/**
 * EGroupware eTemplate2 - JS DOM Widget class
 *
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package etemplate
 * @subpackage api
 * @link http://www.egroupware.org
 * @author Andreas Stöckel
 * @copyright Stylite 2011
 * @version $Id$
 */

"use strict";

/*egw:uses
	et2_core_interfaces;
	et2_core_widget;
	/phpgwapi/js/egw_action/egw_action.js;
*/

/**
 * Abstract widget class which can be inserted into the DOM. All widget classes
 * deriving from this class have to care about implementing the "getDOMNode"
 * function which has to return the DOM-Node.
 * 
 * @augments et2_widget
 */
var et2_DOMWidget = et2_widget.extend(et2_IDOMNode, 
{
	attributes: {
		"disabled": {
			"name": "Disabled",
			"type": "boolean",
			"description": "Defines whether this widget is visible.  Not to be confused with an input widget's HTML attribute 'disabled'.",
			"default": false
		},
		"width": {
			"name": "Width",
			"type": "dimension",
			"default": et2_no_init,
			"description": "Width of the element in pixels, percentage or 'auto'"
		},
		"height": {
			"name": "Height",
			"type": "dimension",
			"default": et2_no_init,
			"description": "Height of the element in pixels, percentage or 'auto'"
		},
		"class": {
			"name": "CSS Class",
			"type": "string",
			"default": et2_no_init,
			"description": "CSS Class which is applied to the dom element of this node"
		},
		"overflow": {
			"name": "Overflow",
			"type": "string",
			"default": et2_no_init,
			"description": "If set, the css-overflow attribute is set to that value"
		},
		"parent_node": {
			"name":	"DOM parent",
			"type": "string",
			"default": et2_no_init,
			"description": "Insert into the target DOM node instead of the normal location"
		},
		"actions": {
			"name": "Actions list",
			"type": "any",
			"default": et2_no_init,
			"description": "List of egw actions that can be done on the widget.  This includes context menu, drag and drop.  TODO: Link to action documentation"
		},
	},

	/**
	 * When the DOMWidget is initialized, it grabs the DOM-Node of the parent
	 * object (if available) and passes it to its own "createDOMNode" function
	 * 
	 * @memberOf et2_DOMWidget
	 */
	init: function() {
		// Call the inherited constructor
		this._super.apply(this, arguments);

		this.parentNode = null;

		this._attachSet = {
			"node": null,
			"parent": null
		};

		this.disabled = false;
		this._surroundingsMgr = null;
	},

	/**
	 * Detatches the node from the DOM and clears all references to the parent
	 * node or the dom node of this widget.
	 */
	destroy: function() {

		this.detachFromDOM();
		this.parentNode = null;
		this._attachSet = {};

		if (this._surroundingsMgr)
		{
			this._surroundingsMgr.free();
			this._surroundingsMgr = null;
		}

		this._super();
	},

	/**
	 * Attaches the container node of this widget to the DOM-Tree
	 */
	doLoadingFinished: function() {
		// Check whether the parent implements the et2_IDOMNode interface. If
		// yes, grab the DOM node and create our own.
		if (this._parent && this._parent.implements(et2_IDOMNode)) {
			if(this.options.parent_node)
			{
				this.set_parent_node(this.options.parent_node);
			}
			else
			{
				this.setParentDOMNode(this._parent.getDOMNode(this));
			}
		}

		return true;
	},

	/**
	 * Detaches the widget from the DOM tree, if it had been attached to the
	 * DOM-Tree using the attachToDOM method.
	 */
	detachFromDOM: function() {

		if (this._attachSet.node && this._attachSet.parent)
		{
			// Remove the current node from the parent node
			try {
				this._attachSet.parent.removeChild(this._attachSet.node);
			} catch (e) {
				// Don't throw a DOM error if the node wasn't in the parent
			}

			// Reset the "attachSet"
			this._attachSet = {
				"node": null,
				"parent": null
			};

			return true;
		}

		return false;
	},

	/**
	 * Attaches the widget to the DOM tree. Fails if the widget is already
	 * attached to the tree or no parent node or no node for this widget is
	 * defined.
	 */
	attachToDOM: function() {
		// Attach the DOM node of this widget (if existing) to the new parent
		var node = this.getDOMNode(this);
		if (node && this.parentNode &&
		    (node != this._attachSet.node ||
		    this.parentNode != this._attachSet.parent))
		{
			// If the surroundings manager exists, surround the DOM-Node of this
			// widget with the DOM-Nodes inside the surroundings manager.
			if (this._surroundingsMgr)
			{
				node = this._surroundingsMgr.getDOMNode(node);
			}

