node-hci/lib/eventual/eventual-channel.js

/** Concept each channel can have child channels ??**/
const chs = ':'; // Channel separator

class XEvent {
	constructor(donecb,args) {
		this.count = 0;
		this.dowait = 0;
		
		this.done= donecb; // Callback
		this.errors = [];
		this.params = args;
	}
	wait() {
		this.dowait = 1;
	}
}

class EventualChannel {

	constructor(eventual, name,parent) {
		this.eventual = eventual;
		this.name = name;
		this.parent = parent; //?? we need
		
		this.childs = {}
		this.listeners = [];
	}

	// createChannel based on name
	//
	fullName() {
		var name = this.name;
		for(var cur = this;cur = cur.parent;cur.parent) {
			if(this.parent.parent) { // if not root
				name = this.parent.name +":" + name;
			}
		}
		return  name;
	}

	get2(name,create) {
		if(name == undefined) return this;

		var cur = this;	
		var [childName,...sub] = name.split(chs);
		
		if(cur.child[childName] == undefined) {
			if(!create) return null;
			cur.child[name] = new EventualChannel(this.eventual,name,this);
		}
		return this.get2(sub.join(chs),create);
	};

	// Should be private function
	get(name,create) {
		// How it should work?
		// Recursivelly get a listener why? because of match
		var nodes = name.split(chs);
		var cur = this;
		var ok = 1;

		nodes.forEach((v) => {
			if( cur.childs[v] == undefined) {
				if(create == undefined) { ok = false; return null; }
				cur.childs[v] = new EventualChannel(this.eventual,name,this);
			}
			cur = cur.childs[v]; // next;
		});

		if(!ok) return null;
		return cur;
	}
	channel(name) { // Will create channel and return new child channel
		return this.get(name,true);
	}
	// Get listeners
	search(name,create) {
		var channel	= this.get(name,create);
		if(channel) return channel.listeners;
		return [];
	}
	// Registers 
	// new listener
	on (name,cb,order) {
		var channel = this.channel(name);
		var listener = { name:name, callback:cb, order: order || 0 };
		channel.listeners.push(listener)

		// Check for state call
		var cname = channel.fullName();
		if(this.eventual._events.state[cname]!=undefined) {
			this.process([listener],this.eventual._events.state[cname]);
		}
		return this;
	}
	emit(name,args) {
		var tocall = this.search(name);
		return this.process(tocall,args);
	}

	//TODO: CLEAN THIS
	/*
	 * Basically process a list of functions and calls done in end
	 * */
	process(tocall,nargs) {
		var self=this;
	
		var args = nargs || [];	 // or empty
		// Common for all for now	
		var evt = new XEvent(next,args);

		var callback,dotrigger = 0;
		//Inner trigger	
		// Finish	
		function triggerDone() {
			if(callback) callback(evt);
			dotrigger = 1;
		}
		// Mem leak???
		var ret = {
			done: function(cb) {
				if(dotrigger) { cb(evt); }
				callback = cb;
			}
		}

		//this.stat.emitted++;
		// Sort
		tocall = tocall.sort((a,b) => {
			return (a.order - b.order) 
		});	
		// Get iter and setup evt
		var iter = tocall[Symbol.iterator]();
		
		function next() {
			process.nextTick(() => chain(iter));
		}

		// Internal thing
		function chain(iter) { 
			// Stack overflow risk? maybe put this in process.tick();
			var v = iter.next();
			if(v.done) {
				triggerDone(); // Done callback with evt only
				return;
			}
			// Create evt here with some global event chaining iteraction	
			try {
				var entry = v.value;
				evt.args = args;
				evt.name = entry.name;
				//self.stat.called++;
				entry.callback(...args,evt);
				evt.count++;
			}catch(e) {
				console.log(e);
				evt.errors.push(e);
				// Should we stop??
			}
			if(!evt.dowait) next();
			evt.dowait=0; // reset wait?
		}
		next();

		return ret;
	}


}

module.exports = EventualChannel;