import {z} from 'zod'

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

export const getApiApiWorkloadResponse = z.object({timestamp: z.number().int().optional(), workspace_id: z.number().int().optional(), capacity: z.object({active_tasks: z.number().int().optional(), tasks_last_5m: z.number().int().optional(), errors_last_5m: z.number().int().optional(), error_rate_5m: z.number().gte(0).lte(1).optional(), completions_last_hour: z.number().int().optional(), avg_completion_rate_per_hour: z.number().optional()}).optional(), queue: z.object({total_pending: z.number().int().optional(), by_status: z.record(z.string(), z.number().int()).optional(), by_priority: z.record(z.string(), z.number().int()).optional(), oldest_pending_age_seconds: z.number().int().nullable().optional(), estimated_wait_seconds: z.number().int().nullable().optional(), estimated_wait_confidence: z.enum(["calculated", "unknown"]).optional()}).optional(), agents: z.object({total: z.number().int().optional(), online: z.number().int().optional(), busy: z.number().int().optional(), idle: z.number().int().optional(), offline: z.number().int().optional(), busy_ratio: z.number().gte(0).lte(1).optional(), load_distribution: z.array(z.object({agent: z.string().optional(), assigned: z.number().int().optional(), in_progress: z.number().int().optional()})).optional()}).optional(), recommendation: z.object({action: z.enum(["normal", "throttle", "shed", "pause"]).optional(), reason: z.string().optional(), details: z.array(z.string()).optional(), submit_ok: z.boolean().optional(), suggested_delay_ms: z.number().int().optional()}).optional(), thresholds: z.object({}).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 real-time workload recommendation
 * 
 * GET /api/workload
 * 
 * Also accepts auth: apiKey
 */
export const getApiApiWorkload = async (options: GetApiApiWorkloadOptions) => {
const {baseUrl, fetch: fetchFn = fetch, sessionCookie} = options ?? {}

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

if (sessionCookie !== undefined) cookies.push("__Host-mc-session=" + encodeURIComponent(sessionCookie))

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