import { randomUUID } from "node:crypto";

import cors from "cors";
import express from "express";

import { ChatSessionBridge } from "./chat/sessionBridge.js";
import { config } from "./config.js";
import { logger } from "./logger.js";
import { buildChatRouter } from "./routes/chat.js";
import { opencodeRuntime } from "./runtime/opencode.js";
import { SessionRegistry } from "./session/registry.js";
import { dynamicHttpExecutor } from "./tools/dynamicHttpExecutor.js";

const app = express();
const registry = new SessionRegistry(config.SESSION_TTL_SECONDS);
const sessionBridge = new ChatSessionBridge(registry, opencodeRuntime);
const internalToken = config.AGENT_INTERNAL_TOKEN ?? randomUUID();

// 这个 token 只用于 .opencode/tools 回调本服务，避免把 internal endpoint 暴露成无鉴权入口。
process.env.TJWATER_AGENT_INTERNAL_TOKEN = internalToken;

app.use(cors());
app.use(express.json({ limit: "1mb" }));

app.get("/health", async (_req, res) => {
  try {
    const runtime = await opencodeRuntime.health();
    res.json({
      ok: true,
      runtime,
      sessions: sessionBridge.count(),
    });
  } catch (error) {
    const detail = error instanceof Error ? error.message : String(error);
    res.status(503).json({
      ok: false,
      message: "opencode runtime unavailable",
      detail,
      sessions: sessionBridge.count(),
    });
  }
});

app.post("/internal/tools/dynamic-http-call", async (req, res) => {
  if (req.header("x-agent-internal-token") !== internalToken) {
    res.status(403).json({ message: "forbidden" });
    return;
  }

  const sessionId = typeof req.body?.sessionId === "string" ? req.body.sessionId : "";
  const context = sessionBridge.getSessionContext(sessionId);
  if (!context) {
    res.status(404).json({
      message: "session context not found",
      detail: sessionId,
    });
    return;
  }

  try {
    // opencode 工具运行在 .opencode 侧，这里负责把工具调用重新绑定到当前用户/项目上下文。
    const result = await dynamicHttpExecutor.execute(
      {
        path: req.body?.path,
        method: req.body?.method,
        arguments: req.body?.arguments,
      },
      context,
    );
    res.json(result);
  } catch (error) {
    const detail = error instanceof Error ? error.message : String(error);
    res.status(400).json({
      message: "dynamic http execution failed",
      detail,
    });
  }
});

app.use("/api/v1/copilot/chat", buildChatRouter(sessionBridge, opencodeRuntime));

const server = app.listen(config.PORT, config.HOST, () => {
  logger.info(
    { host: config.HOST, port: config.PORT },
    "TJWaterAgent listening",
  );
});

const shutdown = async () => {
  logger.info("shutting down TJWaterAgent");
  server.close();
  // 同步关闭 embedded opencode server，避免本服务退出后留下孤儿进程。
  await opencodeRuntime.dispose();
};

process.on("SIGINT", () => {
  void shutdown();
});

process.on("SIGTERM", () => {
  void shutdown();
});