import {z} from 'zod'

export type GetApiIndexUuidRunStateArgs = {uuid: string};

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

export const isoTS = z.string();

export const runStateStatus = z.enum(["PENDING_CREATION", "SUCCEEDED", "FAILED", "RUNNING"]);

export const runState = z.object({calculation_start_ts: isoTS.optional(), error: z.string().optional(), status: runStateStatus});

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
};

/**
 * get the latest run state of the index. May be enhanced in the future to support quering for a given eff_ts (e.g., historically).
 * 
 * GET /index/{uuid}/run_state
 */
export const getApiIndexUuidRunState = async (args: GetApiIndexUuidRunStateArgs, options?: GetApiIndexUuidRunStateOptions) => {
const {baseUrl = "https://api.merqube.com", fetch: fetchFn = fetch} = options ?? {}

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

const url = `${baseUrl.replace(/\/+$/, '')}/index/${encodeURIComponent(String(args.uuid))}/run_state${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(runState, await res.json())
};