import { z } from 'zod';

const errorSchema = z.object({ code: z.string().optional(), error: z.string().optional() });

export class AgentApiError extends Error {
  constructor(
    public readonly status: number,
    public readonly code?: string
  ) {
    super(`Agent request failed (HTTP ${status}).${code ? ` Code: ${code}.` : ''}`);
  }
}

export async function agentRequest(url: string, init?: RequestInit): Promise<Response> {
  try {
    const timeout = AbortSignal.timeout(30_000);
    const signal = init?.signal ? AbortSignal.any([init.signal, timeout]) : timeout;
    return await fetch(url, { ...init, redirect: 'error', signal });
  } catch {
    throw new Error('Could not reach the agent service. Retry the same command.');
  }
}

export async function agentResponse<T>(response: Response, schema: z.ZodType<T>): Promise<T> {
  const body: unknown = await response.json().catch(() => null);
  if (!response.ok) {
    const error = errorSchema.safeParse(body);
    const code = error.success ? (error.data.code ?? error.data.error) : undefined;
    throw new AgentApiError(response.status, code?.match(/^[a-z_]{1,80}$/)?.[0]);
  }
  const parsed = schema.safeParse(body);
  if (!parsed.success) throw new Error('The agent service returned an unexpected response.');
  return parsed.data;
}