import type { Category, Product, Brand } from '@/types/api';

interface CmsPage {
  id: string;
  slug: string;
  title: string;
  body: string;
  status: string;
}

const BASE = process.env.NEXT_PUBLIC_API_URL ?? 'http://127.0.0.1:3000';

export async function fetchCategories(): Promise<Category[]> {
  const res = await fetch(`${BASE}/categories/tree`);
  if (!res.ok) throw new Error(`Failed to fetch categories: ${res.status}`);
  const data = await res.json();
  return data.items ?? [];
}

export async function fetchProducts(params?: {
  limit?: number;
  offset?: number;
  q?: string;
  categorySlug?: string;
  brandSlug?: string;
}): Promise<Product[]> {
  const sp = new URLSearchParams();
  sp.set('limit', String(params?.limit ?? 8));
  if (params?.offset !== undefined) sp.set('offset', String(params.offset));
  if (params?.q) sp.set('q', params.q);
  if (params?.categorySlug) sp.set('categorySlug', params.categorySlug);
  if (params?.brandSlug) sp.set('brandSlug', params.brandSlug);
  const res = await fetch(`${BASE}/products/search?${sp}`, { credentials: 'include' });
  if (!res.ok) throw new Error(`Failed to fetch products: ${res.status}`);
  const data = await res.json();
  return data.items ?? [];
}

export async function fetchSearchSuggestions(term: string): Promise<string[]> {
  const sp = new URLSearchParams({ q: term });
  const res = await fetch(`${BASE}/products/suggest?${sp}`, {
    cache: 'no-store',
    credentials: 'include',
  });
  if (!res.ok) return [];
  const data = await res.json();
  return data.suggestions ?? [];
}

export async function fetchBrandBySlug(slug: string): Promise<Brand | null> {
  const res = await fetch(`${BASE}/marca/${slug}`);
  if (res.status === 404) return null;
  if (!res.ok) throw new Error(`Failed to fetch brand: ${res.status}`);
  return res.json();
}

export async function fetchPage(slug: string): Promise<CmsPage | null> {
  const res = await fetch(`${BASE}/cms/pages/${slug}`);
  if (res.status === 404) return null;
  if (!res.ok) throw new Error(`Failed to fetch page: ${res.status}`);
  return res.json();
}

export async function fetchBrands(): Promise<Brand[]> {
  const res = await fetch(`${BASE}/brands`);
  if (!res.ok) throw new Error(`Failed to fetch brands: ${res.status}`);
  const data = await res.json();
  return data.items ?? [];
}

export async function fetchCategoryBySlug(slug: string): Promise<Category | null> {
  const res = await fetch(`${BASE}/categoria/${slug}`);
  if (res.status === 404) return null;
  if (!res.ok) throw new Error(`Failed to fetch category: ${res.status}`);
  return res.json();
}

export async function fetchProductBySlug(slug: string): Promise<Product | null> {
  const res = await fetch(`${BASE}/productos/${slug}`);
  if (res.status === 404) return null;
  if (!res.ok) throw new Error(`Failed to fetch product: ${res.status}`);
  return res.json();
}

export interface ProductVariant {
  id: string;
  productId: string;
  sku: string;
  ean: string | null;
  attributes: Record<string, unknown>;
  weightGrams: number | null; // F-193
}

export interface VariantPrice {
  variantId: string;
  netUnitAmountCents: number;
  vatRate: 'general' | 'reduced';
  currency: string;
}

export interface StockAvailability {
  available: boolean;
  availableQuantity: number;
}

export async function fetchProductVariants(productId: string): Promise<ProductVariant[]> {
  const res = await fetch(`${BASE}/products/${productId}/variants`);
  if (!res.ok) throw new Error(`Failed to fetch variants: ${res.status}`);
  const data = await res.json();
  return data.items ?? [];
}

export async function fetchVariantPrice(variantId: string): Promise<VariantPrice | null> {
  const res = await fetch(`${BASE}/pricing/variants/${variantId}`);
  if (res.status === 404) return null;
  if (!res.ok) throw new Error(`Failed to fetch price: ${res.status}`);
  return res.json();
}

export async function fetchStockAvailability(variantId: string): Promise<StockAvailability> {
  const res = await fetch(`${BASE}/inventory/${variantId}/availability`);
  if (!res.ok) throw new Error(`Failed to fetch stock: ${res.status}`);
  return res.json();
}

export function formatPrice(cents: number): string {
  return `€${(cents / 100).toFixed(2)}`;
}

export function calcGrossPrice(netCents: number, vatRate: 'general' | 'reduced'): number {
  const rate = vatRate === 'general' ? 0.21 : 0.1;
  return Math.round(netCents * (1 + rate));
}