import type { ExtensionAPI, ExtensionContext } from "@earendil-works/pi-coding-agent";
import { spawn, type ChildProcess } from "node:child_process";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";

const __dirname = dirname(fileURLToPath(import.meta.url));
const SERVER_ENTRY = join(__dirname, "..", "server", "index.js");

function openBrowser(url: string) {
  const platform = process.platform;
  try {
    if (platform === "darwin") {
      spawn("open", [url], { detached: true, stdio: "ignore" }).unref();
    } else if (platform === "win32") {
      spawn("cmd", ["/c", "start", "", url], { detached: true, stdio: "ignore" }).unref();
    } else {
      spawn("xdg-open", [url], { detached: true, stdio: "ignore" }).unref();
    }
  } catch {
    // 打开浏览器失败不影响服务本身，用户可手动访问 url
  }
}

export default function (pi: ExtensionAPI) {
  let proc: ChildProcess | null = null;
  let url = "";

  function stop(ctx: ExtensionContext) {
    if (!proc) return;
    proc.kill();
    proc = null;
    ctx.ui.notify("Pi Web Console 已停止", "info");
  }

  pi.registerCommand("web-console", {
    description: "启动/停止 Pi Web Console（本会话的浏览器 UI）。用法：/web-console [port|stop]",
    handler: async (args, ctx) => {
      const arg = args.trim();

      if (arg === "stop") {
        stop(ctx);
        return;
      }

      if (proc) {
        ctx.ui.notify(`Pi Web Console 已在运行：${url}`, "info");
        openBrowser(url);
        return;
      }

      const port = /^\d+$/.test(arg) ? arg : process.env.PI_WEB_CONSOLE_PORT || "4120";
      const host = process.env.PI_WEB_CONSOLE_HOST || "127.0.0.1";

      proc = spawn(process.execPath, [SERVER_ENTRY], {
        cwd: ctx.cwd,
        env: {
          ...process.env,
          HOST: host,
          PORT: port,
          DEFAULT_CWD: ctx.cwd,
        },
        stdio: "ignore",
      });

      proc.on("exit", () => {
        proc = null;
      });

      url = `http://${host}:${port}`;
      ctx.ui.notify(`Pi Web Console 启动中：${url}`, "info");
      openBrowser(url);
    },
  });

  pi.on("session_shutdown", async (_event, ctx) => {
    stop(ctx);
  });
}