/**
 * Findagram API Client
 *
 * Connects to the backend /api/v1/* public endpoints.
 * Uses REACT_APP_API_URL environment variable for the base URL.
 *
 * Local development: http://localhost:3010
 * Production: https://cannaiq.co (shared API backend)
 */

const API_BASE_URL = process.env.REACT_APP_API_URL || '';

/**
 * Make a fetch request to the API
 */
async function request(endpoint, options = {}) {
  const url = `${API_BASE_URL}${endpoint}`;

  const response = await fetch(url, {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      ...options.headers,
    },
  });

  if (!response.ok) {
    const error = await response.json().catch(() => ({ error: 'Request failed' }));
    throw new Error(error.error || `HTTP ${response.status}`);
  }

  return response.json();
}

/**
 * Build query string from params object
 */
function buildQueryString(params) {
  const filtered = Object.entries(params).filter(([_, v]) => v !== undefined && v !== null && v !== '');
  if (filtered.length === 0) return '';
  return '?' + new URLSearchParams(filtered).toString();
}

// ============================================================
// PRODUCTS
// ============================================================

/**
 * Search/filter products across all dispensaries
 *
 * @param {Object} params
 * @param {string} [params.search] - Search term (name or brand)
 * @param {string} [params.type] - Category type (flower, concentrates, edibles, etc.)
 * @param {string} [params.subcategory] - Subcategory
 * @param {string} [params.brandName] - Brand name filter
 * @param {string} [params.stockStatus] - Stock status (in_stock, out_of_stock, unknown)
 * @param {number} [params.storeId] - Filter to specific store
 * @param {number} [params.limit=50] - Page size
 * @param {number} [params.offset=0] - Offset for pagination
 */
export async function getProducts(params = {}) {
  const queryString = buildQueryString({
    search: params.search,
    type: params.type,
    subcategory: params.subcategory,
    brandName: params.brandName,
    stockStatus: params.stockStatus,
    storeId: params.storeId,
    limit: params.limit || 50,
    offset: params.offset || 0,
  });

  return request(`/api/v1/products${queryString}`);
}

/**
 * Get a single product by ID
 */
export async function getProduct(id) {
  return request(`/api/v1/products/${id}`);
}

/**
 * Get product availability - which dispensaries carry this product
 *
 * @param {number|string} productId - Product ID
 * @param {Object} params
 * @param {number} params.lat - User latitude
 * @param {number} params.lng - User longitude
 * @param {number} [params.maxRadiusMiles=50] - Maximum search radius in miles
 * @returns {Promise<{productId: number, productName: string, brandName: string, totalCount: number, offers: Array}>}
 */
export async function getProductAvailability(productId, params = {}) {
  const { lat, lng, maxRadiusMiles = 50 } = params;

  if (!lat || !lng) {
    throw new Error('lat and lng are required');
  }

  const queryString = buildQueryString({
    lat,
    lng,
    max_radius_miles: maxRadiusMiles,
  });

  return request(`/api/v1/products/${productId}/availability${queryString}`);
}

/**
 * Get similar products (same brand + category)
 *
 * @param {number|string} productId - Product ID
 * @returns {Promise<{similarProducts: Array<{productId: number, name: string, brandName: string, imageUrl: string, price: number}>}>}
 */
export async function getSimilarProducts(productId) {
  return request(`/api/v1/products/${productId}/similar`);
}

/**
 * Get products for a specific store with filters
 */
export async function getStoreProducts(storeId, params = {}) {
  const queryString = buildQueryString({
    search: params.search,
    type: params.type,
    subcategory: params.subcategory,
    brandName: params.brandName,
    stockStatus: params.stockStatus,
    limit: params.limit || 50,
    offset: params.offset || 0,
  });

  return request(`/api/v1/dispensaries/${storeId}/products${queryString}`);
}

// ============================================================
// DISPENSARIES (STORES)
// ============================================================

/**
 * Get all dispensaries
 *
 * @param {Object} params
 * @param {string} [params.city] - Filter by city
 * @param {boolean} [params.hasPlatformId] - Filter by platform ID presence
 * @param {number} [params.limit=100] - Page size
 * @param {number} [params.offset=0] - Offset
 */
export async function getDispensaries(params = {}) {
  const queryString = buildQueryString({
    city: params.city,
    state: params.state,
    hasPlatformId: params.hasPlatformId,
    has_products: params.hasProducts ? 'true' : undefined,
    limit: params.limit || 100,
    offset: params.offset || 0,
  });

  return request(`/api/v1/dispensaries${queryString}`);
}

/**
 * Get a single dispensary by ID
 */
export async function getDispensary(id) {
  return request(`/api/v1/dispensaries/${id}`);
}

/**
 * Get dispensary by slug or platform ID
 */
export async function getDispensaryBySlug(slug) {
  return request(`/api/v1/dispensaries/slug/${slug}`);
}

/**
 * Get dispensary summary (product counts, categories, brands)
 */
export async function getDispensarySummary(id) {
  return request(`/api/v1/dispensaries/${id}/summary`);
}

