import { sql } from '@vercel/postgres';
import { verifyToken } from './auth-utils.js';

// GET /api/user-cards - Get user's cards with optional filters
export default async function handler(req, res) {
  // Set CORS headers
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');

  // Handle preflight requests
  if (req.method === 'OPTIONS') {
    res.status(200).end();
    return;
  }

  if (req.method !== 'GET' && req.method !== 'POST' && req.method !== 'PUT' && req.method !== 'DELETE') {
    return res.status(405).json({ error: 'Method not allowed' });
  }

  try {
    // Temporarily bypass auth for testing
    // const token = req.headers.authorization?.replace('Bearer ', '');
    // const user = await verifyToken(token);
    
    // if (!user) {
    //   return res.status(401).json({ error: 'Unauthorized' });
    // }
    
    const userId = 1; // Temporarily hardcoded for testing
    
    if (req.method === 'GET') {
      const { game, status, page = '1', limit = '20' } = req.query;
      const pageNum = parseInt(page);
      const limitNum = parseInt(limit);
      const offset = (pageNum - 1) * limitNum;
      
      let sqlQuery = `
        SELECT 
          uc.id,
          uc.user_id,
          uc.card_id,
          uc.quantity,
          uc.status,
          uc.condition,
          uc.notes,
          uc.created_at,
          uc.updated_at,
          c.name,
          c.set_name,
          c.set_code,
          c.card_number,
          c.rarity,
          c.game,
          c.mana_cost,
          c.cmc,
          c.card_type,
          c.colors,
          c.oracle_text,
          c.power,
          c.toughness,
          c.image_url,
          c.stock_image_url,
          c.current_price,
          c.market_price,
          c.verified
        FROM user_cards uc
        JOIN cards c ON uc.card_id = c.id
        WHERE uc.user_id = $1
      `;
      
      const params = [userId];
      let paramIndex = 2;
      
      if (game && game !== 'ALL') {
        sqlQuery += ` AND c.game = $${paramIndex}`;
        params.push(game);
        paramIndex++;
      }
      
      if (status && status !== 'ALL') {
        sqlQuery += ` AND uc.status = $${paramIndex}`;
        params.push(status);
        paramIndex++;
      }
      
      sqlQuery += ` ORDER BY c.name ASC LIMIT $${paramIndex} OFFSET $${paramIndex + 1}`;
      params.push(limitNum, offset);
      
      const result = await sql.query(sqlQuery, params);
      
      // Get total count
      let countQuery = `
        SELECT COUNT(*) as total
        FROM user_cards uc
        JOIN cards c ON uc.card_id = c.id
        WHERE uc.user_id = $1
      `;
      
      const countParams = [userId];
      let countParamIndex = 2;
      
      if (game && game !== 'ALL') {
        countQuery += ` AND c.game = $${countParamIndex}`;
        countParams.push(game);
        countParamIndex++;
      }
      
      if (status && status !== 'ALL') {
        countQuery += ` AND uc.status = $${countParamIndex}`;
        countParams.push(status);
        countParamIndex++;
      }
      
      const countResult = await sql.query(countQuery, countParams);
      const total = parseInt(countResult.rows[0].total);
      
      const userCards = result.rows.map(row => ({
        id: row.id,
        userId: row.user_id,
        cardId: row.card_id,
        quantity: row.quantity,
        status: row.status,
        condition: row.condition,
        notes: row.notes,
        createdAt: row.created_at,
        updatedAt: row.updated_at,
        card: {
          id: row.card_id,
          name: row.name,
          setName: row.set_name,
          setCode: row.set_code,
          cardNumber: row.card_number,
          rarity: row.rarity,
          game: row.game,
          manaCost: row.mana_cost,
          cmc: row.cmc,
          cardType: row.card_type,
          colors: row.colors ? JSON.parse(row.colors) : [],
          oracleText: row.oracle_text,
          power: row.power,
          toughness: row.toughness,
          imageUrl: row.image_url,
          stockImageUrl: row.stock_image_url,
          currentPrice: row.current_price,
          marketPrice: row.market_price,
          verified: row.verified
        }
      }));
      
      return res.status(200).json({
        success: true,
        userCards,
        pagination: {
          page: pageNum,
          limit: limitNum,
          total,
          pages: Math.ceil(total / limitNum)
        }
      });
    }
    
    if (req.method === 'POST') {
      const { cardId, quantity = 1, status = 'OWNED', condition = 'NM', notes = '' } = req.body;
      
      if (!cardId) {
        return res.status(400).json({ error: 'Card ID is required' });
      }
      
      // Check if user already has this card
      const existingCard = await sql.query(`
        SELECT * FROM user_cards 
        WHERE user_id = $1 AND card_id = $2
      `, [userId, cardId]);
      
      if (existingCard.rows.length > 0) {
        // Update existing card
        const result = await sql.query(`
          UPDATE user_cards 
          SET quantity = $1, status = $2, condition = $3, notes = $4, updated_at = NOW()
          WHERE user_id = $5 AND card_id = $6
          RETURNING *
        `, [quantity, status, condition, notes, userId, cardId]);
        
        return res.status(200).json({
          success: true,
          message: 'Card updated',
          userCard: result.rows[0]
        });
      } else {
        // Add new card
        const result = await sql.query(`
          INSERT INTO user_cards (user_id, card_id, quantity, status, condition, notes)
          VALUES ($1, $2, $3, $4, $5, $6)
          RETURNING *
        `, [userId, cardId, quantity, status, condition, notes]);
        
        return res.status(201).json({
          success: true,
          message: 'Card added',
          userCard: result.rows[0]
        });
      }
    }
    
    if (req.method === 'PUT') {
      const { id, quantity, status, condition, notes } = req.body;
      
      if (!id) {
        return res.status(400).json({ error: 'User card ID is required' });
      }
      
      const result = await sql.query(`
        UPDATE user_cards 
        SET quantity = COALESCE($1, quantity),
            status = COALESCE($2, status),
            condition = COALESCE($3, condition),
            notes = COALESCE($4, notes),
            updated_at = NOW()
        WHERE id = $5 AND user_id = $6
        RETURNING *
      `, [quantity, status, condition, notes, id, userId]);
      
      if (result.rows.length === 0) {
        return res.status(404).json({ error: 'User card not found' });
      }
      
      return res.status(200).json({
        success: true,
        message: 'Card updated',
        userCard: result.rows[0]
      });
    }
    
    if (req.method === 'DELETE') {
      const { id } = req.query;
      
      if (!id) {
        return res.status(400).json({ error: 'User card ID is required' });
      }
      
      const result = await sql.query(`
        DELETE FROM user_cards 
        WHERE id = $1 AND user_id = $2
        RETURNING *
      `, [id, userId]);
      
      if (result.rows.length === 0) {
        return res.status(404).json({ error: 'User card not found' });
      }
      
      return res.status(200).json({
        success: true,
        message: 'Card removed'
      });
    }
    
  } catch (error) {
    console.error('❌ Error in user-cards API:', error);
    return res.status(500).json({
      error: 'Failed to process user cards request',
      details: error.message
    });
  }
}