// ═══════════════════════════════════════
// 铸渊开发Agent · 任务接收端点
// 接收铸渊的结构化规划清单 → 暂存 → 通知
// ═══════════════════════════════════════

const fs = require("fs");
const path = require("path");

const PLANS_DIR = path.join(__dirname, "..", "plans");
const QUEUE_FILE = path.join(__dirname, "..", "plans", "queue.json");

// 确保目录存在
if (!fs.existsSync(PLANS_DIR)) fs.mkdirSync(PLANS_DIR, { recursive: true });
if (!fs.existsSync(QUEUE_FILE)) fs.writeFileSync(QUEUE_FILE, "[]", "utf-8");

/**
 * 验证请求来源
 */
function verifySource(req) {
  const auth = req.headers["authorization"] || "";
  const expectedKey = process.env.ZY_GTW_KEY || "";
  if (!expectedKey) {
    console.warn("[TaskReceiver] ZY_GTW_KEY 未配置，跳过验证");
    return true;
  }
  return auth === "Bearer " + expectedKey;
}

/**
 * 验证规划清单结构
 */
function validatePlan(plan) {
  if (!plan.plan_id) return { ok: false, error: "缺少 plan_id" };
  if (!plan.title) return { ok: false, error: "缺少 title" };
  if (!plan.tasks || !Array.isArray(plan.tasks)) return { ok: false, error: "缺少 tasks 数组" };
  if (plan.tasks.length === 0) return { ok: false, error: "tasks 不能为空" };
  
  for (let i = 0; i < plan.tasks.length; i++) {
    const t = plan.tasks[i];
    if (!t.id) return { ok: false, error: "task[" + i + "] 缺少 id" };
    if (!t.action) return { ok: false, error: "task[" + i + "] 缺少 action" };
  }
  
  return { ok: true };
}

/**
 * 接收并暂存规划清单
 */
function receivePlan(plan) {
  // 写入独立文件
  const planFile = path.join(PLANS_DIR, plan.plan_id + ".json");
  plan._received_at = new Date().toISOString();
  plan._status = "received";
  fs.writeFileSync(planFile, JSON.stringify(plan, null, 2), "utf-8");
  
  // 推入队列
  const queue = JSON.parse(fs.readFileSync(QUEUE_FILE, "utf-8"));
  queue.push({
    plan_id: plan.plan_id,
    title: plan.title,
    task_count: plan.tasks.length,
    received_at: plan._received_at,
    status: "received"
  });
  fs.writeFileSync(QUEUE_FILE, JSON.stringify(queue, null, 2), "utf-8");
  
  console.log("[TaskReceiver] 收到规划: " + plan.plan_id + " · " + plan.tasks.length + "个任务");
  
  return {
    received: true,
    plan_id: plan.plan_id,
    task_count: plan.tasks.length,
    stored_at: planFile
  };
}

/**
 * Express 路由处理器
 */
function handleTask(req, res) {
  try {
    if (!verifySource(req)) {
      return res.status(403).json({ error: "未授权 — 来源未通过 Gatekeeper 验证" });
    }
    
    const plan = req.body;
    const validation = validatePlan(plan);
    if (!validation.ok) {
      return res.status(400).json({ error: validation.error });
    }
    
    const result = receivePlan(plan);
    return res.status(201).json(result);
    
  } catch (err) {
    console.error("[TaskReceiver] 错误:", err.message);
    return res.status(500).json({ error: "内部错误: " + err.message });
  }
}

module.exports = { handleTask };