const axios = require('axios');
const Media = require('../models/Media');

// 1. GET TRENDING (Lazy Sync: Fetch TMDB -> Save DB -> Return)
exports.getTrending = async (req, res) => {
  try {
    // Fetch from TMDB
    const response = await axios.get(`https://api.themoviedb.org/3/trending/all/day`, {
      params: { 
        api_key: process.env.TMDB_KEY,
        region: 'IN' 
      }
    });

    const trendingItems = [];

    // Process results
    for (const item of response.data.results) {
      // Skip incomplete data or people
      if (item.media_type === 'person') continue;

      const releaseDate = item.release_date || item.first_air_date;
      const tmdbId = item.id.toString();

      // Prepare object for DB
      const mediaData = {
        tmdbId: tmdbId,
        title: item.title || item.name,
        type: item.media_type,
        posterPath: item.poster_path,
        backdropPath: item.backdrop_path,
        releaseDate: releaseDate ? new Date(releaseDate) : null,
        overview: item.overview,
        brutaleStats: {popularity : item.popularity, avgRating: item.vote_average, voteCount: item.vote_count},
      };

      // Upsert into DB (Update if exists, Insert if new)
      const updatedMedia = await Media.findOneAndUpdate(
        { tmdbId: tmdbId },
        mediaData,
        { upsert: true, new: true, setDefaultsOnInsert: true }
      );

      trendingItems.push(updatedMedia);
    }

    res.json(trendingItems);

  } catch (error) {
    console.error("Trending Error:", error.message);
    res.status(500).json({ error: 'Failed to fetch trending content' });
  }
};

exports.getPopular = async (req, res) => {
  try {
    const page = req.query.page || 1;

    // Fetch from TMDB
    const response = await axios.get(`https://api.themoviedb.org/3/movie/popular`, {
      params: { 
        api_key: process.env.TMDB_KEY,
        page,
        region: "IN"
      }
    });

    const popularItems = [];

    for (const item of response.data.results) {
      const tmdbId = item.id.toString();

      const mediaData = {
        tmdbId: tmdbId,
        title: item.title,
        type: 'movie',
        posterPath: item.poster_path,
        backdropPath: item.backdrop_path,
        releaseDate: item.release_date ? new Date(item.release_date) : null,
        overview: item.overview,
        brutaleStats: {
          popularity: item.popularity,
          avgRating: item.vote_average?.toFixed(1) || "0.0",
          voteCount: item.vote_count
        }
      };

      // Upsert into DB (Insert if new, update if existing)
      const updatedMedia = await Media.findOneAndUpdate(
        { tmdbId: tmdbId },
        mediaData,
        { upsert: true, new: true, setDefaultsOnInsert: true }
      );

      popularItems.push(updatedMedia);
    }

    res.json(popularItems);

  } catch (error) {
    console.error("Popular Error:", error.message);
    res.status(500).json({ error: "Failed to fetch popular movies" });
  }
};

// 2. GET DETAILS
exports.getMediaDetails = async (req, res) => {
  try {
    const { id } = req.params; // This is the TMDB ID passed from URL

    // Try finding in DB first
    let media = await Media.findOne({ tmdbId: id });

    // If not in DB, fetch from TMDB and save
    if (!media) {
      // We need to know if it's a movie or tv show. 
      // For this simplified version, we might need to try both or rely on the query param.
      // BUT, usually the user clicks from the homepage where we already saved it.
      // Let's try fetching as movie first, then TV as fallback.
      try {
        const tmdbRes = await axios.get(`https://api.themoviedb.org/3/movie/${id}`, {
          params: { api_key: process.env.TMDB_KEY }
        });
        const item = tmdbRes.data;
        media = await Media.create({
          tmdbId: item.id.toString(),
          title: item.title,
          type: 'movie',
          posterPath: item.poster_path,
          backdropPath: item.backdrop_path,
          releaseDate: item.release_date,
          overview: item.overview
        });
      } catch (err) {
        // Try TV
        const tmdbResTv = await axios.get(`https://api.themoviedb.org/3/tv/${id}`, {
          params: { api_key: process.env.TMDB_KEY }
        });
        const item = tmdbResTv.data;
        media = await Media.create({
          tmdbId: item.id.toString(),
          title: item.name,
          type: 'tv',
          posterPath: item.poster_path,
          backdropPath: item.backdrop_path,
          releaseDate: item.first_air_date,
          overview: item.overview
        });
      }
    }

    if (!media) return res.status(404).json({ error: 'Media not found' });
    res.json(media);

  } catch (error) {
    console.error("Details Error:", error.message);
    res.status(404).json({ error: 'Media not found on TMDB or DB' });
  }
};

// 3. SEARCH (Hybrid)
exports.searchMedia = async (req, res) => {
  const query = req.query.q;
  if (!query) return res.json([]);

  try {
    // Search DB (using text index created in Schema)
    // Note: Ensure you created the index in MongoDB Atlas or via Schema: MediaSchema.index({ title: 'text' });
    let results = await Media.find(
      { $text: { $search: query } },
      { score: { $meta: "textScore" } }
    ).sort({ score: { $meta: "textScore" } }).limit(10);

    // If few results, fetch TMDB
    if (results.length < 5) {
      const tmdbRes = await axios.get(`https://api.themoviedb.org/3/search/multi`, {
        params: { api_key: process.env.TMDB_KEY, query: query }
      });

      const tmdbItems = tmdbRes.data.results
        .filter(item => (item.media_type === 'movie' || item.media_type === 'tv') && item.poster_path)
        .map(item => ({
          tmdbId: item.id.toString(),
          title: item.title || item.name,
          posterPath: item.poster_path,
          type: item.media_type,
          releaseDate: item.release_date || item.first_air_date,
          // Temporary object structure for frontend
          brutaleStats: { avgRating: 0 }
        }));
      
      // Merge results (prevent duplicates)
      const existingIds = new Set(results.map(r => r.tmdbId));
      const newItems = tmdbItems.filter(i => !existingIds.has(i.tmdbId));
      results = [...results, ...newItems];
    }

    res.json(results);
  } catch (error) {
    res.status(500).json({ error: 'Search failed' });
  }
};