('TwitchWatcher: fallback send failed:', err && err.message ? err.message : err); }
      }
    }
  } catch (e) {
    console.error('Error checking guild for live streams:', e && e.message ? e.message : e);
  }
}

async function poll(client) {
  if (polling) return;
  polling = true;
  console.log(`🔁 TwitchWatcher started, polling every ${Math.round(pollIntervalMs/1000)}s`);
  // Initial check on restart: send messages for currently live users
  try {
    const guilds = Array.from(client.guilds.cache.values());
    for (const g of guilds) {
      await checkGuild(client, g).catch(err => { console.error('TwitchWatcher: initial checkGuild error', err && err.message ? err.message : err); });
    }
  } catch (e) {
    console.error('Error during initial twitch check:', e && e.message ? e.message : e);
  }
  while (polling) {
    try {
      const guilds = Array.from(client.guilds.cache.values());
      for (const g of guilds) {
        await checkGuild(client, g).catch(err => { console.error('TwitchWatcher: checkGuild error', err && err.message ? err.message : err); });
      }
    } catch (e) {
      console.error('Error during twitch poll loop:', e && e.message ? e.message : e);
    }
    await new Promise(r => setTimeout(r, pollIntervalMs));
  }
}

function stop() { polling = false; }

module.exports = { poll, stop };