const VnObject = require('./object');
const kebabToCamel = require('./string-util').kebabToCamel;

let scopeUid = 0;

module.exports = new Class({
	Extends: VnObject

	,initialize: function(builder, objects, thisArg, parent) {
		this.builder = builder;
		this.objects = objects;
		this.thisArg = thisArg;
		this.parent = parent;
		this.uid = ++scopeUid;
		this.$ = parent ? Object.create(parent.$) : {};

		if (parent) {
			parent.on('lot-change', this.onLotChange, this);
			if (!thisArg) this.thisArg = parent.thisArg;
		}
	}
	
	,link: function(exprScope, extraObjects) {
		var contextMap = this.builder._contextMap;

		for (var id in extraObjects)
			this.$[id] = extraObjects[id];
		for (var id in contextMap)
			this.$[id] = this.objects[contextMap[id]];

		this.exprScope = [
			_,
			this.$
		].concat(exprScope);

		this.builder.link(this);
		this.builder.digest(this);

		for (const object of this.objects)
		if (object.assignLot)
			object.on('change', this.onLotChange, this);
	}

	,onLotChange() {
		this.emit('lot-change');
		this.builder.digest(this);
	}

	,getMain: function() {
		return this.builder.getMain(this);
	}
	
	,getById: function(objectId) {
		if (!objectId) return null;
		return this.$[kebabToCamel(objectId)];
	}
	
	,getByTagName: function(tagName) {
		return this.builder.getByTagName(this, tagName);
	}

	,getHtmlId: function(nodeId) {
		return 'vn-'+ this.uid +'-'+ nodeId;
	}
	
	,_destroy: function() {
		for (const object of this.objects)
		if (object instanceof VnObject) {
			object.disconnectByInstance(this);
			object.unref();
		}
		if (this.parent) {
			this.parent.disconnectByInstance(this);
			this.parent.unref();
		}

		VnObject.prototype._destroy.call(this);
	}
});