bully.js

const zerorpc = require('zerorpc');
const fs = require('fs');
const sleep = require('sleep');
const promiseFinally = require('promise.prototype.finally');
//nvm use v8.11.2

promiseFinally.shim();

class State {
	constructor() {
		//State of the node
		// [Down, Election, Reorganization, Normal]
		this.state = 'Normal';
		// coordinator of the node (if coordinator, has it's own id. Otherwise the id of the coordinator node)
		this.coord = 0;
		// The node which recently made this node halt (election started by a higher priority node)
		this.halt = -1;
		// list of nodes which this node believes to be in operation
		this.Up = [];
	}
}

var Bully = new Object(); //Create a new Bully Object
Bully.S = new State(); //assign a new State Object to Bully.S
Bully.S.state = 'Normal'; //set Bully.S.state to Normal (redundant)

Bully.checkServerPool = null; //empty pool

const address = process.argv[2]; //get server + port
Bully.addr = address; //assign it
Bully.config_file = 'server_config_local'; //confile file name

Bully.servers = []; //empty array of servers

//read config_file, put the content to an array, trim it and sort it
let f = fs.readFileSync(Bully.config_file, 'utf8').trim().split('\n').sort();
Bully.servers = f.slice(); //f is assigned to Bully.servers
console.log(`My addr: ${Bully.addr}`);
console.log(`Server list: ${Bully.servers}`);

Bully.connections = []; //empty Bully.connections Array

// Assigning priority varirable based on the order in the list
for (let i = 0; i < Bully.servers.length; i++) {
	if (Bully.servers[i] == Bully.addr) { // if the server in the list is the one my script is running...
		Bully.priority = i; //assign i to its priority
		Bully.connections.push(Bully); //push it to the connections array
	} else { //else
		let c = new zerorpc.Client(); // create new client which will communicate with other servers from the list
		c.connect('tcp://' + Bully.servers[i]); //connect it
		// console.log(`Binding server ${Bully.servers[i]}`);
		Bully.connections.push(c); //push new client
		// console.log(c)
	}
}


//Bully Methods
Bully.areYouThere = function(param, reply) { //when areYouThere is called by a client,
	console.log('METHOD INVOKED!!!!!!!!!!!!!!');
	//return true
	reply(null, true); //return True using ZeroRPC Method
};

Bully.areYouNormal = function(param, reply) {
	console.log('METHOD INVOKED!!!!!!!!!!!!!!');
	if (this.S.state == 'Normal') {
		// return true
		reply(null, true);
	} else {
		// return false
		reply(null, false);
	}
};

Bully.halt = function(number, reply) { //When halt is called...
	this.S.state = 'Election'; // we change the state of this server to Election
	this.S.halt = number; //and change this.S.halt to the number given
	reply(null, true);
};

Bully.newCoordinator = function(nb) { //When newCoordinator is called
	console.log('call newCoordinator');
	if (this.S.halt == nb && this.S.state == 'Election') { //if this.S.halt is True and this.S.state is Election
		this.S.coord = nb; // we give this.S.coord the nb given as parameter
		this.S.state = 'Reorganization'; // and change this.S.state to 'Reorganization'
	}
};

Bully.ready = function(nb, x = null) { //When ready is called...
	console.log('call ready');
	if (this.S.coord == nb && this.S.state == 'Reorganization') { //if this.S.coord == nb AND we have reorganization State,
		//this.S.d = x;
		this.S.state = 'Normal'; //Set the state back to Normal
	}
};

Bully.syncFuncCall = function(func_name, client_test, param=null) {
	return new Promise((resolve, reject) => {
		// console.log()
		client_test.invoke(func_name, param, function(error, res, more) {
			if (error || !res) {
				// return reject(error);
				reject(error);
				// return reject();
			} else {
				// return resolve(res);
				resolve(res);
			}

		});
	});
}

Bully.election = function() { // When election is called...
	console.log('Check the states of higher priority nodes');

	let priorityPlusOne = this.priority + 1; // Priority + 1
	let restOfElements = this.servers.slice(priorityPlusOne); //list of elements from priorityPlusOne to the end
	// console.log(this.priority)
	for (let i = 0; i < restOfElements.length+1; i++) {
			this.syncFuncCall("areYouThere", this.connections[priorityPlusOne+i], null)
				.then((resp) => {
					// console.log(this.priority+1+i)
					console.log(`resolved: ${resp}`);
					if (this.checkServerPool == null) {
						this.S.coord = this.priority + 1 + i; // change this.S.coord to priority +1 + value of index
						this.S.state = 'Normal'; // change state to Normal
						this.checkServerPool = "something";
						// this.check();                                      // call check()
					}
					return;
				})
				.catch(() => {
					if(i!=restOfElements.length){
						console.log(`${restOfElements[i]} Timeout 1! Server offline, can't choose this as a coordinator`);
					}
					else{
						console.log('halt all lower priority nodes including this node:');
						// this.individualHalt(this.priority); //
						console.log(`${this.servers[this.priority]}: I halted myself`)
						this.S.state = 'Election';
						console.log(`I am ${this.S.state}`);
						this.S.halt = this.priority;
						this.S.Up = [];
						this.S.Up.push(this);
						var counter = 0;
						for (let j = 0; j < this.priority; j++) {
									this.syncFuncCall("halt", this.connections[j], this.priority)
										.then(()=>{
											console.log(`Prompt: ${this.servers[j]} server halted successfully`);
										})
										.catch(()=>{

