import {z} from 'zod'

export type MetricsRequestWithOptions = {endTime: string, mpl?: string | undefined, startTime: string};

export type CreateApiQueryMplArgs = {format?: ('metrics-v1' | 'metrics-v2' | 'metrics-v3' | 'metrics-v4') | undefined, body: MetricsRequestWithOptions};

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

export const metricsResult = z.object({});

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
};

/**
 * Runs an MPL query against metrics datasets in this edge deployment. The response format follows the `format` parameter or the `Accept` header and defaults to `metrics-v2`. Returns `429` when a query cost limit is exhausted.
 * 
 * POST /query/_mpl
 */
export const createApiQueryMpl = async (args: CreateApiQueryMplArgs, options: CreateApiQueryMplOptions) => {
const {baseUrl, fetch: fetchFn = fetch, Auth} = options ?? {}

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

if (args.format != null) query.append("format", String(args.format))
if (Auth !== undefined) headers.set('authorization', `Bearer ${Auth}`)

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