main.js

const { app, BrowserWindow } = require("electron");
const { spawn } = require("child_process");
const path = require("path");
const fs = require("fs");

let win = null;
let py = null;
let quitting = false;

function safeSend(channel, payload) {
  if (!win) return;
  const wc = win.webContents;
  if (win.isDestroyed()) return;
  if (!wc || wc.isDestroyed()) return;
  wc.send(channel, payload);
}

function cleanupPython() {
  if (!py) return;
  try {
    py.stdout?.removeAllListeners();
    py.stderr?.removeAllListeners();
    py.removeAllListeners();
    py.stdout?.destroy();
    py.stderr?.destroy();
    if (!py.killed) py.kill("SIGTERM");
  } catch {}
  py = null;
}

function createWindow() {
  win = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: { preload: path.join(__dirname, "preload.js") },
  });
  win.loadFile("index.html");

  const venvPython = path.join(__dirname, "venv", "bin", "python");
  const pythonCmd = fs.existsSync(venvPython)
    ? venvPython
    : process.platform === "win32"
      ? path.join(__dirname, "venv", "Scripts", "python.exe")
      : "python3";

  py = spawn(pythonCmd, [path.join(__dirname, "main.py")], {
    cwd: __dirname,
    env: { ...process.env },
  });

  py.stdout.on("data", (data) => {
    safeSend("py:stdout", data.toString());
  });
  py.stderr.on("data", (data) => {
    safeSend("py:stderr", data.toString());
  });
  py.on("close", (code) => {
    safeSend("py:exit", code);
  });

  win.on("closed", () => {
    cleanupPython();
    win = null;
  });

  win.webContents.on("destroyed", () => {
    cleanupPython();
  });
}

app.on("before-quit", () => {
  quitting = true;
  cleanupPython();
});

app.whenReady().then(createWindow);

app.on("window-all-closed", () => {
  cleanupPython();
  if (process.platform !== "darwin") app.quit();
});

app.on("activate", () => {
  if (BrowserWindow.getAllWindows().length === 0 && !quitting) createWindow();
});