import {z} from 'zod'

export type GetApiProductAvailabilityArgs = {upcs: string, includeVariations?: 1 | undefined};

export type GetApiProductAvailabilityOptions = {baseUrl?: string | undefined, sessionToken?: string | undefined, fetch?: typeof fetch | undefined};

export const productAvailability = z.object({upc: z.string(), quantity: z.number().int().optional(), name: z.string().optional(), merchantId: z.string().optional(), price: z.number().optional(), salePrice: z.number().optional(), image: z.string().optional(), inStock: z.boolean().optional()}).and(z.record(z.string(), z.unknown()));

export const getApiProductAvailabilityResponse = z.array(productAvailability);

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Look up availability for a list of UPCs
 * 
 * GET /product-availability
 */
export const getApiProductAvailability = async (args: GetApiProductAvailabilityArgs, options?: GetApiProductAvailabilityOptions) => {
const {baseUrl = "https://ps.shoppable.com", fetch: fetchFn = fetch, sessionToken} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('accept', "application/json")

if (args.upcs != null) query.append("upcs", String(args.upcs))
if (args.includeVariations != null) query.append("includeVariations", String(args.includeVariations))
if (sessionToken !== undefined) headers.set('authorization', `Bearer ${sessionToken}`)

const url = `${baseUrl.replace(/\/+$/, '')}/product-availability${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "GET", headers})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(getApiProductAvailabilityResponse, await res.json())
};