import {z} from 'zod'

export type VectorEncoding = 'float' | 'base64';

export type IncludeAttributes = boolean | Array<string>;

export type DistanceMetric = 'cosine_distance' | 'euclidean_squared';

export type Limit = {total: number, per?: {attributes: Array<string>, limit: number} | undefined};

export type CreateApiV2NamespacesNamespaceExplainQueryArgs = {namespace: string, body: {vector_encoding?: VectorEncoding | undefined, consistency?: ({level: 'strong'} | {level: 'eventual', max_staleness_seconds?: number | undefined}) | undefined, rank_by: unknown, top_k?: number | undefined, offset?: number | undefined, filters: unknown, include_attributes?: IncludeAttributes | undefined, exclude_attributes?: Array<string> | undefined, aggregate_by?: {[key: string]: unknown} | undefined, group_by?: Array<unknown> | undefined, compute_attributes?: {[key: string]: unknown} | undefined, distance_metric?: DistanceMetric | undefined, limit?: (number | Limit) | undefined}};

export type CreateApiV2NamespacesNamespaceExplainQueryOptions = {baseUrl?: string | undefined, bearerAuth?: string | undefined, fetch?: typeof fetch | undefined};

export const createApiV2NamespacesNamespaceExplainQueryResponse = z.object({plan_text: z.string().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
};

/**
 * Explain a query plan.
 * 
 * POST /v2/namespaces/{namespace}/explain_query
 */
export const createApiV2NamespacesNamespaceExplainQuery = async (args: CreateApiV2NamespacesNamespaceExplainQueryArgs, options?: CreateApiV2NamespacesNamespaceExplainQueryOptions) => {
const {baseUrl = "https://undefined.turbopuffer.com", fetch: fetchFn = fetch, bearerAuth} = options ?? {}

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

if (bearerAuth !== undefined) headers.set('authorization', `Bearer ${bearerAuth}`)

const url = `${baseUrl.replace(/\/+$/, '')}/v2/namespaces/${encodeURIComponent(String(args.namespace))}/explain_query${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(createApiV2NamespacesNamespaceExplainQueryResponse, await res.json())
};