const DEFAULT_FOILIO_FEED_URL = 'https://foilio.net/api/prices/feed?game=lorcana';

export function getFolioFeedUrl() {
  return process.env.FOILIO_PRICES_FEED_URL ?? DEFAULT_FOILIO_FEED_URL;
}

export function normalizeFolioName(name) {
  return String(name ?? '').trim().toLowerCase().replace(/\s+/g, ' ');
}

function parseAmount(value) {
  if (value == null || value === '') return null;
  const amount = Number(value);
  return Number.isFinite(amount) ? amount : null;
}

/**
 * Parse a Foilio feed row into current/market prices.
 * Prefer USD fields; fall back to EUR with currency noted for snapshots.
 */
export function parseFolioPriceEntry(entry) {
  const usdLow =
    parseAmount(entry.usd_low)
    ?? parseAmount(entry.low_usd)
    ?? parseAmount(entry.price_usd)
    ?? parseAmount(entry.usd);
  const usdMarket =
    parseAmount(entry.usd_market)
    ?? parseAmount(entry.market_usd)
    ?? parseAmount(entry.market)
    ?? parseAmount(entry.price);

  if (usdLow != null || usdMarket != null) {
    return {
      currentPrice: usdLow ?? usdMarket,
      marketPrice: usdMarket ?? usdLow,
      currency: 'USD',
    };
  }

  const eurLow = parseAmount(entry.eur_low) ?? parseAmount(entry.low_eur);
  const eurMarket = parseAmount(entry.eur_market) ?? parseAmount(entry.eur) ?? parseAmount(entry.price_eur);
  if (eurLow != null || eurMarket != null) {
    return {
      currentPrice: eurLow ?? eurMarket,
      marketPrice: eurMarket ?? eurLow,
      currency: 'EUR',
    };
  }

  return { currentPrice: null, marketPrice: null, currency: 'USD' };
}

function feedEntries(payload) {
  if (Array.isArray(payload)) return payload;
  if (Array.isArray(payload?.prices)) return payload.prices;
  if (Array.isArray(payload?.cards)) return payload.cards;
  if (Array.isArray(payload?.data)) return payload.data;
  return [];
}

/**
 * Build lookup indexes from a Foilio feed payload.
 */
export function buildFolioPriceIndex(payload) {
  const byCardId = new Map();
  const byNameSet = new Map();

  for (const entry of feedEntries(payload)) {
    const parsed = parseFolioPriceEntry(entry);
    if (parsed.currentPrice == null && parsed.marketPrice == null) continue;

    const cardId = entry.card_id ?? entry.cardId ?? entry.id ?? entry.unique_id ?? entry.Unique_ID;
    if (cardId) {
      byCardId.set(String(cardId), parsed);
    }

    const setCode = entry.set ?? entry.set_id ?? entry.setId ?? entry.Set_ID;
    const name = entry.name ?? entry.Name;
    if (setCode && name) {
      const key = `${normalizeFolioName(name)}|${String(setCode).trim()}`;
      if (!byNameSet.has(key)) {
        byNameSet.set(key, parsed);
      }
    }
  }

  return { byCardId, byNameSet };
}

/**
 * Match a Lorcana catalog row against the Foilio price index.
 */
export function matchFolioPrice(index, row) {
  const byId = index.byCardId.get(String(row.scryfallId));
  if (byId) return byId;

  const key = `${normalizeFolioName(row.name)}|${String(row.setCode ?? '').trim()}`;
  return index.byNameSet.get(key) ?? null;
}

/**
 * Fetch the Foilio Lorcana price feed once per sync run.
 */
export async function fetchFolioPriceFeed() {
  const response = await fetch(getFolioFeedUrl(), {
    headers: { Accept: 'application/json', 'User-Agent': 'DeckHearth/1.0' },
  });

  if (!response.ok) {
    throw new Error(`Foilio feed error: ${response.status}`);
  }

  return response.json();
}

export async function fetchFolioPriceIndex() {
  const payload = await fetchFolioPriceFeed();
  return buildFolioPriceIndex(payload);
}