import {z} from 'zod'

export type GetApiAskArgs = {query: string, query_id?: string | undefined, streaming?: boolean | undefined};

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

export const nlwebAnswerMeta = z.object({response_type: z.literal("answer"), version: z.literal("0.55"), streaming: z.boolean().optional()});

export const nlwebResult = z.object({url: z.string(), name: z.string(), site: z.string(), score: z.number(), description: z.string(), schema_object: z.record(z.string(), z.unknown())});

export const nlwebAnswer = z.object({query_id: z.string(), _meta: nlwebAnswerMeta, results: z.array(nlwebResult)});

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
};

/**
 * Search c15t documentation
 * 
 * GET /ask
 */
export const getApiAsk = async (args: GetApiAskArgs, options?: GetApiAskOptions) => {
const {baseUrl = "https://c15t.com", fetch: fetchFn = fetch} = options ?? {}

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

if (args.query != null) query.append("query", String(args.query))
if (args.query_id != null) query.append("query_id", String(args.query_id))
if (args.streaming != null) query.append("streaming", String(args.streaming))

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