import type { Article, Category, CategorySection, Order, Page, Product, ProductDetailSection, StoreSettings } from '@homaroma/types'
import { API_BASE } from './api'

const isDev = process.env.NODE_ENV === 'development'
const defaultRevalidate = 0

type ProductListResponse = {
  data?: Product[]
}

export type Coupon = {
  id: number
  code: string
  type: 'PERCENTAGE' | 'FIXED_AMOUNT' | 'FREE_SHIPPING' | string
  value: number
  minPurchase: number
  usageLimit: number | null
  usedCount: number
  expiresAt?: string | null
}

export type ProductReview = {
  id: number
  rating: number
  comment?: string | null
  customerName?: string | null
  createdAt: string
  customer?: {
    displayName?: string | null
    pictureUrl?: string | null
  } | null
}

export type ApiResult<T> =
  | { ok: true; data: T }
  | { ok: false; error: string; status?: number }

export async function fetchJson<T>(path: string, init?: RequestInit & { next?: { revalidate?: number } }): Promise<T | null> {
  try {
    const res = await fetch(`${API_BASE}${path}`, {
      cache: 'no-store',
      ...init,
      next: init?.next ?? { revalidate: 0 },
    })

    if (!res.ok) {
      console.error(`[website-api] ${path} returned ${res.status}`)
      return null
    }

    return await res.json() as T
  } catch (error) {
    console.error(`[website-api] Failed to fetch ${path}`, error)
    return null
  }
}

export async function fetchJsonResult<T>(path: string, init?: RequestInit & { next?: { revalidate?: number } }): Promise<ApiResult<T>> {
  try {
    const res = await fetch(`${API_BASE}${path}`, {
      cache: 'no-store',
      ...init,
      next: init?.next ?? { revalidate: 0 },
    })

    if (!res.ok) {
      return { ok: false, error: `${path} returned ${res.status}`, status: res.status }
    }

    return { ok: true, data: await res.json() as T }
  } catch (error) {
    return {
      ok: false,
      error: error instanceof Error ? error.message : `Failed to fetch ${path}`,
    }
  }
}

export async function getCategories(lang = 'all'): Promise<Category[]> {
  return await fetchJson<Category[]>(`/categories?lang=${lang}`, { next: { revalidate: 0 } }) ?? []
}

export async function getCategoriesResult(lang = 'all'): Promise<ApiResult<Category[]>> {
  return await fetchJsonResult<Category[]>(`/categories?lang=${lang}`, { next: { revalidate: 0 } })
}

export async function getStoreSettings(lang = 'all'): Promise<StoreSettings | null> {
  return await fetchJson<StoreSettings>(`/settings?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getStoreSettingsResult(lang = 'all'): Promise<ApiResult<StoreSettings>> {
  return await fetchJsonResult<StoreSettings>(`/settings?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getCmsPage(slug: string, lang = 'all'): Promise<Page | null> {
  return await fetchJson<Page>(`/pages/${slug}?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getCmsPageResult(slug: string, lang = 'all'): Promise<ApiResult<Page>> {
  return await fetchJsonResult<Page>(`/pages/${slug}?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getArticlesResult(): Promise<ApiResult<Article[]>> {
  return await fetchJsonResult<Article[]>('/articles?publishedOnly=true', { next: { revalidate: defaultRevalidate } })
}

export async function getActiveCouponsResult(): Promise<ApiResult<Coupon[]>> {
  const response = await fetchJsonResult<Coupon[]>('/coupons/active', { next: { revalidate: defaultRevalidate } })
  if (!response.ok) return response

  return {
    ok: true,
    data: response.data.filter((coupon) => coupon.usageLimit === null || coupon.usedCount < coupon.usageLimit),
  }
}

export async function getOrderResult(id: string | number, lang = 'all'): Promise<ApiResult<Order>> {
  const query = lang && lang !== 'all' ? `?lang=${lang}` : ''
  return await fetchJsonResult<Order>(`/orders/${id}${query}`, { next: { revalidate: defaultRevalidate } })
}

export async function getProduct(id: string | number, lang = 'all'): Promise<Product | null> {
  return await fetchJson<Product>(`/products/${id}?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getProductResult(id: string | number, lang = 'all'): Promise<ApiResult<Product>> {
  return await fetchJsonResult<Product>(`/products/${id}?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getProductDetailSectionsResult(id: string | number, lang = 'all'): Promise<ApiResult<ProductDetailSection[]>> {
  return await fetchJsonResult<ProductDetailSection[]>(`/products/${id}/detail-sections?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getCategorySectionsResult(id: string | number, lang = 'all'): Promise<ApiResult<CategorySection[]>> {
  return await fetchJsonResult<CategorySection[]>(`/categories/${id}/sections?lang=${lang}`, { next: { revalidate: defaultRevalidate } })
}

export async function getProductReviewsResult(id: string | number): Promise<ApiResult<ProductReview[]>> {
  return await fetchJsonResult<ProductReview[]>(`/reviews/product/${id}`, { next: { revalidate: defaultRevalidate } })
}

export async function getProducts(query = '', lang = 'all'): Promise<Product[]> {
  const separator = query ? '&' : ''
  const response = await fetchJson<ProductListResponse>(`/products?${query}${separator}lang=${lang}`, {
    next: { revalidate: defaultRevalidate },
  })

  return response?.data ?? []
}

export async function getProductsResult(query = '', lang = 'all'): Promise<ApiResult<Product[]>> {
  const separator = query ? '&' : ''
  const response = await fetchJsonResult<ProductListResponse>(`/products?${query}${separator}lang=${lang}`, {
    next: { revalidate: defaultRevalidate },
  })

  if (!response.ok) return response
  return { ok: true, data: response.data.data ?? [] }
}