ReasonSwitch.js

var ReasonSwitch = function(reasons) {
	this.on = !!reasons.length;
	this.reasons = reasons; //reasons

	this.bias = 'off'; //implement later, are reasons to stay on or off

	this.on = function(reason) {
		var reasons = this.reasons;

		var switched = false; //default

		if(!reasons.length) {
			this.on = false;
			switched = true;
		}

		if(reasons.indexOf(reason) === false) {
			reasons.push(reason);
			this.reasons = reasons;
		}

		return switched;
	};

	this.off = function(reason) {
		var reasons = this.reasons;
		var switched = false; //default
		if(reasons.indexOf(reason) !== false) {
			var index = reasons.indexOf(reason);
			reasons.splice(index, 1);
			this.reasons = reasons;

			if(!reasons.length) {
				this.on = true;
				switched = true;
			}
		}

		return switched;
	};
};