import {z} from 'zod'

export type GetApiTravelPredictionsTripPurposeArgs = {originLocationCode: string, destinationLocationCode: string, departureDate: string, returnDate: string, searchDate?: string | undefined};

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

export const predictionResultType = z.enum(["BUSINESS", "LEISURE"]);

export const purposePrediction = z.object({type: z.string().optional(), subType: z.string().optional(), id: z.string().optional(), result: predictionResultType.optional(), probability: z.string().optional()});

export const links = z.object({self: z.string().optional(), related: z.string().optional(), type: z.string().optional()});

export const defaults = z.object({searchDate: z.string().optional()});

export const meta = z.object({links: links.optional(), defaults: defaults.optional()});

export const prediction = z.object({data: purposePrediction.optional(), meta: meta.optional()});

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
};

/**
 * Returns the forecast purpose of a trip
 * 
 * GET /travel/predictions/trip-purpose
 */
export const getApiTravelPredictionsTripPurpose = async (args: GetApiTravelPredictionsTripPurposeArgs, options?: GetApiTravelPredictionsTripPurposeOptions) => {
const {baseUrl = "https://test.api.amadeus.com/v1", fetch: fetchFn = fetch} = options ?? {}

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

if (args.originLocationCode != null) query.append("originLocationCode", String(args.originLocationCode))
if (args.destinationLocationCode != null) query.append("destinationLocationCode", String(args.destinationLocationCode))
if (args.departureDate != null) query.append("departureDate", String(args.departureDate))
if (args.returnDate != null) query.append("returnDate", String(args.returnDate))
if (args.searchDate != null) query.append("searchDate", String(args.searchDate))

const url = `${baseUrl.replace(/\/+$/, '')}/travel/predictions/trip-purpose${query.size > 0 ? `?${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(prediction, await res.json())
};