const { Pool } = require('pg');
const jwt = require('jsonwebtoken');

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  ssl: process.env.NODE_ENV === 'production' ? { rejectUnauthorized: false } : false,
});

// Middleware to verify user authentication
function verifyAuth(req) {
  const authHeader = req.headers.authorization;
  if (!authHeader || !authHeader.startsWith('Bearer ')) {
    throw new Error('No token provided');
  }

  const token = authHeader.substring(7);
  const jwtSecret = process.env.JWT_SECRET || 'fallback-secret-change-in-production';
  
  try {
    const decoded = jwt.verify(token, jwtSecret);
    return decoded;
  } catch (error) {
    throw new Error('Invalid token');
  }
}

export default async function handler(req, res) {
  if (req.method !== 'POST') {
    return res.status(405).json({ error: 'Method not allowed' });
  }

  const client = await pool.connect();
  
  try {
    // Verify authentication
    const user = verifyAuth(req);

    const { 
      name,
      game,
      setName = null,
      setCode = null,
      rarity = null,
      cardType = null,
      manaCost = null,
      ocrConfidence = null,
      ocrRawText = null,
      imageUrl = null
    } = req.body;

    // Validate required fields
    if (!name || !game) {
      return res.status(400).json({ 
        error: 'Card name and game are required' 
      });
    }

    // Try to find existing card first
    let searchQuery = `
      SELECT id, name, set_name, set_code, rarity, game, card_type, mana_cost, 
             current_price, stock_image_url, image_url, verified
      FROM cards 
      WHERE LOWER(name) = LOWER($1) AND UPPER(game) = UPPER($2)
    `;
    
    let searchParams = [name.trim(), game.trim()];

    // If set name is provided, try to match more specifically
    if (setName) {
      searchQuery += ` AND (set_name IS NULL OR LOWER(set_name) = LOWER($3))`;
      searchParams.push(setName.trim());
    }

    searchQuery += ` ORDER BY verified DESC, created_at DESC LIMIT 1`;

    const existingCard = await client.query(searchQuery, searchParams);

    if (existingCard.rows.length > 0) {
      // Card found, return it
      const card = existingCard.rows[0];
      
      res.status(200).json({
        success: true,
        found: true,
        message: 'Card found in database',
        card: {
          id: card.id,
          name: card.name,
          setName: card.set_name,
          setCode: card.set_code,
          rarity: card.rarity,
          game: card.game,
          cardType: card.card_type,
          manaCost: card.mana_cost,
          currentPrice: card.current_price,
          stockImageUrl: card.stock_image_url,
          imageUrl: card.image_url,
          verified: card.verified
        }
      });
    } else {
      // Card not found, create new one
      const insertQuery = `
        INSERT INTO cards (
          name, game, set_name, set_code, rarity, card_type, mana_cost,
          ocr_confidence, ocr_raw_text, image_url, verified, created_at, updated_at
        ) VALUES (
          $1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP
        )
        RETURNING id, name, set_name, set_code, rarity, game, card_type, mana_cost, 
                  ocr_confidence, ocr_raw_text, image_url, verified, created_at
      `;

      const insertParams = [
        name.trim(),
        game.trim().toUpperCase(),
        setName?.trim() || null,
        setCode?.trim() || null,
        rarity?.trim() || null,
        cardType?.trim() || null,
        manaCost?.trim() || null,
        ocrConfidence || null,
        ocrRawText?.trim() || null,
        imageUrl?.trim() || null,
        false // New cards from OCR are unverified by default
      ];

      const newCard = await client.query(insertQuery, insertParams);
      const card = newCard.rows[0];

      res.status(201).json({
        success: true,
        found: false,
        message: 'New card created from scan data',
        card: {
          id: card.id,
          name: card.name,
          setName: card.set_name,
          setCode: card.set_code,
          rarity: card.rarity,
          game: card.game,
          cardType: card.card_type,
          manaCost: card.mana_cost,
          currentPrice: null,
          stockImageUrl: null,
          imageUrl: card.image_url,
          verified: card.verified,
          ocrConfidence: card.ocr_confidence,
          ocrRawText: card.ocr_raw_text,
          createdAt: card.created_at
        }
      });
    }

  } catch (error) {
    console.error('Find or create card error:', error);
    
    if (error.message === 'No token provided' || error.message === 'Invalid token') {
      res.status(401).json({ error: error.message });
    } else {
      res.status(500).json({ 
        error: 'Internal server error',
        details: error.message 
      });
    }
  } finally {
    client.release();
  }
}