const { Worker } = require('worker_threads');
const fs = require('fs');
const path = require('path');

let totalSuccess = 0;
let totalError = 0;
const startTime = Date.now();

const logsDir = path.join(__dirname, 'logs');
if (!fs.existsSync(logsDir)) {
    fs.mkdirSync(logsDir);
}

const logFilePath = path.join(logsDir, `app-${new Date().toISOString().replace(/:/g, '-')}.log`);
const logger = () => {
    const timestamp = new Date().toISOString();
    return {
        info: (message) => fs.appendFileSync(logFilePath, `[${timestamp}] INFO:\t${message}\n`),
        error: (message) => fs.appendFileSync(logFilePath, `[${timestamp}] ERROR:\t${message}\n`),
        warn: (message) => fs.appendFileSync(logFilePath, `[${timestamp}] WARN:\t${message}\n`)
    }
};

module.exports = {
    logger,
    workerFactory: (
        workerData,
        onMessage = ({ id, payload }) => console.log("onMessage", id, payload),
        onError = ({ id, error }) => console.error("onError", id, error),
        onExit = ({ id, status }) => console.log("onExit", id, status)) => {
        return new Worker('./worker.js', { workerData })
            .on('message', (payload) => onMessage({ id: workerData.id, payload }))
            .on('error', (error) => onError({ id: workerData.id, error }))
            .on('exit', (status) => onExit({ id: workerData.id, status }));
    },
    onMessage: ({ id, payload }) => {
        switch (payload.status) {
            case 'starting':
                console.log(`${payload.id}\t⌛ Starting with url: ${payload.url}`);
                logger().info(`Worker ${payload.id} starting with url: ${payload.url}`);
                return;
            case 'success':
                totalSuccess++;
                break;
            case 'recoverable-error':
                totalError++;
                // Log recoverable errors to file
                logger().warn(`Worker ${id}: ${payload.error}`);
                break;
        }
        const totalRequests = totalError + totalSuccess;
        const timeDelta = Date.now() - startTime;
        const rps = totalRequests / (timeDelta / 1000);
        const successRate = (totalSuccess / totalRequests) * 100;
        process.stdout.write(`\r${id}\t🕒 Started: ${new Date(startTime).toISOString()} 📄 Requests: ${totalSuccess}/${totalRequests}. 📊 Success rate: ${successRate.toFixed(2)}%. ⚡ Req/s: ${rps.toFixed(2)}. ⏲️  Req/h: ${(rps * 3600).toFixed(2)}`);
    },
    onError: ({ id, error }) => {
        console.error(`\r${id}\t❌ ${error}. Total Successful Requests: ${totalSuccess}`);
        logger().error(`Worker ${id} critical error: ${error}`);
    },
    onExit: ({ id, status }) => {
        if (status !== 0) {
            console.error(`${id}\t❌ Exit status: ${status}`);
            logger().error(`Worker ${id} exited with status: ${status}`);
            return;
        }
        console.log(`${id}\t✅ Gracefully terminated.`);
        logger().info(`Worker ${id} gracefully terminated`);
    }
};