import {z} from 'zod'

export type GetApiV1QueryArgs = {q: string, pretty?: boolean | undefined, explain?: string | undefined, metrics?: boolean | undefined};

export type GetApiV1QueryOptions = {baseUrl: string, fetch?: typeof fetch | undefined};

export const getApiV1QueryResponse = z.object({result: z.array(z.object({id: z.string().min(1).optional(), raw: z.string().min(1).optional(), ast: z.object({package: z.object({path: z.array(z.object({type: z.enum(["import", "package"]).optional(), value: z.string().optional()})).optional()}).optional(), rules: z.array(z.object({head: z.object({name: z.string().optional(), key: z.object({type: z.string().optional(), value: z.string().optional()}).optional()}).optional(), body: z.array(z.object({index: z.number().optional(), terms: z.array(z.object({type: z.string().optional(), value: z.array(z.object({type: z.string().optional(), value: z.string().optional()})).optional()})).optional()})).optional()})).optional()}).optional()})).optional(), metrics: z.object({timer_rego_input_parse_ns: z.number().optional(), timer_rego_query_parse_ns: z.number().optional(), timer_rego_query_compile_ns: z.number().optional(), timer_rego_query_eval_ns: z.number().optional(), timer_rego_module_parse_ns: z.number().optional(), timer_rego_module_compile_ns: z.number().optional(), timer_server_handler_ns: z.number().optional(), timer_server_read_bytes_ns: z.number().optional(), counter_server_query_cache_hit: z.number().optional(), timer_query_compile_stage_build_comprehension_index_ns: z.number().optional(), timer_query_compile_stage_check_safety_ns: z.number().optional(), timer_query_compile_stage_check_types_ns: z.number().optional(), timer_query_compile_stage_check_undefined_funcs_ns: z.number().optional(), timer_query_compile_stage_check_unsafe_builtins_ns: z.number().optional(), timer_query_compile_stage_resolve_refs_ns: z.number().optional(), timer_query_compile_stage_rewrite_comprehension_terms_ns: z.number().optional(), timer_query_compile_stage_rewrite_dynamic_terms_ns: z.number().optional(), timer_query_compile_stage_rewrite_expr_terms_ns: z.number().optional(), timer_query_compile_stage_rewrite_local_vars_ns: z.number().optional(), timer_query_compile_stage_rewrite_to_capture_value_ns: z.number().optional(), timer_query_compile_stage_rewrite_with_values_ns: z.number().optional()}).optional(), explanation: z.array(z.object({op: z.enum(["enter", "exit", "eval", "fail", "redo"]).optional(), query_id: z.number().gte(0).optional(), parent_id: z.number().gte(0).optional(), type: z.enum(["expr", "rule", "body"]).optional(), node: z.object({index: z.number().optional(), terms: z.array(z.object({type: z.string().optional(), value: z.string().optional()})).optional()}).optional(), locals: z.array(z.object({key: z.object({type: z.string().optional(), value: z.string().optional()}).optional(), value: z.object({type: z.string().optional(), value: z.string().optional()}).optional()})).optional()})).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
};

/**
 * Execute an ad-hoc query (simple)
 * 
 * GET /v1/query
 */
export const getApiV1Query = async (args: GetApiV1QueryArgs, options: GetApiV1QueryOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

if (args.q != null) query.append("q", String(args.q))
if (args.pretty != null) query.append("pretty", String(args.pretty))
if (args.explain != null) query.append("explain", String(args.explain))
if (args.metrics != null) query.append("metrics", String(args.metrics))

const url = `${baseUrl.replace(/\/+$/, '')}/v1/query${query.size > 0 ? `?${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(getApiV1QueryResponse, await res.json())
};