/* Open Battery Information — Electron main process.
Loads the OBI-1 page and provides native serial access through the
`serialport` package (no browser Web Serial needed). The renderer talks
to the serial port over IPC via the preload bridge and a small
navigator.serial shim. Everything stays local; no telemetry. */
const { app, BrowserWindow, Menu, ipcMain, shell } = require('electron');
const path = require('path');
process.on('uncaughtException', (err) => {
console.error('[main] uncaughtException:', err);
});
process.on('unhandledRejection', (reason) => {
console.error('[main] unhandledRejection:', reason);
});
let SerialPort = null;
try {
({ SerialPort } = require('serialport'));
console.log('[main] serialport loaded');
} catch (err) {
console.error('[main] serialport failed to load:', err.message);
}
const SITE_DIR = path.join(__dirname, 'site');
const openPorts = new Map(); // port path -> { port, sender }
let pickerPromise = null;
/* ---------- serialport helpers ---------- */
function toPortInfo(p) {
return {
path: p.path,
vendorId: p.vendorId ? parseInt(p.vendorId, 16) : 0,
productId: p.productId ? parseInt(p.productId, 16) : 0,
manufacturer: p.manufacturer || '',
serialNumber: p.serialNumber || '',
};
}
function openPort(info, baudRate) {
return new Promise((resolve, reject) => {
const port = new SerialPort(
{ path: info.path, baudRate: baudRate || 9600 },
(err) => (err ? reject(err) : resolve(port))
);
port.on('error', () => {});
});
}
/* ---------- IPC: serial ---------- */
ipcMain.handle('serial:list', async () => {
const list = await SerialPort.list();
return list.map(toPortInfo);
});
ipcMain.handle('serial:requestPort', async (event) => {
const win = BrowserWindow.fromWebContents(event.sender);
const info = await showPortPicker(win);
if (!info) throw new Error('NotFoundError: No port selected');
return info;
});
ipcMain.handle('serial:open', async (event, info, baudRate) => {
const existing = openPorts.get(info.path);
if (existing && existing.port.isOpen) return { ok: true };
const port = await openPort(info, baudRate);
port.on('data', (buf) => {
const entry = openPorts.get(info.path);
if (entry && entry.sender && !entry.sender.isDestroyed()) {
entry.sender.send('serial:data', info.path, buf);
}
});
port.on('close', () => openPorts.delete(info.path));
openPorts.set(info.path, { port, sender: event.sender });
return { ok: true };
});
ipcMain.handle('serial:setSignals', async (_event, info, dtr) => {
const entry = openPorts.get(info.path);
if (!entry) throw new Error('Serial port is not open');
await new Promise((resolve, reject) =>
entry.port.set({ dtr: !!dtr }, (err) => (err ? reject(err) : resolve()))
);
return { ok: true };
});
ipcMain.handle('serial:write', async (_event, info, data) => {
const entry = openPorts.get(info.path);
if (!entry) throw new Error('Serial port is not open');
await new Promise((resolve, reject) =>
entry.port.write(Buffer.from(data), (err) => (err ? reject(err) : resolve()))
);
return { ok: true };
});
ipcMain.handle('serial:close', async (_event, info) => {
const entry = openPorts.get(info.path);
if (!entry) return { ok: true };
openPorts.delete(info.path);
await new Promise((resolve) => entry.port.close(() => resolve()));
return { ok: true };
});
/* ---------- serial port picker ---------- */
const escapeHtml = (s) =>
String(s).replace(/[&<>"']/g, (c) =>
({ '&': '&', '<': '<', '>': '>', '"': '"', "'": ''' }[c])
);
const PICKER_HTML = `
Select a serial port
Choose the Arduino running the OBI firmware.
`;
function showPortPicker(parent) {
if (pickerPromise) return pickerPromise;
pickerPromise = (async () => {
let list = [];
try {
list = await SerialPort.list();
} catch (e) {
list = [];
}
if (!list.length) return null;
return await new Promise((resolve) => {
const picker = new BrowserWindow({
parent,
modal: true,
width: 540,
height: 440,
resizable: false,
autoHideMenuBar: true,
title: 'Select a serial port',
backgroundColor: '#1e1f22',
webPreferences: {
preload: path.join(__dirname, 'preload-picker.js'),
contextIsolation: true,
nodeIntegration: false,
},
});
const rows = list
.map(
(p) =>
''
)
.join('');
ipcMain.once('picker:select', (_e, pickedPath) => {
const info = list.find((p) => p.path === pickedPath);
if (picker && !picker.isDestroyed()) picker.close();
resolve(info ? toPortInfo(info) : null);
});
ipcMain.once('picker:cancel', () => {
if (picker && !picker.isDestroyed()) picker.close();
resolve(null);
});
picker.on('closed', () => resolve(null));
picker.loadURL(
'data:text/html;charset=utf-8,' +
encodeURIComponent(PICKER_HTML.replace('__ROWS__', rows))
);
picker.once('ready-to-show', () => picker.show());
});
})().finally(() => {
pickerPromise = null;
});
return pickerPromise;
}
/* ---------- window ---------- */
function createWindow() {
const win = new BrowserWindow({
width: 1200,
height: 820,
minWidth: 900,
minHeight: 600,
autoHideMenuBar: true,
backgroundColor: '#1e1f22',
title: 'OBI-1 · Open Battery Information',
show: false,
webPreferences: {
preload: path.join(__dirname, 'preload.js'),
contextIsolation: true,
nodeIntegration: false,
},
});
win.webContents.setWindowOpenHandler(({ url }) => {
if (url.startsWith('http')) shell.openExternal(url);
return { action: 'deny' };
});
win.webContents.on('did-fail-load', (_e, code, desc, url) => {
console.error('[main] did-fail-load', code, desc, url);
});
const target = path.join(SITE_DIR, 'obi.html');
console.log('[main] loading', target);
win.loadFile(target).then(
() => console.log('[main] page loaded'),
(err) => console.error('[main] loadFile failed:', err)
);
win.once('ready-to-show', () => {
console.log('[main] window ready-to-show');
win.show();
});
return win;
}
app.whenReady().then(() => {
console.log('[main] app ready');
if (process.platform !== 'darwin') {
Menu.setApplicationMenu(null);
}
try {
createWindow();
console.log('[main] window created');
} catch (err) {
console.error('[main] createWindow failed:', err);
}
app.on('activate', () => {
if (BrowserWindow.getAllWindows().length === 0) createWindow();
});
});
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') app.quit();
});