import {z} from 'zod'

export type GetApiTripsArgs = {from_lat: number, from_lon: number, to_lat: number, to_lon: number, alerts?: 1 | undefined};

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

export const tripLeg = z.object({line: z.string(), direction: z.string(), mode: z.enum(["subway", "suburban", "tram", "bus", "ferry", "regional", "express"]).optional(), from: z.string(), to: z.string(), departure: z.number().int(), arrival: z.number().int(), departureDelay: z.number().int(), arrivalDelay: z.number().int(), departurePlatform: z.string().optional(), cancelled: z.boolean(), stops: z.number().int(), stopNames: z.array(z.string()).optional(), sameVehicle: z.boolean().optional(), alerts: z.array(z.string()).optional()});

export const trip = z.object({legs: z.array(tripLeg), departure: z.number().int(), arrival: z.number().int(), duration: z.number().int(), changes: z.number().int()});

export const disruption = z.object({id: z.string(), severity: z.enum(["info", "warning", "severe"]), effect: z.enum(["cancellation", "delay", "detour", "stop_moved", "replacement_service", "accessibility", "other"]).optional(), title: z.string(), description: z.string().optional(), lines: z.array(z.string()).optional(), stopNames: z.array(z.string()).optional(), mode: z.enum(["subway", "suburban", "tram", "bus", "ferry", "regional", "express"]).optional(), validFrom: z.number().int().optional(), validTo: z.number().int().optional(), url: z.string().optional(), source: z.string(), attribution: z.string().optional()});

export const tripResponse = z.object({region: z.string(), trips: z.array(trip), attribution: z.string().optional(), disruptions: z.array(disruption).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
};

/**
 * Plan a trip
 * 
 * GET /trips
 * 
 * Also accepts auth: ApiKeyQuery
 */
export const getApiTrips = async (args: GetApiTripsArgs, options?: GetApiTripsOptions) => {
const {baseUrl = "https://api.abfahrt.now", fetch: fetchFn = fetch, ApiKeyHeader} = options ?? {}

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

if (args.from_lat != null) query.append("from_lat", String(args.from_lat))
if (args.from_lon != null) query.append("from_lon", String(args.from_lon))
if (args.to_lat != null) query.append("to_lat", String(args.to_lat))
if (args.to_lon != null) query.append("to_lon", String(args.to_lon))
if (args.alerts != null) query.append("alerts", String(args.alerts))
if (ApiKeyHeader !== undefined) headers.set("x-api-key", ApiKeyHeader)

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