			// Append this node at its index
			var idx = this.getDOMIndex();
			if (idx < 0 || idx >= this.parentNode.childNodes.length - 1)
			{
				this.parentNode.appendChild(node);
			}
			else
			{
				this.parentNode.insertBefore(node, this.parentNode.childNodes[idx]);
			}

			// Store the currently attached nodes
			this._attachSet = {
				"node": node,
				"parent": this.parentNode
			};

			return true;
		}

		return false;
	},

	isAttached: function() {
		return this.parentNode != null;
	},

	getSurroundings: function() {
		if (!this._surroundingsMgr)
		{
			this._surroundingsMgr = new et2_surroundingsMgr(this);
		}

		return this._surroundingsMgr;
	},

	/**
	 * Set the parent DOM node of this element.  Takes a wider variety of types
	 * than setParentDOMNode(), and matches the set_<attribute> naming convention.
	 *
	 * @param _node String|DOMNode DOM node to contain the widget, or the ID of the DOM node.
	 */
	set_parent_node: function(_node) {
		if(typeof _node == "string")
		{
			this.setParentDOMNode($j('#'+_node).get(0));
		}
		else
		{
			this.setParentDOMNode(_node);
		}
	},

	/**
	 * Set the parent DOM node of this element. If another parent node is already
	 * set, this widget removes itself from the DOM tree
	 */
	setParentDOMNode: function(_node) {
		if (_node != this.parentNode)
		{
			// Detatch this element from the DOM tree
			this.detachFromDOM();

			this.parentNode = _node;

			// And attatch the element to the DOM tree
			this.attachToDOM();
		}
	},

	/**
	 * Returns the parent node.
	 */
	getParentDOMNode: function() {
		return this.parentNode;
	},

	/**
	 * Returns the index of this element in the DOM tree
	 */
	getDOMIndex: function() {
		if (this._parent)
		{
			var idx = 0;
			var children = this._parent.getChildren();

			for (var i = 0; i < children.length; i++)
			{
				if (children[i] == this)
				{
					return idx;
				}
				else if (children[i].isInTree())
				{
					idx++;
				}
			}
		}

		return -1;
	},

	/**
	 * Sets the id of the DOM-Node.
	 */
	set_id: function(_value) {

		this.id = _value;

		var node = this.getDOMNode(this);
		if (node)
		{
			if (_value != "")
			{
				node.setAttribute("id", this.getInstanceManager().uniqueId+'_'+this.id);
			}
			else
			{
				node.removeAttribute("id");
			}
		}
	},

	set_disabled: function(_value) {
		var node = this._surroundingsMgr != null ? this._surroundingsMgr.getDOMNode(this.getDOMNode(this)) : this.getDOMNode(this);
		if (node && this.disabled != _value)
		{
			this.disabled = _value;

			if (_value)
			{
				$j(node).hide();
			}
			else
			{
				$j(node).show();
			}
		}
	},

	set_width: function(_value) {
		this.width = _value;

		var node = this.getDOMNode(this);
		if (node)
		{
			$j(node).css("width", _value);
		}
	},

	set_height: function(_value) {
		this.height = _value;

		var node = this.getDOMNode(this);
		if (node)
		{
			$j(node).css("height", _value);
		}
	},

	set_class: function(_value) {
		var node = this.getDOMNode(this);
		if (node)
		{
			if (this["class"])
			{
				$j(node).removeClass(this["class"]);
			}
			$j(node).addClass(_value);
		}

		this["class"] = _value;
	},

	set_overflow: function(_value) {
		this.overflow = _value;

		var node = this.getDOMNode(this);
		if (node)
		{
			$j(node).css("overflow", _value);
		}
	},

	/**
	 * Set Actions on the widget
	 *
	 * Each action is defined as an object:
	 *
	 * move: {
	 *      type: "drop",
	 *      acceptedTypes: "mail",
	 *      icon:   "move",
	 *      caption:	"Move to"
	 *      onExecute:      javascript:mail_move"
	 * }
	 *
	 * This will turn the widget into a drop target for "mail" drag types.  When "mail" drag types are dropped,
	 * the global function mail_move(egwAction action, egwActionObject sender) will be called.  The ID of the
	 * dragged "mail" will be in sender.id, some information about the sender will be in sender.context.  The
	 * etemplate2 widget involved can typically be found in action.parent.data.widget, so your handler
	 * can operate in the widget context easily.  The location varies depending on your action though.  It
	 * might be action.parent.parent.data.widget
	 *
	 * To customise how the actions are handled for a particular widget, override _link_actions().  It handles
	 * the more widget-specific parts.
	 *
	 * @param Object {ID: {attributes..}+} map of egw action information
	 * @see etemplate/inc/class.etemplate_widget_nextmatch->egw_actions()
	 */
	set_actions: function(actions)
	{
		if(this.id == "" || typeof this.id == "undefined")
		{
			this.egw().debug("warn", "Widget should have an ID if you want actions",this);
			return;
		}

