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

const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

function pokemonHeaders() {
  const headers = {
    'User-Agent': 'Deck-Hearth/1.0',
    Accept: 'application/json',
  };
  if (process.env.POKEMON_TCG_API_KEY) {
    headers['X-Api-Key'] = process.env.POKEMON_TCG_API_KEY;
  }
  return headers;
}

export async function fetchWithRetry(url, maxRetries = 3, delayMs = 2000) {
  for (let attempt = 1; attempt <= maxRetries; attempt += 1) {
    try {
      const response = await fetch(url, { headers: pokemonHeaders() });

      if (response.ok) {
        return response;
      }

      if (response.status === 404) {
        throw new Error(`Resource not found: ${response.status}`);
      }

      if (response.status === 504 || response.status === 503) {
        console.log(
          `[fetchWithRetry] Attempt ${attempt}: ${response.status}, retrying in ${delayMs * attempt}ms`
        );
        await delay(delayMs * attempt);
        continue;
      }

      throw new Error(`Pokemon TCG API error: ${response.status}`);
    } catch (error) {
      if (attempt === maxRetries) {
        throw error;
      }
      console.log(`[fetchWithRetry] Attempt ${attempt} failed:`, error.message);
      await delay(delayMs * attempt);
    }
  }

  throw new Error('fetchWithRetry exhausted retries');
}

/**
 * Import all cards for a Pokémon TCG set id. Skips rows already present by scryfall_id
 * (legacy column name stores Pokémon TCG API card ids too).
 */
export async function importPokemonSet(setCode) {
  const response = await fetchWithRetry(
    `https://api.pokemontcg.io/v2/cards?q=set.id:${setCode}&pageSize=250`
  );

  const data = await response.json();
  const cards = data.data || [];

  if (cards.length === 0) {
    return { setCode, imported: 0, skipped: 0, total: 0 };
  }

  let imported = 0;
  let skipped = 0;

  for (const card of cards) {
    try {
      const existingCard = await sql`
        SELECT id FROM cards WHERE scryfall_id = ${card.id}
      `;

      if (existingCard.rows.length > 0) {
        skipped += 1;
        continue;
      }

      let currentPrice = null;
      if (card.tcgplayer?.prices?.normal?.market) {
        currentPrice = parseFloat(card.tcgplayer.prices.normal.market);
      } else if (card.tcgplayer?.prices?.holofoil?.market) {
        currentPrice = parseFloat(card.tcgplayer.prices.holofoil.market);
      }

      let rarity = card.rarity || 'Unknown';
      if (rarity.includes('Holo')) {
        rarity = 'Holographic';
      } else if (rarity.includes('Secret')) {
        rarity = 'Secret Rare';
      } else if (rarity.includes('Ultra')) {
        rarity = 'Ultra Rare';
      }

      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}, 'Pokemon', null, null, ${card.supertype || 'Pokemon'},
          ${JSON.stringify(card.types || [])}, ${card.flavorText || null},
          ${card.attacks?.[0]?.damage || null}, null,
          ${card.images?.small || null}, ${card.images?.large || null},
          ${currentPrice}, null, ${card.id}, true
        )
      `;

      imported += 1;
    } catch (error) {
      console.error(`[importPokemonSet] Error importing card ${card.name}:`, error);
      skipped += 1;
    }
  }

  return { setCode, imported, skipped, total: cards.length };
}

export { pokemonHeaders };