class HeartManager {

	constructor() {
		this.countHearts = HeartManager.DEFAULT_MAX_COUNT;
		this.countMaxHearts = HeartManager.DEFAULT_MAX_COUNT;

		this.onChangeHeartListeners = [];
		this.onChangeGameOverListeners = [];
	}

	callListener(functionArray) {
		if(functionArray.length > 0) {
			for(let i = 0; i < functionArray.length; i++) {
				functionArray[i](this.score);
			}
		}
	}

	addOnChangeHeartListener(onChangeFunction) {
		this.onChangeHeartListeners.push(onChangeFunction);
	}

	removeOnChangeHeartListener(onChangeFunction) {
		let itemIndex = this.onChangeHeartListeners.indexOf(onChangeFunction);
		if(itemIndex > -1)
			this.onChangeHeartListeners.splice(itemIndex, 1);
	}

	addOnChangeGameOverListener(onChangeGameOverFunction) {
		this.onChangeGameOverListeners.push(onChangeGameOverFunction);
	}

	removeOnChangeHighScoreListener(onChangeGameOverFunction) {
		let itemIndex = this.onChangeGameOverListeners.indexOf(onChangeGameOverFunction);
		if(itemIndex > -1)
			this.onChangeGameOverListeners.splice(itemIndex, 1);
	}

	removeAllListeners() {
		this.onChangeHeartListeners = [];
		this.onChangeGameOverListeners = [];
	}


	setHearts(amount) {
		let beforeCountHearts = this.countHearts;
		this.countHearts = amount;
		if(this.countHearts < 0)
			this.countHearts = 0;
		else if(this.countHearts > this.countMaxHearts)
			this.countHearts = this.countMaxHearts;

		if(beforeCountHearts !== this.countHearts)
			this.callListener(this.onChangeHeartListeners);

		if(this.countHearts === 0)
			this.callListener(this.onChangeGameOverListeners);
	}

	setMaxHearts(amount) {
		this.countMaxHearts = amount;

		if(this.countHearts > this.countMaxHearts)
			this.countHearts = this.countMaxHearts;
	}

	getHearts() {
		return this.countHearts;
	}

	addHearts(amount) {
		this.setHearts(this.countHearts + amount);

	}

	breakHearts(amount) {
		this.addHearts(-1 * amount);
	}

	setScore(value) {
		let beforeScore = this.score;
		this.score = value;

		// update score
		if(beforeScore !== this.score)
			this.callListener(this.onChangeHeartListeners);

		// update high score
		if(this.score > this.highScore)
			this.callListener(this.onChangeGameOverListeners);
	}

}

HeartManager.DEFAULT_MAX_COUNT		= 3;