		// Initialize the action manager and add some actions to it
		var gam = egw_getAppActionManager();
		if(typeof this._actionManager != "object")
		{
			if(gam.getActionById(this.id) != null)
			{
				this._actionManager = gam.getActionById(this.id);
			}
			else
			{
				this._actionManager = gam.addAction("actionManager", this.id);
			}
		}
		this._actionManager.updateActions(actions);

		// Put a reference to the widget into the action stuff, so we can
		// easily get back to widget context from the action handler
		this._actionManager.data = {widget: this};

		// Link the actions to the DOM
		this._link_actions(actions);
	},
	
	/**
	 * Get all action-links / id's of 1.-level actions from a given action object
	 * 
	 * This can be overwritten to not allow all actions, by not returning them here.
	 * 
	 * @param actions
	 * @returns {Array}
	 */
	_get_action_links: function(actions)
	{
		var action_links = [];
		for(var i in actions)
		{
			var action = actions[i];
			action_links.push(typeof action.id != 'undefined' ? action.id : i);
		}
		return action_links;
	},

	/**
	 * Link the actions to the DOM nodes / widget bits.
	 *
	 */
	_link_actions: function(actions)
	{
		 // Get the top level element for the tree
		var objectManager = egw_getAppObjectManager(true);
		var widget_object = objectManager.getObjectById(this.id);
		if (widget_object == null) {
			// Add a new container to the object manager which will hold the widget
			// objects
			widget_object = objectManager.insertObject(false, new egwActionObject(
				this.id, objectManager, new et2_action_object_impl(this),
				objectManager.manager.getActionById(this.id) || objectManager.manager
			));
		}

		// Delete all old objects
		widget_object.clear();

		// Go over the widget & add links - this is where we decide which actions are
		// 'allowed' for this widget at this time
		var action_links = this._get_action_links(actions);
		widget_object.updateActionLinks(action_links);
	}
});

/**
 * The surroundings manager class allows to append or prepend elements around
 * an widget node.
 * 
 * @augments Class
 */
var et2_surroundingsMgr = Class.extend(
{
	/**
	 * Constructor
	 * 
	 * @memberOf et2_surroundingsMgr
	 * @param _widget
	 */
	init: function(_widget) {
		this.widget = _widget;

		this._widgetContainer = null;
		this._widgetSurroundings = [];
		this._widgetPlaceholder = null;
		this._widgetNode = null;
		this._ownPlaceholder = true;
	},

	destroy: function() {
		this._widgetContainer = null;
		this._widgetSurroundings = null;
		this._widgetPlaceholder = null;
		this._widgetNode = null;
	},

	prependDOMNode: function(_node) {
		this._widgetSurroundings.unshift(_node);
		this._surroundingsUpdated = true;
	},

	appendDOMNode: function(_node) {
		// Append an placeholder first if none is existing yet
		if (this._ownPlaceholder && this._widgetPlaceholder == null)
		{
			this._widgetPlaceholder = document.createElement("span");
			this._widgetSurroundings.push(this._widgetPlaceholder);
		}

		// Append the given node
		this._widgetSurroundings.push(_node);
		this._surroundingsUpdated = true;
	},

	insertDOMNode: function(_node) {
		if (!this._ownPlaceholder || this._widgetPlaceholder == null)
		{
			this.appendDOMNode(_node);
			return;
		}

		// Get the index of the widget placeholder and delete it, insert the
		// given node instead
		var idx = this._widgetSurroundings.indexOf(this._widgetPlaceholder);
		this._widgetSurroundings.splice(idx, 1, _node);

		// Delete the reference to the own placeholder
		this._widgetPlaceholder = null;
		this._ownPlaceholder = false;
	},

	removeDOMNode: function(_node) {
		for (var i = 0; i < this._widgetSurroundings.length; i++)
		{
			if (this._widgetSurroundings[i] == _node)
			{
				this._widgetSurroundings.splice(i, 1);
				this._surroundingsUpdated = true;
				break;
			}
		}
	},

	setWidgetPlaceholder: function(_node) {
		if (_node != this._widgetPlaceholder)
		{
			if (_node != null && this._ownPlaceholder && this._widgetPlaceholder != null)
			{
				// Delete the current placeholder which was created by the
				// widget itself
				var idx = this._widgetSurroundings.indexOf(this._widgetPlaceholder);
				this._widgetSurroundings.splice(idx, 1);

