import {z} from 'zod'

export type GetApiOnpremV1HostedModelsArgs = {upstream?: ('vertex' | 'bedrock' | null) | undefined, 'X-Definite-License'?: (string | null) | undefined};

export type GetApiOnpremV1HostedModelsOptions = {baseUrl: string, fetch?: typeof fetch | undefined};

export const hostedLlmModelRow = z.object({model_id: z.string(), display_name: z.string().nullable().optional()});

export const hostedModelsResponse = z.object({models: z.array(hostedLlmModelRow).optional()});

export const responseMeta = z.object({requestId: z.string().optional(), timestamp: z.string().optional(), durationMs: z.number().int().nullable().optional()});

export const successResponseHostedModelsResponse = z.object({success: z.literal(true), data: hostedModelsResponse, meta: responseMeta.optional()});

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
};

/**
 * Fetch the fleet-wide whitelisted LLM model list
 * 
 * GET /onprem/v1/hosted-models
 */
export const getApiOnpremV1HostedModels = async (args: GetApiOnpremV1HostedModelsArgs, options: GetApiOnpremV1HostedModelsOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

if (args.upstream != null) query.append("upstream", String(args.upstream))
if (args['X-Definite-License'] != null) headers.set("X-Definite-License", String(args['X-Definite-License']))

const url = `${baseUrl.replace(/\/+$/, '')}/onprem/v1/hosted-models${query.size > 0 ? `?${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(successResponseHostedModelsResponse, await res.json())
};