/** @type {import('node:cluster').Cluster} */
const cluster = require("cluster");
const os = require("os");

/**
 * Use Round Robin algorithm for cluster process load balancer
 */
cluster.schedulingPolicy = cluster.SCHED_RR;

async function main()
{
    if(cluster.isPrimary == false)
    {
        // This process is a worker / slave
        // Compile source code and run
        require("./Source/index");
        // stay here
        return;
    };

    // This process is a primary / master

    // Worker process list
    const master = new Map();

    const coreCount = 2 // os.cpus().length;
    for(let index = 0; index < coreCount; index++)
    {
        // Open slave process
        let worker = await generateFlow();
        // Save process with id
        master.set(worker.id, worker);
        // Listen process for commands
        worker.message(
            // This process want to send payload to sibling process with IPC
            (workerId, payload) =>{
                for (const [siblingWorkerId,{send}] of master) {
                    // No sending to itself
                    if(workerId !== siblingWorkerId)
                    {
                        // Send command to sibling with IPC
                        send({
                            ...payload,
                            pid: worker.id
                        })
                    }
                }
            }
        )
    }
}




async function generateFlow(N)
{
    // Mirror this process with for (low-level os multitasking)
    const worker = cluster.fork();
    // Wait process is online
    await new Promise(ok => {
        worker.addListener("online",()=> {
            ok()
        })
    });
    // Get process pid on the os
    let id = worker.process.pid;
    
    // Simplification wrapping send and get events with IPC's event functions
    return {
        id,
        send: message => worker.send(message),
        message: (callback) => worker.addListener("message", e => callback(id,e))
    }
}

// Run immediately
process.nextTick(main);