/**
 * Wishlist Controller - User favorites/saved destinations
 */
const { getPool } = require('../db');

/**
 * Get user's wishlist
 */
async function listWishlist(req, res) {
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  const userId = req.user.id || req.user.sub;
  
  try {
    // Create table if not exists
    await pool.query(`
      CREATE TABLE IF NOT EXISTS wishlists (
        id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
        user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
        destination_id TEXT NOT NULL,
        created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
        UNIQUE(user_id, destination_id)
      )
    `);
    
    const result = await pool.query(
      `SELECT w.id, w.destination_id, w.created_at,
              d.name, d.slug, d.description, d.category, d.district, d.rating
       FROM wishlists w
       LEFT JOIN destinations d ON w.destination_id = d.id
       WHERE w.user_id = $1
       ORDER BY w.created_at DESC`,
      [userId]
    );
    
    res.json({ 
      success: true, 
      wishlist: result.rows.map(row => ({
        id: row.id,
        destinationId: row.destination_id,
        createdAt: row.created_at,
        destination: row.name ? {
          id: row.destination_id,
          name: row.name,
          slug: row.slug,
          description: row.description,
          category: row.category,
          district: row.district,
          rating: row.rating
        } : null
      }))
    });
  } catch (error) {
    console.error('[Wishlist List Error]', error.message);
    res.status(500).json({ error: 'Failed to fetch wishlist' });
  }
}

/**
 * Add item to wishlist
 */
async function addToWishlist(req, res) {
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  const userId = req.user.id || req.user.sub;
  const { destination_id } = req.body;
  
  if (!destination_id) {
    return res.status(400).json({ error: 'destination_id is required' });
  }
  
  try {
    // Create table if not exists
    await pool.query(`
      CREATE TABLE IF NOT EXISTS wishlists (
        id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
        user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
        destination_id TEXT NOT NULL,
        created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
        UNIQUE(user_id, destination_id)
      )
    `);
    
    const result = await pool.query(
      `INSERT INTO wishlists (user_id, destination_id)
       VALUES ($1, $2)
       ON CONFLICT (user_id, destination_id) DO NOTHING
       RETURNING id, destination_id, created_at`,
      [userId, destination_id]
    );
    
    if (result.rows.length === 0) {
      return res.json({ success: true, message: 'Already in wishlist' });
    }
    
    res.status(201).json({ 
      success: true, 
      message: 'Added to wishlist',
      item: result.rows[0]
    });
  } catch (error) {
    console.error('[Wishlist Add Error]', error.message);
    res.status(500).json({ error: 'Failed to add to wishlist' });
  }
}

/**
 * Remove item from wishlist
 */
async function removeFromWishlist(req, res) {
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  const userId = req.user.id || req.user.sub;
  const { destinationId } = req.params;
  
  try {
    const result = await pool.query(
      'DELETE FROM wishlists WHERE user_id = $1 AND destination_id = $2 RETURNING id',
      [userId, destinationId]
    );
    
    if (result.rows.length === 0) {
      return res.status(404).json({ error: 'Item not found in wishlist' });
    }
    
    res.json({ success: true, message: 'Removed from wishlist' });
  } catch (error) {
    console.error('[Wishlist Remove Error]', error.message);
    res.status(500).json({ error: 'Failed to remove from wishlist' });
  }
}

/**
 * Check if destination is in wishlist
 */
async function checkWishlist(req, res) {
  const pool = getPool();
  if (!pool) return res.status(500).json({ error: 'Database not connected' });
  
  const userId = req.user.id || req.user.sub;
  const { destinationId } = req.params;
  
  try {
    // Create table if not exists (to prevent 500 if checked before any add)
    await pool.query(`
      CREATE TABLE IF NOT EXISTS wishlists (
        id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
        user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
        destination_id TEXT NOT NULL,
        created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
        UNIQUE(user_id, destination_id)
      )
    `);

    const result = await pool.query(
      'SELECT id FROM wishlists WHERE user_id = $1 AND destination_id = $2',
      [userId, destinationId]
    );
    
    res.json({ 
      success: true, 
      inWishlist: result.rows.length > 0 
    });
  } catch (error) {
    console.error('[Wishlist Check Error]', error.message);
    res.status(500).json({ error: 'Failed to check wishlist' });
  }
}

module.exports = {
  listWishlist,
  addToWishlist,
  removeFromWishlist,
  checkWishlist
};