import {z} from 'zod'

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

export const metricsResponse = z.object({agent_metrics: z.object({uptime_seconds: z.number().optional(), total_requests: z.number().int().optional(), success_requests: z.number().int().optional(), failed_requests: z.number().int().optional(), blocked_requests: z.number().int().optional(), success_rate: z.number().optional(), rps: z.number().optional(), error_rate_per_sec: z.number().optional(), p50_ms: z.number().optional(), p95_ms: z.number().optional(), p99_ms: z.number().optional(), avg_latency_ms: z.number().optional(), auth_p99_ms: z.number().optional(), static_policy_eval_p99_ms: z.number().optional(), network_p99_ms: z.number().optional()}).optional(), health: z.object({status: z.enum(["healthy", "degraded", "unhealthy"]).optional(), healthy: z.boolean().optional(), consecutive_errors: z.number().int().optional(), up: z.number().int().optional()}).optional(), request_types: z.record(z.string(), z.object({total_requests: z.number().int().optional(), success_requests: z.number().int().optional(), p99_ms: z.number().optional()})).optional(), connectors: z.record(z.string(), z.object({total_requests: z.number().int().optional(), success_rate: z.number().optional(), p99_ms: z.number().optional()})).optional(), timestamp: 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
};

/**
 * Get performance metrics
 * 
 * GET /metrics
 */
export const getApiMetrics = async (options?: GetApiMetricsOptions) => {
const {baseUrl = "https://agent.getaxonflow.com", fetch: fetchFn = fetch} = options ?? {}

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

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