import {z} from 'zod'

export type GetApiHapiCatalogArgs = {depth?: (string | null) | undefined, resolve_references?: (string | null) | undefined};

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

export const hAPICatalogDataset = z.object({id: z.string(), title: z.string(), info: z.record(z.string(), z.unknown()).nullable().optional()});

export const hAPIStatus = z.object({code: z.number().int(), message: z.string()});

export const hAPICatalog = z.object({HAPI: z.string(), catalog: z.array(hAPICatalogDataset), status: hAPIStatus});

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
};

/**
 * HAPI catalog of available datasets
 * 
 * GET /hapi/catalog
 */
export const getApiHapiCatalog = async (args: GetApiHapiCatalogArgs, options: GetApiHapiCatalogOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

if (args.depth != null) query.append("depth", String(args.depth))
if (args.resolve_references != null) query.append("resolve_references", String(args.resolve_references))

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