import {z} from 'zod'

export type DCRRequest = {client_name?: string | undefined, client_uri?: (string | null) | undefined, logo_uri?: (string | null) | undefined, redirect_uris?: Array<string> | undefined, grant_types?: Array<string> | undefined, response_types?: Array<string> | undefined, token_endpoint_auth_method?: string | undefined, scope?: string | undefined, application_type?: string | undefined, require_pushed_authorization_requests: unknown};

export type CreateApiOauthRegisterArgs = {'user-agent'?: (string | null) | undefined, body: DCRRequest};

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

export const dCRResponse = z.object({client_id: z.string(), client_id_issued_at: z.number().int(), client_name: z.string(), client_uri: z.string().nullable().optional(), logo_uri: z.string().nullable().optional(), redirect_uris: z.array(z.string()), grant_types: z.array(z.string()), response_types: z.array(z.string()), token_endpoint_auth_method: z.string(), scope: z.string(), application_type: z.string(), require_pushed_authorization_requests: z.boolean().optional(), registration_client_uri: z.string(), registration_access_token: z.string()});

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
};

/**
 * Dynamic Client Registration (RFC 7591)
 * 
 * POST /oauth/register
 */
export const createApiOauthRegister = async (args: CreateApiOauthRegisterArgs, options: CreateApiOauthRegisterOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

if (args['user-agent'] != null) headers.set("user-agent", String(args['user-agent']))

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

const res = await fetchFn(url, {method: "POST", headers, body: JSON.stringify(args.body)})

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

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