// src/controllers/review.controller.js
const Review = require('../models/Review');
const Media = require('../models/Media');
const User = require('../models/User');

// --- Helper: Recalculate Average Rating ---
// We run this every time a review is added. 
// It uses MongoDB's math engine to average the scores instantly.
const updateMediaStats = async (mediaId) => {
  const stats = await Review.aggregate([
    { $match: { mediaId: mediaId } },
    {
      $group: {
        _id: '$mediaId',
        avgRating: { $avg: '$rating' },
        reviewCount: { $sum: 1 }
      }
    }
  ]);

  if (stats.length > 0) {
    await Media.findByIdAndUpdate(mediaId, {
      'brutaleStats.avgRating': stats[0].avgRating.toFixed(1),
      'brutaleStats.reviewCount': stats[0].reviewCount
    });
  }
};

// --- 1. POST: Create Review ---
exports.createReview = async (req, res) => {
  try {
    const { mediaId, rating, content, guestName } = req.body;

    // COERCE isSpoiler safely
    const isSpoiler = (() => {
      const val = req.body.isSpoiler;
      if (typeof val === 'boolean') return val;
      if (typeof val === 'string') return val === 'true';
      return false;
    })();

    const userId = req.user ? req.user.id : null;

    // A. Validation
    if (!mediaId || !rating || !content) {
      return res.status(400).json({ error: 'Missing required fields' });
    }

    // --- NEW: load username for logged-in user ---
    let finalGuestName = guestName;   // default for guests

    if (userId) {
      const user = await User.findById(userId).select("username");
      finalGuestName = user.username; // overwrite guestName
    } else {
      finalGuestName = guestName || "Anonymous Brutalist";
    }

    // B. Anti-Spam
    const tenMinutesAgo = new Date(Date.now() - 10 * 60 * 1000);
    const duplicateCheck = await Review.findOne({
      mediaId,
      $or: [
        { userId: userId },
        { guestName: finalGuestName }
      ],
      createdAt: { $gte: tenMinutesAgo }
    });

    if (duplicateCheck) {
      return res.status(429).json({ error: 'Chill! You just reviewed this. Wait 10 mins.' });
    }

    // C. Build Review
    const reviewData = {
      mediaId,
      userId,
      rating,
      content,
      isSpoiler,
      guestName: finalGuestName,      // <-- ALWAYS included
      slangTags: []
    };

    const newReview = await Review.create(reviewData);

    // D. Update user stats
    if (userId) {
      await User.findByIdAndUpdate(userId, { $inc: { 'stats.reviewsCount': 1 } });
    }

    // E. Update media stats
    updateMediaStats(mediaId);

    res.status(201).json(newReview);

  } catch (error) {
    console.error('Review Error:', error);
    res.status(500).json({ error: 'Server crashed processing your review.' });
  }
};


// --- 2. GET: Fetch Reviews ---
exports.getReviews = async (req, res) => {
  try {
    const { mediaId } = req.params;
    const page = parseInt(req.query.page) || 1;
    const limit = 10;

    const reviews = await Review.find({ mediaId })
      .populate('userId', 'username honestyScore badges') // Get author details
      .sort({ createdAt: -1 }) // Newest first
      .skip((page - 1) * limit)
      .limit(limit);

    res.json(reviews);
  } catch (error) {
    res.status(500).json({ error: 'Failed to fetch reviews' });
  }
};

// --- 3. GET: Reviews by User ---
exports.getReviewsByUser = async (req, res) => {
  try {
    const { userId } = req.params;

    const reviews = await Review.find({ userId })
      .populate('mediaId', 'title posterPath type') // bring media info
      .sort({ createdAt: -1 });

    res.json(reviews);

  } catch (error) {
    console.error("User Review Fetch Error:", error);
    res.status(500).json({ error: 'Failed to fetch user review history' });
  }
};

// -------------------
exports.addReply = async (req, res) => {
  try {
    const { id } = req.params; // Review ID
    const { content, guestName } = req.body;
    const userId = req.user ? req.user.id : null;

    if (!content) return res.status(400).json({ error: 'Content required' });

    // 1. Find Review
    const review = await Review.findById(id);
    if (!review) return res.status(404).json({ error: 'Review not found' });

    // 2. Determine reply name
    let finalGuestName;

    if (userId) {
      const user = await User.findById(userId).select("username");
      finalGuestName = user.username;     // logged in user = username
    } else {
      finalGuestName = guestName || "Anonymous Brutalist";  // guest user
    }

    // 3. Build reply object
    const newReply = {
      content,
      userId: userId || null,
      guestName: finalGuestName
    };

    // 4. Add reply and save
    review.replies.push(newReply);
    await review.save();

    // 5. Populate username immediately
    await review.populate("replies.userId", "username");

    // 6. Get the reply we just pushed
    let added = review.replies[review.replies.length - 1];

    // Normalize shape for frontend (safe, clean)
    const normalizedReply = {
      _id: added._id,
      content: added.content,
      createdAt: added.createdAt,
      username: added.userId ? added.userId.username : added.guestName,
      userId: added.userId?._id || null
    };

    res.status(201).json(normalizedReply);

  } catch (error) {
    console.error("Reply Error:", error);
    res.status(500).json({ error: 'Failed to add reply' });
  }
};