				// Delete any reference to the own placeholder and set the
				// _ownPlaceholder flag to false
				this._widgetPlaceholder = null;
				this._ownPlaceholder = false;
			}
			
			this._ownPlaceholder = (_node == null);
			this._widgetPlaceholder = _node;
			this._surroundingsUpdated = true;
		}
	},

	_rebuildContainer: function() {
		// Return if there has been no change in the "surroundings-data"
		if (!this._surroundingsUpdated)
		{
			return false;
		}

		// Build the widget container
		if (this._widgetSurroundings.length > 0)
		{
			// Check whether the widgetPlaceholder is really inside the DOM-Tree
			var hasPlaceholder = et2_hasChild(this._widgetSurroundings,
				this._widgetPlaceholder);

			// If not, append another widget placeholder
			if (!hasPlaceholder)
			{
				this._widgetPlaceholder = document.createElement("span");
				this._widgetSurroundings.push(this._widgetPlaceholder);

				this._ownPlaceholder = true;
			}

			// If the surroundings array only contains one element, set this one
			// as the widget container
			if (this._widgetSurroundings.length == 1)
			{
				if (this._widgetSurroundings[0] == this._widgetPlaceholder)
				{
					this._widgetContainer = null;
				}
				else
				{
					this._widgetContainer = this._widgetSurroundings[0];
				}
			}
			else
			{
				// Create an outer "span" as widgetContainer
				this._widgetContainer = document.createElement("span");

				// Append the children inside the widgetSurroundings array to
				// the widget container
				for (var i = 0; i < this._widgetSurroundings.length; i++)
				{
					this._widgetContainer.appendChild(this._widgetSurroundings[i]);
				}
			}
		}
		else
		{
			this._widgetContainer = null;
			this._widgetPlaceholder = null;
		}

		this._surroundingsUpdated = false;

		return true;
	},

	update: function() {
		if (this._surroundingsUpdated)
		{
			var attached = this.widget ? this.widget.isAttached() : false;

			// Reattach the widget - this will call the "getDOMNode" function
			// and trigger the _rebuildContainer function.
			if (attached && this.widget)
			{
				this.widget.detachFromDOM();
				this.widget.attachToDOM();
			}
		}
	},

	getDOMNode: function(_widgetNode) {
		// Update the whole widgetContainer if this is not the first time this
		// function has been called but the widget node has changed.
		if (this._widgetNode != null && this._widgetNode != _widgetNode)
		{
			this._surroundingsUpdated = true;
		}

		// Copy a reference to the given node
		this._widgetNode = _widgetNode;

		// Build the container if it didn't exist yet.
		var updated = this._rebuildContainer();

		// Return the widget node itself if there are no surroundings arround
		// it
		if (this._widgetContainer == null)
		{
			return _widgetNode;
		}

		// Replace the widgetPlaceholder with the given widget node if the
		// widgetContainer has been updated
		if (updated)
		{
			this._widgetPlaceholder.parentNode.replaceChild(_widgetNode,
				this._widgetPlaceholder);
			if (!this._ownPlaceholder)
			{
				this._widgetPlaceholder = _widgetNode;
			}
		}

		// Return the widget container
		return this._widgetContainer;
	}

});

/**
 * The egw_action system requires an egwActionObjectInterface Interface implementation
 * to tie actions to DOM nodes.  This one can be used by any widget.
 *
 * The class extension is different than the widgets
 *
 */
function et2_action_object_impl(widget)
{
	var aoi = new egwActionObjectInterface();
	aoi.doGetDOMNode = function() {
		return widget.getDOMNode();
	};

// _outerCall may be used to determine, whether the state change has been
// evoked from the outside and the stateChangeCallback has to be called
// or not.
	aoi.doSetState = function(_state, _outerCall) {
	};

// The doTiggerEvent function may be overritten by the aoi if it wants to
// support certain action implementation specific events like EGW_AI_DRAG_OVER
// or EGW_AI_DRAG_OUT
	aoi.doTriggerEvent = function(_event, _data) {
		switch(_event)
		{
			case EGW_AI_DRAG_OVER:
				$j(this.node).addClass("ui-state-active");
				break;
			case EGW_AI_DRAG_OUT:
				$j(this.node).removeClass("ui-state-active");
				break;
		}
	};


	return aoi;
};