// Copyright (c) 2026 Gordon Bolton. MIT License.
/**
 * Pure filter / sort / search utilities for Ombi requests.
 * Must stay in sync with client/src/utils/ombiFilters.js
 */

/**
 * Derive a single status string from an Ombi request object.
 * Priority: available > denied > approved > pending > unknown
 *
 * @param {Object} request
 * @returns {string} 'available' | 'denied' | 'approved' | 'pending' | 'unknown'
 */
function getRequestStatus(request) {
  if (!request) return 'unknown';
  if (request.available) return 'available';
  if (request.denied) return 'denied';
  if (request.approved) return 'approved';
  if (request.requested) return 'pending';

  // Ombi TV requests store status flags inside childRequests
  if (Array.isArray(request.childRequests) && request.childRequests.length > 0) {
    for (const child of request.childRequests) {
      if (child && child.available) return 'available';
    }
    for (const child of request.childRequests) {
      if (child && child.denied) return 'denied';
    }
    for (const child of request.childRequests) {
      if (child && child.approved) return 'approved';
    }
    for (const child of request.childRequests) {
      if (child && child.requested) return 'pending';
    }
  }

  return 'unknown';
}

/**
 * Filter requests by media type.
 *
 * @param {Array} requests
 * @param {string[]} types - e.g. ['movie', 'tv'] or ['all']
 * @returns {Array}
 */
function filterByType(requests, types) {
  if (!types || types.length === 0) return requests;
  const normalized = types.map(t => t.toLowerCase());
  if (normalized.includes('all')) return requests;
  return requests.filter(r => normalized.includes(r.mediaType));
}

/**
 * Filter requests by status.
 *
 * @param {Array} requests
 * @param {string[]} statuses - e.g. ['pending', 'approved', 'available', 'denied']
 * @returns {Array}
 */
function filterByStatus(requests, statuses) {
  if (!statuses || statuses.length === 0) return requests;
  const normalized = statuses.map(s => s.toLowerCase());
  return requests.filter(r => normalized.includes(getRequestStatus(r)));
}

/**
 * Filter requests by case-insensitive title substring.
 *
 * @param {Array} requests
 * @param {string} query
 * @returns {Array}
 */
function filterBySearch(requests, query) {
  if (!query || query.trim() === '') return requests;
  const q = query.trim().toLowerCase();
  return requests.filter(r => (r.title || '').toLowerCase().includes(q));
}

/**
 * Sort requests by the given sort mode.
 *
 * @param {Array} requests
 * @param {string} sortMode - requestedDate_desc | requestedDate_asc | title_asc | title_desc
 * @returns {Array} new sorted array
 */
function sortRequests(requests, sortMode) {
  const sorted = [...requests];
  switch (sortMode) {
    case 'requestedDate_asc':
      return sorted.sort((a, b) => {
        const da = a.requestedDate ? new Date(a.requestedDate).getTime() : 0;
        const db = b.requestedDate ? new Date(b.requestedDate).getTime() : 0;
        return da - db;
      });
    case 'title_asc':
      return sorted.sort((a, b) => (a.title || '').localeCompare(b.title || ''));
    case 'title_desc':
      return sorted.sort((a, b) => (b.title || '').localeCompare(a.title || ''));
    case 'requestedDate_desc':
    default:
      return sorted.sort((a, b) => {
        const da = a.requestedDate ? new Date(a.requestedDate).getTime() : 0;
        const db = b.requestedDate ? new Date(b.requestedDate).getTime() : 0;
        return db - da;
      });
  }
}

/**
 * Apply all filters and sorting in one call.
 *
 * @param {Array} requests
 * @param {Object} options
 * @param {string[]} options.types
 * @param {string[]} options.statuses
 * @param {string} options.sort
 * @param {string} options.search
 * @returns {Array}
 */
function applyRequestFilters(requests, { types, statuses, sort, search } = {}) {
  let result = [...requests];
  result = filterByType(result, types);
  result = filterByStatus(result, statuses);
  result = filterBySearch(result, search);
  result = sortRequests(result, sort);
  return result;
}

module.exports = {
  getRequestStatus,
  filterByType,
  filterByStatus,
  filterBySearch,
  sortRequests,
  applyRequestFilters
};