import { createHmac } from "node:crypto";
import type { GenerationJob, WebhookLastStatus } from "@/lib/types";

export type JobWebhookPayload = {
  jobId: string;
  status: GenerationJob["status"];
  capability: GenerationJob["capability"];
  outputAssetIds: string[];
  error?: GenerationJob["error"];
  updatedAt: string;
};

const MAX_WEBHOOK_ATTEMPTS = 3;

export function buildJobWebhookPayload(job: GenerationJob): JobWebhookPayload {
  return {
    jobId: job.id,
    status: job.status,
    capability: job.capability,
    outputAssetIds: job.outputAssetIds,
    error: job.error,
    updatedAt: job.updatedAt
  };
}

export function signWebhookBody(body: string, secret = process.env.ZHINIAN_WEBHOOK_SECRET): string | undefined {
  if (!secret?.trim()) return undefined;
  return `sha256=${createHmac("sha256", secret.trim()).update(body).digest("hex")}`;
}

export async function deliverJobWebhook(job: GenerationJob): Promise<{
  attempts: number;
  lastStatus?: WebhookLastStatus;
}> {
  if (!job.webhookUrl) return { attempts: job.webhookAttempts || 0 };
  let attempts = job.webhookAttempts || 0;
  let lastStatus: WebhookLastStatus | undefined = job.webhookLastStatus;
  const payload = buildJobWebhookPayload(job);
  const body = JSON.stringify(payload);
  const signature = signWebhookBody(body);

  while (attempts < MAX_WEBHOOK_ATTEMPTS) {
    attempts += 1;
    const attemptedAt = new Date().toISOString();
    try {
      const response = await fetch(job.webhookUrl, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          "User-Agent": "zhinian-aigc-webhook/1.0",
          ...(signature ? { "X-Zhinian-Signature": signature } : {})
        },
        body
      });
      lastStatus = {
        ok: response.ok,
        status: response.status,
        attemptedAt
      };
      if (response.ok) break;
    } catch (error) {
      lastStatus = {
        ok: false,
        error: error instanceof Error ? error.message : String(error),
        attemptedAt
      };
    }
  }

  return { attempts, lastStatus };
}