import cluster from 'cluster'
import * as os from 'os'
let numWorkers = os.cpus().length;
import fs from 'fs'
import fetch from 'node-fetch'

const listEndpointsToAttack = [
    // https://jsonplaceholder.typicode.com/users
    'https://jsonplaceholder.typicode.com/users/1',
    'https://jsonplaceholder.typicode.com/users/2',
    'https://jsonplaceholder.typicode.com/users/3',

    // https://jsonplaceholder.typicode.com/posts
    'https://jsonplaceholder.typicode.com/posts/1',
    'https://jsonplaceholder.typicode.com/posts/2',
    'https://jsonplaceholder.typicode.com/posts/3',

    // https://jsonplaceholder.typicode.com/comments
    'https://jsonplaceholder.typicode.com/comments/1',
    'https://jsonplaceholder.typicode.com/comments/2',
    'https://jsonplaceholder.typicode.com/comments/3',

    // https://jsonplaceholder.typicode.com/todos
    'https://jsonplaceholder.typicode.com/todos/1',
    'https://jsonplaceholder.typicode.com/todos/2',
    'https://jsonplaceholder.typicode.com/todos/3'
]

if (cluster.isPrimary) {
    console.log('Master cluster setting up ' + numWorkers + ' workers...');

    for (var i = 0; i < numWorkers; i++) {
        cluster.fork();
    }

    cluster.on('online', function (worker) {
        console.log('Worker ' + worker.process.pid + ' is online');
    });

    cluster.on('exit', function (worker, code, signal) {
        console.log('Worker ' + worker.process.pid + ' died with code: ' + code + ', and signal: ' + signal);
        console.log('Starting a new worker');
        cluster.fork();
    });
} else {

    let timetaken = `Tempo execução no Worker ID:  ${process.pid}`;

    let begin = Date.now();

    console.time(timetaken);

    let totalRequestsMade = 0

    const workerJobStatistics = {
        worker_id: null,
        worker_execution_time: null,
        total_requests_made: 0,
        total_requests_timeout: 0,
        total_requests_http_status_code_200: 0,
        total_requests_fail: 0,
        responses: []
    }

    for (let i = 1; i <= 20; i++) {

        workerJobStatistics.worker_id = process.pid

        for (let i = 0; i < listEndpointsToAttack.length; i++) {

            const request = {
                endpoint: null,
                http_status_code_response: null,
                response: null
            }

            totalRequestsMade += 1

            workerJobStatistics.total_requests_made += 1

            console.log('Worker ID: ' + process.pid + ` => Processing REQUEST GET: ${listEndpointsToAttack[i]} => ` + i)

            try {
                fetch(`${listEndpointsToAttack[i]}`)
                    .then((response) => {
                        if (response.status === 200) {
                            workerJobStatistics.total_requests_http_status_code_200 += 1
                            request.http_status_code_response = response.status
                            request.endpoint = response.url
                        }
                        return response
                    })
                    .then(response => response.json())
                    .then(response => {
                        if (response) {
                            request.response_success = response.success
                            request.response = response
                        }
                        return response
                    })
                    .then(response => {
                        console.log(response)
                        workerJobStatistics.responses.push(request)
                        try {
                            fs.writeFileSync(`./responses/responses-from-worker-id-${process.pid}.json`, JSON.stringify(workerJobStatistics), 'utf8');
                        } catch (error) {
                            console.log('An error has occurred ', error);
                        }
                    })
                    .catch(err => {
                        workerJobStatistics.total_requests_fail += 1
                        console.error(err)

                        try {
                            fs.writeFileSync(`./responses/responses-from-worker-id-${process.pid}.json`, JSON.stringify(workerJobStatistics), 'utf8');
                        } catch (error) {
                            console.error(err)
                        }
                    })
            } catch (err) {
                workerJobStatistics.total_requests_timeout += 1
                fs.writeFileSync(`./responses/responses-from-worker-id-${process.pid}.json`, JSON.stringify(workerJobStatistics), 'utf8');
            }
        }
    }

    console.timeEnd(timetaken);

    let end = Date.now();

    let timeSpent = (end - begin) / 1000 + " seconds";

    console.log(`-------> O Worker ID: ${process.pid} processou no total: ${totalRequestsMade} requisições `)

    setTimeout(function () {
        try {
            const jsonData = JSON.parse(fs.readFileSync(`./responses/responses-from-worker-id-${process.pid}.json`, 'utf-8'));
            jsonData.worker_execution_time = timeSpent
            console.log(`--> Tempo execução no Worker ID:  ${process.pid} => `, timeSpent)
            fs.writeFileSync(`./responses/responses-from-worker-id-${process.pid}.json`, JSON.stringify(jsonData, null, 4), 'utf8');
        } catch (error) {
            console.log('An error has occurred ', error);
        }
    }, 7500);
}