import { createHash } from 'node:crypto';

import { sql } from '../sql.js';
import { geocodeUsZip } from './nominatim.js';
import { fetchGameStores } from './overpass.js';

export const STORES_CACHE_TTL_MS = 7 * 24 * 60 * 60 * 1000;

/**
 * @param {number} lat
 * @param {number} lng
 * @param {number} radiusMeters
 * @returns {string}
 */
export function buildStoresCacheKey(lat, lng, radiusMeters) {
  const payload = `${lat.toFixed(5)}:${lng.toFixed(5)}:${radiusMeters}`;
  return createHash('sha256').update(payload).digest('hex').slice(0, 64);
}

/**
 * @param {Date | string | null | undefined} fetchedAt
 * @param {number} [ttlMs]
 * @returns {boolean}
 */
export function isStoresCacheFresh(fetchedAt, ttlMs = STORES_CACHE_TTL_MS) {
  if (!fetchedAt) return false;
  const ts = fetchedAt instanceof Date ? fetchedAt.getTime() : new Date(fetchedAt).getTime();
  if (!Number.isFinite(ts)) return false;
  return Date.now() - ts < ttlMs;
}

/**
 * @param {string} zip
 * @param {{ fetchImpl?: typeof fetch }} [options]
 * @returns {Promise<{ lat: number, lng: number, displayName: string, cached: boolean } | null>}
 */
export async function getZipCoords(zip, options = {}) {
  const cached = await sql`
    SELECT lat, lng, display_name
    FROM geo_zip_cache
    WHERE zip = ${zip}
    LIMIT 1
  `;

  if (cached.rows.length > 0) {
    const row = cached.rows[0];
    return {
      lat: Number(row.lat),
      lng: Number(row.lng),
      displayName: row.display_name ?? zip,
      cached: true,
    };
  }

  const geocoded = await geocodeUsZip(zip, options);
  if (!geocoded) {
    return null;
  }

  await sql`
    INSERT INTO geo_zip_cache (zip, lat, lng, display_name)
    VALUES (${zip}, ${geocoded.lat}, ${geocoded.lng}, ${geocoded.displayName})
    ON CONFLICT (zip) DO UPDATE SET
      lat = EXCLUDED.lat,
      lng = EXCLUDED.lng,
      display_name = EXCLUDED.display_name,
      geocoded_at = CURRENT_TIMESTAMP
  `;

  return { ...geocoded, cached: false };
}

/**
 * @param {number} lat
 * @param {number} lng
 * @param {number} radiusMeters
 * @param {{ fetchImpl?: typeof fetch, forceRefresh?: boolean }} [options]
 * @returns {Promise<{ stores: unknown[], cached: boolean }>}
 */
export async function getStoresNear(lat, lng, radiusMeters, options = {}) {
  const cacheKey = buildStoresCacheKey(lat, lng, radiusMeters);

  if (!options.forceRefresh) {
    const cached = await sql`
      SELECT stores, fetched_at
      FROM geo_stores_cache
      WHERE cache_key = ${cacheKey}
      LIMIT 1
    `;

    if (cached.rows.length > 0 && isStoresCacheFresh(cached.rows[0].fetched_at)) {
      return { stores: cached.rows[0].stores, cached: true };
    }
  }

  const stores = await fetchGameStores(lat, lng, radiusMeters, options);

  await sql`
    INSERT INTO geo_stores_cache (cache_key, lat, lng, radius_meters, stores, fetched_at)
    VALUES (${cacheKey}, ${lat}, ${lng}, ${radiusMeters}, ${JSON.stringify(stores)}::jsonb, CURRENT_TIMESTAMP)
    ON CONFLICT (cache_key) DO UPDATE SET
      lat = EXCLUDED.lat,
      lng = EXCLUDED.lng,
      radius_meters = EXCLUDED.radius_meters,
      stores = EXCLUDED.stores,
      fetched_at = CURRENT_TIMESTAMP
  `;

  return { stores, cached: false };
}