import Redis from 'ioredis';
import { sql } from '../sql.js';
import { isPriceStale } from './card-price.js';
import { buildOutboundLinks } from './outbound-links.js';
import { recordPriceSnapshots } from './price-history.js';
import { getTcgdexBaseUrl, parseTcgdexPricing } from './tcgdex-client.js';
import { fetchFolioPriceIndex, matchFolioPrice } from './foolio-client.js';

const REFRESH_LOCK_TTL_SEC = 60;
const REFRESH_LOCK_PREFIX = 'deckhearth:pricing-refresh:';

let redisClient = null;

function getRedis() {
  const url = process.env.REDIS_URL;
  if (!url) return null;
  if (!redisClient) {
    redisClient = new Redis(url, {
      maxRetriesPerRequest: 1,
      enableOfflineQueue: false,
    });
  }
  return redisClient;
}

/**
 * @param {number} cardId
 * @returns {Promise<boolean>}
 */
async function acquireRefreshLock(cardId) {
  const redis = getRedis();
  if (!redis) return true;
  try {
    const result = await redis.set(
      `${REFRESH_LOCK_PREFIX}${cardId}`,
      '1',
      'EX',
      REFRESH_LOCK_TTL_SEC,
      'NX'
    );
    return result === 'OK';
  } catch (err) {
    console.error('[pricing-service] lock acquire failed', err);
    return false;
  }
}

/**
 * @param {number} cardId
 */
async function releaseRefreshLock(cardId) {
  const redis = getRedis();
  if (!redis) return;
  try {
    await redis.del(`${REFRESH_LOCK_PREFIX}${cardId}`);
  } catch (err) {
    console.error('[pricing-service] lock release failed', err);
  }
}

/**
 * @param {string} scryfallId
 */
async function fetchScryfallPrices(scryfallId) {
  const response = await fetch(`https://api.scryfall.com/cards/${scryfallId}`, {
    headers: { 'User-Agent': 'DeckHearth/1.0', Accept: 'application/json' },
  });
  if (!response.ok) {
    throw new Error(`Scryfall API error: ${response.status}`);
  }
  const card = await response.json();
  let currentPrice = null;
  let marketPrice = null;
  if (card.prices) {
    currentPrice = card.prices.usd ? parseFloat(card.prices.usd) : null;
    marketPrice = card.prices.usd_foil ? parseFloat(card.prices.usd_foil) : null;
  }
  return { currentPrice, marketPrice, currency: 'USD' };
}

/**
 * @param {{ set_code?: string, card_number?: string, name?: string }} card
 */
async function fetchPokemonPrices(card) {
  const setCode = card.set_code;
  if (!setCode) return null;

  const base = getTcgdexBaseUrl();
  if (!card.card_number) return null;

  const paths = [
    `/cards/${encodeURIComponent(setCode)}-${encodeURIComponent(card.card_number)}`,
  ];

  for (const path of paths) {
    try {
      const response = await fetch(`${base}${path}`, {
        headers: { Accept: 'application/json', 'User-Agent': 'DeckHearth/1.0' },
      });
      if (!response.ok) continue;
      const tcgCard = await response.json();
      const parsed = parseTcgdexPricing(tcgCard);
      if (parsed.currentPrice != null || parsed.marketPrice != null) {
        return {
          currentPrice: parsed.currentPrice,
          marketPrice: parsed.marketPrice,
          currency: parsed.currency ?? 'USD',
        };
      }
    } catch {
      // try next path
    }
  }

  return null;
}

/**
 * @param {{ name?: string, set_code?: string, scryfall_id?: string }} card
 */
async function fetchLorcanaPrices(card) {
  const index = await fetchFolioPriceIndex();
  const matched = matchFolioPrice(index, {
    name: card.name,
    setCode: card.set_code,
    scryfallId: card.scryfall_id,
  });
  if (!matched) return null;
  return {
    currentPrice: matched.currentPrice,
    marketPrice: matched.marketPrice,
    currency: matched.currency ?? 'USD',
  };
}

/**
 * @param {Record<string, unknown>} card
 */
async function refreshLivePrices(card) {
  const game = String(card.game || '').toLowerCase();
  let prices = null;

  if (game === 'mtg' && card.scryfall_id) {
    prices = await fetchScryfallPrices(card.scryfall_id);
  } else if (game === 'pokemon') {
    prices = await fetchPokemonPrices(card);
  } else if (game === 'lorcana') {
    prices = await fetchLorcanaPrices(card);
  }

  if (!prices || (prices.currentPrice == null && prices.marketPrice == null)) {
    return null;
  }

  await sql`
    UPDATE cards
    SET
      current_price = ${prices.currentPrice},
      market_price = ${prices.marketPrice},
      prices_updated_at = CURRENT_TIMESTAMP,
      updated_at = CURRENT_TIMESTAMP
    WHERE id = ${card.id}
  `;

  const snapshots = [];
  if (prices.currentPrice != null) {
    snapshots.push({
      cardId: card.id,
      source: game === 'mtg' ? 'scryfall' : game === 'pokemon' ? 'tcgdex' : 'foilio',
      priceType: 'market',
      currency: prices.currency ?? 'USD',
      amount: prices.currentPrice,
    });
  }
  if (prices.marketPrice != null && prices.marketPrice !== prices.currentPrice) {
    snapshots.push({
      cardId: card.id,
      source: game === 'mtg' ? 'scryfall' : game === 'pokemon' ? 'tcgdex' : 'foilio',
      priceType: 'foil',
      currency: prices.currency ?? 'USD',
      amount: prices.marketPrice,
    });
  }
  if (snapshots.length) {
    await recordPriceSnapshots(snapshots);
  }

  return prices;
}

/**
 * @param {number} cardId
 * @returns {Promise<null | {
 *   prices: { current: number | null, market: number | null, currency: string },
 *   pricesUpdatedAt: string | null,
 *   stale: boolean,
 *   outbound: { tcgplayer: string, ebay: string },
 * }>}
 */
export async function getCardPricing(cardId) {
  const result = await sql`
    SELECT
      id, name, game, set_name, set_code, card_number,
      current_price, market_price, prices_updated_at, scryfall_id
    FROM cards
    WHERE id = ${cardId}
  `;

  if (result.rows.length === 0) {
    return null;
  }

  let card = result.rows[0];
  let stale = isPriceStale(card.prices_updated_at);

  if (stale) {
    const gotLock = await acquireRefreshLock(cardId);
    if (gotLock) {
      try {
        await refreshLivePrices(card).catch((err) => {
          console.error('[pricing-service] live refresh failed', err);
        });

        const refreshed = await sql`
          SELECT
            id, name, game, set_name, set_code, card_number,
            current_price, market_price, prices_updated_at, scryfall_id
          FROM cards
          WHERE id = ${cardId}
        `;
        if (refreshed.rows.length) {
          card = refreshed.rows[0];
          stale = isPriceStale(card.prices_updated_at);
        }
      } finally {
        await releaseRefreshLock(cardId);
      }
    }
  }

  const current = card.current_price != null ? parseFloat(card.current_price) : null;
  const market = card.market_price != null ? parseFloat(card.market_price) : null;

  return {
    prices: {
      current: Number.isFinite(current) ? current : null,
      market: Number.isFinite(market) ? market : null,
      currency: 'USD',
    },
    pricesUpdatedAt: card.prices_updated_at
      ? new Date(card.prices_updated_at).toISOString()
      : null,
    stale,
    outbound: buildOutboundLinks(card),
  };
}