/**
 *	SortedObjectStore
 *	by Mattias Buelens
 *
 *	Hash table class to store objects, retrieve them by ID
 *	and loop through the IDs alphabetically.
 */

var SortedObjectStore = function() {
	var ObjById = {}, ObjAbc = [];

	return {
		/**
		 *	Get an object by its ID
		 */
		Get: function(Id) {
			return ObjById[Id.toLowerCase()];
		},
		/**
		 *	Get an object by its sorted index
		 */
		GetBySortIdx: function(Idx) {
			return ObjAbc[Idx];
		},
		/**
		 *	Get the amount of stored Objs
		 */
		GetCount: function() {
			return ObjAbc.length;
		},
		/**
		 *	Add an object to the store
		 */
		Add: function(Obj) {
			Obj.SortIdx = ObjAbc.length;
			// Store in the caches
			ObjById[Obj.Id.toLowerCase()] = ObjAbc[Obj.SortIdx] = Obj;
			// Update sorted cache
			UpdateAbc();
		},
		/**
		 *	Changes the ID of an object
		 */
		ChangeId: function(Obj, NewId) {
			// Remove from ID cache
			delete ObjById[Obj.Id.toLowerCase()];
			// Set new ID
			Obj.Id = NewId;
			// Store in ID cache
			ObjById[NewId.toLowerCase()] = Obj;
			// Update sorted cache
			UpdateAbc();
		},
		/**
		 *	Removes an object from the store
		 */
		Remove: function(Obj) {
			// Remove from caches
			delete ObjById[Obj.Id.toLowerCase()];
			ObjAbc.splice(Obj.SortIdx, 1);
			// Set sort index to -1
			Obj.SortIdx = -1;
			// Update sorted cache
			UpdateAbc();
		},
		/**
		 *	Removes all Objs from the store
		 */
		RemoveAll: function() {
			// Set all sort indexes to -1
			for(var i=0, len=ObjAbc.length, item; i<len; ++i) {
				item = ObjAbc[i];
				item.SortIdx = -1;
			}
			// Clear the caches
			ObjById = {};
			ObjAbc = [];
		}
	};

	function UpdateAbc() {
		// Sort alphabetically
		ObjAbc.sort(function(x, y) {
			var a = x.Id.toLowerCase(), b = y.Id.toLowerCase();
			return (a == b) ? 0 : (a > b) ? 1 : -1;
		});
		// Update the sort indexes
		for(var i=0, len=ObjAbc.length; i<len; ++i) {
			ObjAbc[i].SortIdx = i;
		}
	}
};