import {z} from 'zod'

export type TransportMode = 'parcel' | 'postal' | 'express' | 'road_freight' | 'air_cargo' | 'ocean_container';

export type GetApiCarriersArgs = {query?: string | undefined, transport_mode?: TransportMode | undefined, limit?: number | undefined};

export type GetApiCarriersOptions = {baseUrl: string, bearerAuth?: string | undefined, fetch?: typeof fetch | undefined};

export const transportMode = z.enum(["parcel", "postal", "express", "road_freight", "air_cargo", "ocean_container"]);

export const deliveryEstimateCarrierSearchResponse = z.object({query: z.string(), transport_mode: transportMode.nullable().optional(), carriers: z.array(z.object({slug: z.string(), name: z.string(), aliases: z.array(z.string()), transport_modes: z.array(transportMode)})), total_matches: z.number().int().gte(0), has_more: z.boolean()});

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
};

/**
 * Find canonical carrier slugs (beta)
 * 
 * GET /carriers
 */
export const getApiCarriers = async (args: GetApiCarriersArgs, options: GetApiCarriersOptions) => {
const {baseUrl, fetch: fetchFn = fetch, bearerAuth} = options ?? {}

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

if (args.query != null) query.append("query", String(args.query))
if (args.transport_mode != null) query.append("transport_mode", String(args.transport_mode))
if (args.limit != null) query.append("limit", String(args.limit))
if (bearerAuth !== undefined) headers.set('authorization', `Bearer ${bearerAuth}`)

const url = `${baseUrl.replace(/\/+$/, '')}/carriers${query.size > 0 ? `?${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(deliveryEstimateCarrierSearchResponse, await res.json())
};