/**
 * Get brands available at a specific dispensary
 */
export async function getDispensaryBrands(id) {
  return request(`/api/v1/dispensaries/${id}/brands`);
}

/**
 * Get categories available at a specific dispensary
 */
export async function getDispensaryCategories(id) {
  return request(`/api/v1/dispensaries/${id}/categories`);
}

// ============================================================
// CATEGORIES
// ============================================================

/**
 * Get all categories with product counts
 */
export async function getCategories() {
  return request('/api/v1/categories');
}

// ============================================================
// BRANDS
// ============================================================

/**
 * Get all brands with product counts
 *
 * @param {Object} params
 * @param {number} [params.limit=100] - Page size
 * @param {number} [params.offset=0] - Offset
 */
export async function getBrands(params = {}) {
  const queryString = buildQueryString({
    limit: params.limit || 100,
    offset: params.offset || 0,
  });

  return request(`/api/v1/brands${queryString}`);
}

// ============================================================
// STATS
// ============================================================

/**
 * Get aggregate stats (product count, brand count, dispensary count)
 */
export async function getStats() {
  return request('/api/v1/stats');
}

// ============================================================
// DEALS / SPECIALS
// ============================================================

/**
 * Get products on special/sale
 * Uses the on_special filter parameter on the products endpoint
 *
 * @param {Object} params
 * @param {string} [params.type] - Category type filter
 * @param {string} [params.brandName] - Brand name filter
 * @param {number} [params.limit=100] - Page size
 * @param {number} [params.offset=0] - Offset for pagination
 */
export async function getSpecials(params = {}) {
  const queryString = buildQueryString({
    on_special: 'true',
    type: params.type,
    brandName: params.brandName,
    stockStatus: params.stockStatus || 'in_stock',
    limit: params.limit || 100,
    offset: params.offset || 0,
  });

  return request(`/api/v1/products${queryString}`);
}

/**
 * Alias for getSpecials for backward compatibility
 */
export async function getDeals(params = {}) {
  return getSpecials(params);
}

// ============================================================
// SEARCH (convenience wrapper)
// ============================================================

/**
 * Search products by term
 */
export async function searchProducts(searchTerm, params = {}) {
  return getProducts({
    ...params,
    search: searchTerm,
  });
}

// ============================================================
// FIELD MAPPING HELPERS
// ============================================================

/**
 * Map API product to UI-compatible format
 * Backend returns snake_case, UI expects camelCase with specific field names
 *
 * @param {Object} apiProduct - Product from API
 * @returns {Object} - Product formatted for UI components
 */
export function mapProductForUI(apiProduct) {
  // Handle both direct product and transformed product formats
  const p = apiProduct;

  // Helper to parse price (API returns strings like "29.99" or null)
  const parsePrice = (val) => {
    if (val === null || val === undefined) return null;
    const num = typeof val === 'string' ? parseFloat(val) : val;
    return isNaN(num) ? null : num;
  };

  const regularPrice = parsePrice(p.regular_price);
  const salePrice = parsePrice(p.sale_price);
  const medPrice = parsePrice(p.med_price);
  const medSalePrice = parsePrice(p.med_sale_price);
  const regularPriceMax = parsePrice(p.regular_price_max);

  return {
    id: p.id,
    name: p.name,
    brand: p.brand || p.brand_name,
    category: p.type || p.category || p.category_raw,
    subcategory: p.subcategory || p.subcategory_raw,
    strainType: p.strain_type || null,
    // Images
    image: p.image_url || p.primary_image_url || null,
    // Potency
    thc: p.thc_percentage || p.thc_content || null,
    cbd: p.cbd_percentage || p.cbd_content || null,
    // Prices (parsed to numbers)
    price: regularPrice,
    priceRange: regularPriceMax && regularPrice
      ? { min: regularPrice, max: regularPriceMax }
      : null,
    onSale: !!(salePrice || medSalePrice),
    salePrice: salePrice,
    medPrice: medPrice,
    medSalePrice: medSalePrice,
    // Stock
    inStock: p.in_stock !== undefined ? p.in_stock : p.stock_status === 'in_stock',
    stockStatus: p.stock_status,
    // Store info (if available)
    storeName: p.store_name,
    storeCity: p.store_city,
    storeSlug: p.store_slug,
    dispensaryId: p.dispensary_id,
    // Options/variants
    options: p.options,
    totalQuantity: p.total_quantity,
    // Timestamps
    updatedAt: p.updated_at || p.snapshot_at,
    // For compatibility with ProductCard expectations
    rating: null, // Not available from API
    reviewCount: null, // Not available from API
    dispensaries: [], // Not populated in list view
    dispensaryCount: p.store_name ? 1 : 0,
  };
}

/**
 * Map API category to UI-compatible format
 */
export function mapCategoryForUI(apiCategory) {
  return {
    id: apiCategory.type,
    name: formatCategoryName(apiCategory.type),
    slug: apiCategory.type?.toLowerCase().replace(/\s+/g, '-'),
    subcategory: apiCategory.subcategory,
    productCount: parseInt(apiCategory.product_count || 0, 10),
    dispensaryCount: parseInt(apiCategory.dispensary_count || 0, 10),
    brandCount: parseInt(apiCategory.brand_count || 0, 10),
  };
}

