/*\
title: $:/core/modules/widgets/eventcatcher.js
type: application/javascript
module-type: widget

Event handler widget

\*/
(function(){

/*jslint node: true, browser: true */
/*global $tw: false */
"use strict";

var Widget = require("$:/core/modules/widgets/widget.js").widget;

var EventWidget = function(parseTreeNode,options) {
	options.hasDom = true;
	this.initialise(parseTreeNode,options);
};

/*
Inherit from the base widget class
*/
EventWidget.prototype = new Widget();

/*
Render this widget into the DOM
*/
EventWidget.prototype.render = function(parent,nextSibling) {
	var self = this;
	// Remember parent
	this.parentDomNode = parent;
	// Compute attributes and execute state
	this.computeAttributes();
	this.execute();
	// Create element
	var tag = this.parseTreeNode.isBlock ? "div" : "span";
	if(this.elementTag && $tw.config.htmlUnsafeElements.indexOf(this.elementTag) === -1) {
		tag = this.elementTag;
	}
	var domNode = this.document.createElement(tag);
	this.domNode = domNode;
	// Assign classes
	this.assignDomNodeClasses();
	// Add our event handler
	$tw.utils.each(this.types,function(type) {
		domNode.addEventListener(type,function(event) {
			var selector = self.getAttribute("selector"),
				matchSelector = self.getAttribute("matchSelector"),
				actions = self.getAttribute("$"+type) || self.getAttribute("actions-"+type),
				stopPropagation = self.getAttribute("stopPropagation","onaction"),
				selectedNode = event.target,
				selectedNodeRect,
				catcherNodeRect,
				variables = {};
			// Firefox can fire dragover and dragenter events on text nodes instead of their parents
			if(selectedNode.nodeType === 3) {
				selectedNode = selectedNode.parentNode;
			}
			// Check that the selected node matches any matchSelector
			if(matchSelector && !$tw.utils.domMatchesSelector(selectedNode,matchSelector)) {
				return false;
			}
			if(selector) {
				// Search ancestors for a node that matches the selector
				while(!$tw.utils.domMatchesSelector(selectedNode,selector) && selectedNode !== domNode) {
					selectedNode = selectedNode.parentNode;
				}
				// Exit if we didn't find one
				if(selectedNode === domNode) {
					return false;
				}
				// Only set up variables if we have actions to invoke
				if(actions) {
					variables = $tw.utils.collectDOMVariables(selectedNode,self.domNode,event);
				}
			}
			// Execute our actions with the variables
			if(actions) {
				// Add a variable for the modifier key
				variables.modifier = $tw.keyboardManager.getEventModifierKeyDescriptor(event);
				// Add a variable for the mouse button
				if("button" in event) {
					if(event.button === 0) {
						variables["event-mousebutton"] = "left";
					} else if(event.button === 1) {
						variables["event-mousebutton"] = "middle";
					} else if(event.button === 2) {
						variables["event-mousebutton"] = "right";
					}
				}
				variables["event-type"] = event.type.toString();
				if(typeof event.detail === "object" && !!event.detail) {
					$tw.utils.each(event.detail,function(detailValue,detail) {
						variables["event-detail-" + detail] = detailValue.toString();
					});
				} else if(!!event.detail) {
					variables["event-detail"] = event.detail.toString();
				}
				self.invokeActionString(actions,self,event,variables);
			}
			if((actions && stopPropagation === "onaction") || stopPropagation === "always") {
				event.preventDefault();
				event.stopPropagation();
				return true;
			}
			return false;
		},false);
	});
	// Insert element
	parent.insertBefore(domNode,nextSibling);
	this.renderChildren(domNode,null);
	this.domNodes.push(domNode);
};

/*
Compute the internal state of the widget
*/
EventWidget.prototype.execute = function() {
	var self = this;
	// Get attributes that require a refresh on change
	this.types = [];
	$tw.utils.each(this.attributes,function(value,key) {
		if(key.charAt(0) === "$") {
			self.types.push(key.slice(1));
		}
	});
	if(!this.types.length) {
		this.types = this.getAttribute("events","").split(" ");
	}
	this.elementTag = this.getAttribute("tag");
	// Make child widgets
	this.makeChildWidgets();
};

EventWidget.prototype.assignDomNodeClasses = function() {
	var classes = this.getAttribute("class","").split(" ");
	classes.push("tc-eventcatcher");
	this.domNode.className = classes.join(" ");
};

/*
Selectively refreshes the widget if needed. Returns true if the widget or any of its children needed re-rendering
*/
EventWidget.prototype.refresh = function(changedTiddlers) {
	var changedAttributes = this.computeAttributes(),
		changedAttributesCount = $tw.utils.count(changedAttributes);
	if(changedAttributesCount === 1 && changedAttributes["class"]) {
		this.assignDomNodeClasses();
	} else if(changedAttributesCount > 0) {
		this.refreshSelf();
		return true;
	}
	return this.refreshChildren(changedTiddlers);
};

exports.eventcatcher = EventWidget;

})();