import { sql } from '@vercel/postgres';

// Helper function to delay execution
const delay = (ms) => new Promise(resolve => setTimeout(resolve, ms));

// Helper function to fetch with retry logic
async function fetchWithRetry(url, maxRetries = 3, delayMs = 2000) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      const response = await fetch(url, {
        headers: {
          'User-Agent': 'TCG-Vault/1.0',
          'Accept': 'application/json'
        },
        timeout: 30000 // 30 second timeout
      });
      
      if (response.ok) {
        return response;
      }
      
      // If it's a 404, don't retry
      if (response.status === 404) {
        throw new Error(`Set not found: ${response.status}`);
      }
      
      // If it's a 504 or 503, wait longer before retry
      if (response.status === 504 || response.status === 503) {
        console.log(`Attempt ${attempt}: Got ${response.status}, waiting ${delayMs * attempt}ms before retry...`);
        await delay(delayMs * attempt);
        continue;
      }
      
      throw new Error(`Lorcana API error: ${response.status}`);
    } catch (error) {
      if (attempt === maxRetries) {
        throw error;
      }
      console.log(`Attempt ${attempt} failed:`, error.message);
      await delay(delayMs * attempt);
    }
  }
}

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

  try {
    const { setCode } = req.body;
    
    if (!setCode) {
      return res.status(400).json({ error: 'Set code is required' });
    }

    console.log(`Starting import for Lorcana set: ${setCode}`);

    // For now, we'll use a placeholder approach since Lorcana doesn't have a public API
    // You can replace this with actual Lorcana API calls when available
    const mockCards = [
      {
        id: `lorcana-${setCode}-001`,
        name: 'Sample Lorcana Card',
        set: { name: setCode, id: setCode },
        number: '001',
        rarity: 'Common',
        supertype: 'Character',
        types: ['Character'],
        flavorText: 'A sample Lorcana card',
        images: { small: null, large: null }
      }
    ];

    console.log(`Using mock data for set ${setCode} (${mockCards.length} cards)`);

    let importedCount = 0;
    let skippedCount = 0;

    for (const card of mockCards) {
      try {
        // Check if card already exists
        const existingCard = await sql`
          SELECT id FROM cards WHERE scryfall_id = ${card.id}
        `;

        if (existingCard.rows.length > 0) {
          skippedCount++;
          continue;
        }

        // Determine rarity
        let rarity = card.rarity || 'Common';
        if (rarity.includes('Enchanted')) {
          rarity = 'Enchanted';
        } else if (rarity.includes('Legendary')) {
          rarity = 'Legendary';
        } else if (rarity.includes('Rare')) {
          rarity = 'Rare';
        }

        // Insert card into database
        await sql`
          INSERT INTO cards (
            name, set_name, set_code, card_number, rarity, game,
            mana_cost, cmc, card_type, colors, oracle_text,
            power, toughness, image_url, stock_image_url,
            current_price, market_price, scryfall_id, verified
          ) VALUES (
            ${card.name}, ${card.set.name}, ${card.set.id}, ${card.number},
            ${rarity}, 'Lorcana', null, null, ${card.supertype || 'Character'},
            ${JSON.stringify(card.types || [])}, ${card.flavorText || null},
            null, null,
            ${card.images?.small || null}, ${card.images?.large || null},
            null, null, ${card.id}, true
          )
        `;

        importedCount++;
      } catch (error) {
        console.error(`Error importing card ${card.name}:`, error);
        skippedCount++;
      }
    }

    console.log(`Import completed for set ${setCode}: ${importedCount} imported, ${skippedCount} skipped`);

    res.status(200).json({
      success: true,
      message: `Import completed for set ${setCode}`,
      imported: importedCount,
      skipped: skippedCount,
      total: mockCards.length
    });

  } catch (error) {
    console.error('Card import error:', error);
    res.status(500).json({ 
      error: 'Import failed', 
      details: error.message 
    });
  }
}