/**
 * Map API brand to UI-compatible format
 */
export function mapBrandForUI(apiBrand) {
  // API returns 'brand' field (see /api/v1/brands endpoint)
  const brandName = apiBrand.brand || apiBrand.brand_name || '';
  return {
    id: brandName,
    name: brandName,
    slug: brandName ? brandName.toLowerCase().replace(/\s+/g, '-') : '',
    logo: apiBrand.brand_logo_url || null,
    productCount: parseInt(apiBrand.product_count || 0, 10),
    dispensaryCount: parseInt(apiBrand.dispensary_count || 0, 10),
    productTypes: apiBrand.product_types || [],
  };
}

/**
 * Map API dispensary to UI-compatible format
 */
export function mapDispensaryForUI(apiDispensary) {
  // Handle location object from API (location.latitude, location.longitude)
  const lat = apiDispensary.location?.latitude || apiDispensary.latitude;
  const lng = apiDispensary.location?.longitude || apiDispensary.longitude;

  return {
    id: apiDispensary.id,
    name: apiDispensary.dba_name || apiDispensary.name,
    slug: apiDispensary.slug,
    city: apiDispensary.city,
    state: apiDispensary.state,
    address: apiDispensary.address1 || apiDispensary.address,
    zip: apiDispensary.zip,
    latitude: lat,
    longitude: lng,
    website: apiDispensary.website,
    menuUrl: apiDispensary.menu_url,
    imageUrl: apiDispensary.image_url,
    rating: apiDispensary.rating,
    reviewCount: apiDispensary.review_count,
    // Product data from API
    productCount: apiDispensary.product_count || apiDispensary.totalProducts || 0,
    inStockCount: apiDispensary.in_stock_count || apiDispensary.inStockCount || 0,
    brandCount: apiDispensary.brandCount,
    categoryCount: apiDispensary.categoryCount,
    // Services
    services: apiDispensary.services || {
      pickup: false,
      delivery: false,
      curbside: false
    },
    // License type
    licenseType: apiDispensary.license_type || {
      medical: false,
      recreational: false
    },
  };
}

/**
 * Format category name for display
 */
function formatCategoryName(type) {
  if (!type) return '';
  // Convert "FLOWER" to "Flower", "PRE_ROLLS" to "Pre Rolls", etc.
  return type
    .toLowerCase()
    .replace(/_/g, ' ')
    .replace(/\b\w/g, c => c.toUpperCase());
}

// ============================================================
// CLICK TRACKING
// ============================================================

/**
 * Get cached visitor location from sessionStorage
 */
function getCachedVisitorLocation() {
  try {
    const cached = sessionStorage.getItem('findagram_location');
    if (cached) {
      return JSON.parse(cached);
    }
  } catch (err) {
    // Ignore errors
  }
  return null;
}

/**
 * Track a product click event
 * Fire-and-forget - doesn't block UI
 *
 * @param {Object} params
 * @param {string} params.productId - Product ID (required)
 * @param {string} [params.storeId] - Store/dispensary ID
 * @param {string} [params.brandId] - Brand name/ID
 * @param {string} [params.dispensaryName] - Dispensary name
 * @param {string} params.action - Action type: view, open_product, open_store, compare
 * @param {string} params.source - Source identifier (e.g., 'findagram')
 * @param {string} [params.pageType] - Page type (e.g., 'home', 'dispensary', 'deals')
 */
export function trackProductClick(params) {
  // Get visitor's cached location
  const visitorLocation = getCachedVisitorLocation();

  const payload = {
    product_id: String(params.productId),
    store_id: params.storeId ? String(params.storeId) : undefined,
    brand_id: params.brandId || undefined,
    dispensary_name: params.dispensaryName || undefined,
    action: params.action || 'view',
    source: params.source || 'findagram',
    page_type: params.pageType || undefined,
    url_path: window.location.pathname,
    // Visitor location from IP geolocation
    visitor_city: visitorLocation?.city || undefined,
    visitor_state: visitorLocation?.state || undefined,
    visitor_lat: visitorLocation?.lat || undefined,
    visitor_lng: visitorLocation?.lng || undefined,
  };

  // Fire and forget - don't await
  fetch(`${API_BASE_URL}/api/events/product-click`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(payload),
  }).catch(() => {
    // Silently ignore errors - analytics shouldn't break UX
  });
}

// Default export for convenience
const api = {
  // Products
  getProducts,
  getProduct,
  getProductAvailability,
  getSimilarProducts,
  getStoreProducts,
  searchProducts,
  // Dispensaries
  getDispensaries,
  getDispensary,
  getDispensaryBySlug,
  getDispensarySummary,
  getDispensaryBrands,
  getDispensaryCategories,
  // Categories & Brands
  getCategories,
  getBrands,
  // Stats
  getStats,
  // Deals
  getDeals,
  getSpecials,
  // Mappers
  mapProductForUI,
  mapCategoryForUI,
  mapBrandForUI,
  mapDispensaryForUI,
  // Tracking
  trackProductClick,
};

export default api;