											console.log(`Prompt: ${this.servers[j]} Timeout 2, server not reachable, cannot halt`);
											// continue;
										})
										.finally(() =>{
											this.S.Up.push(this.connections[j]);
											if(counter == this.servers.length-2){
												console.log("inform all nodes of new coordinator");
												this.S.coord = this.priority;
												this.S.State = "Reorganization";
												var counter2 = 0;
												for(let k = 0;k<this.S.Up.length;k++){
													if (this.servers[this.priority]!=this.servers[k]){
														this.syncFuncCall("newCoordinator", this.S.Up[k], this.priority)
															.then(()=>{
																console.log(`Prompt: ${this.servers[k]} server received new coordinator`);
															})
															.catch(()=>{
																console.log(`Prompt: ${this.servers[k]} Timeout 3, server not reachable, election has to be restarted`);
																// this.election();
															})
															.finally(() => {
																console.log(counter2)
																if(counter2==this.servers.length-2){
																	var counter3 = 0;
																	for(let l=0;l<this.S.Up.length;l++){
																		if (this.servers[this.priority]!=this.servers[l]){
																			this.syncFuncCall("ready", this.S.Up[l], this.priority)
																				.then(()=>{
																					console.log(`Prompt: ${this.servers[l]} server is ready (not coordinator)`);
																				})
																				.catch(()=>{
																					console.log(`Prompt: ${this.servers[l]} Timeout 4, server lost connection, election has to be restarted`);
																					// this.election();
																				}).finally(()=>{
																					if(counter3==this.servers.length-2){
																						// this.check();
																						console.log("implement check!!!")
																					}
																					counter3++;
																				});
																		} else {
																			this.S.state = "Normal";
																		}
																	}
																}
																counter2++;
															});
													}
												}
											}
											counter++;
										});
						}
					}
					
				})
	}
}		


Bully.recovery = function() {
	this.S.halt = -1;
	this.election();
};

Bully.check = function() {
	while (true) {
		console.log('My address is ', this.addr);
		if (this.S.coord == this.priority) {
			console.log('I am Coordinator');
		} else {
			console.log('I am Normal');
		}
		sleep.sleep(5);
		if (this.S.state == 'Normal' && this.S.coord == this.priority) {

			for (let i = 0; i < this.servers.length; i++) {
				if (i != this.priority) {
			// 		try {
			// 			// console.log(this.connections[i])
			// 			if (this.connections[i].invoke('areYouThere', function(error, res, more) {
			// 					return res;
			// 				}) == undefined) {
			// 				throw error;
			// 			} else {
			// 				var ans = this.connections[i].invoke('areYouNormal', function(error, res, more) {
			// 					return res;
			// 				});
			// 			}
			// 		} catch (error) {
			// 			// console.log(error);
			// 			console.log(`${this.servers[i]} Timeout! 5 (normal node unreachable)`);
			// 			continue;
			// 			// return;
			// 		}
			// 		if (!ans) {
			// 			this.election();
			// 			return;
			// 		}
			// 	}
			// }
		
				} else if (this.S.state == 'Normal' && this.S.coord != this.priority) {
					console.log('check coordinator\'s state');
					this.syncFuncCall("areYouThere", this.connections[this.S.coord])
						.then(()=>{
							console.log(`Prompt: ${this.servers[this.S.coord]} coordinator is up`);
						})
						.catch(()=>{
							console.log(`Prompt: ${this.servers[this.S.coord]} coordinator down, start election`);
							// this.timeout();
						});
				}
			}
		}
	}
};

Bully.timeout = function() {
	if (this.S.state == 'Normal' || this.S.state == 'Reorganization') {
		this.syncFuncCall("areYouThere", this.connections[this.S.coord])
			.then(()=>{
				console.log(`Prompt: ${this.servers[this.S.coord]} coordinator alive`);
			})
			.catch(()=>{
				console.log(`Prompt: ${this.servers[this.S.coord]} Timeout 6, coordinator down, start election`);
				// this.election();
			});
	} else {
		console.log("starting election");
		// this.election();
	}
};

Bully.inititialize = function() {
	this.recovery();

};

const s = new zerorpc.Server(Bully);
s.bind('tcp://' + address);
Bully.inititialize();
console.log(`${address} initializing Server`);