app.js

require('dotenv').config();

const config = require('./config'),
    cors = require('cors'),
    express = require('express'),
    exphbs = require('express-handlebars'),
    getDayjs = require('./services/dayjs-wrapper'),
    jsonStore = require('./services/json-store'),
    stats = require('./services/stats'),
    morgan = require('morgan'),
    removeExpiredSubscriptions = require('./services/remove-expired-subscriptions'),
    websocket = require('./services/websocket');

let app, hbs, server, dayjs;

console.log(`${config.appName} ${config.appVersion}`);

// Schedule cleanup tasks
function scheduleCleanupTasks() {
    // Run cleanup immediately on startup
    removeExpiredSubscriptions()
        .then(() => console.log('Startup subscription cleanup completed'))
        .catch(err => console.error('Error in startup subscription cleanup:', err));

    // Run subscription cleanup every 24 hours
    setInterval(async() => {
        try {
            console.log('Running scheduled subscription cleanup...');
            await removeExpiredSubscriptions();
        } catch (error) {
            console.error('Error in scheduled subscription cleanup:', error);
        }
    }, 24 * 60 * 60 * 1000); // 24 hours in milliseconds
}

morgan.format('mydate', () => {
    return new Date().toLocaleTimeString('en-US', { hour12: false, fractionalSecondDigits: 3 }).replace(/:/g, ':');
});

// Initialize dayjs at startup
async function initializeDayjs() {
    dayjs = await getDayjs();
}

app = express();

app.set('trust proxy', true);

app.use(morgan('[:mydate] :method :url :status :res[content-length] - :remote-addr - :response-time ms'));

app.use(cors());

// Configure handlebars template engine to work with dayjs
hbs = exphbs.create({
    helpers: {
        formatDate: (datetime, format) => {
            return dayjs(datetime).format(format);
        }
    }
});

// Configure express to use handlebars
app.engine('handlebars', hbs.engine);
app.set('view engine', 'handlebars');

// Handle static files in public directory
app.use(express.static('public', {
    dotfiles: 'ignore',
    maxAge: '1d'
}));

// Load controllers
app.use(require('./controllers'));

async function gracefulShutdown() {
    jsonStore.shutdown();
    process.exit();
}

process.on('SIGINT', gracefulShutdown);
process.on('SIGTERM', gracefulShutdown);

// Persist data before dying on an unexpected error
process.on('uncaughtException', (error) => {
    console.error('Uncaught exception, flushing data store before exit:', error);
    jsonStore.shutdown();
    process.exit(1);
});

process.on('unhandledRejection', (reason) => {
    console.error('Unhandled promise rejection, flushing data store before exit:', reason);
    jsonStore.shutdown();
    process.exit(1);
});

async function startServer() {
    await initializeDayjs();

    jsonStore.initialize(config.dataFilePath);

    // Start cleanup scheduling
    scheduleCleanupTasks();

    // Generate stats on startup, then schedule periodic regeneration
    stats.generateStats().catch(err => console.error('Error generating initial stats:', err));
    stats.scheduleStatsGeneration();

    server = app.listen(config.port, () => {
        app.locals.host = config.domain;
        app.locals.port = server.address().port;

        if (app.locals.host.indexOf(':') > -1) {
            app.locals.host = '[' + app.locals.host + ']';
        }

        // Initialize WebSocket server for /wsLog
        websocket.initialize(server);

        console.log(`Listening at http://${app.locals.host}:${app.locals.port}`);
    })
        .on('error', (error) => {
            switch (error.code) {
            case 'EADDRINUSE':
                console.log(`Error: Port ${config.port} is already in use.`);
                break;
            default:
                console.log(error.code);
            }
        });
}

startServer().catch(console.error);