;(function (){

"use strict";

var el = document.createElement('DIV');

if (Array.prototype.forEach) {
	var coreForEach = Array.prototype.forEach;
	var forEach = function(collection, fn) {
		coreForEach.call(collection, fn);
	};
}
else {
	var forEach = function(collection, fn) {
		for (var i = 0, len = collection.length; i < len; i++) {
			fn(collection[i], i);
		}
	};
}

if (el.getElementsByClassName === undefined) {
	var getElementsByClassName = function(parent, cls) {
		var elements = parent.getElementsByTagName('*');
		var match = [];
		for (var i = 0, leni = elements.length; i < leni; i++) {
			if (hasClass(elements[i], cls)) {
				match.push(elements[i]);
			}
		}
		return match;
	};
}
else {
	var getElementsByClassName = function(parent, cls) {
		return parent.getElementsByClassName(cls);
	};
}

var getElementsByTagName = function(parent, tag) {
	return parent.getElementsByTagName(tag);
};

var _ = {
	forEach: forEach,
	cls: getElementsByClassName,
	tag: getElementsByTagName,
	id: function(id) { return document.getElementById(id); }
};

var Signal = function() {
	var self = this;
	this.listeners = [];

	this.connect = function(callback) {
		if (callback === undefined) {
			wtf();
		}
		self.listeners.push(callback);
	};

	this.disconnect = function(callback) {
		if (callback === undefined) {
			self.listeners = [];
			return;
		}

		var pos = self.listeners.indexOf(callback);
		if (pos === -1) {
			console.log('Not connected', callback);
			return;
		}
		self.listeners.splice(pos, 1);
	};

	this.send = function() {
		var sendArguments = arguments;
		_.forEach(self.listeners, function(listener) {
			listener.apply(this, sendArguments);
		});
	};
};

var E = (function () {
	var P = function(name, value) {
		var name = name.split('=');
		this.name = name[0];
		this.propname = name[1];
		this.value = value;
	};

	return function(name, propname, value) {
		return new P(name, propname, value);
	}
}());

var Etree = (function () {
	var getText = function(node) {
		return node.textContent;
	};
	var setText = function(node, value) {
		node.textContent = value;
	};
	var getHTML = function(node) {
		return node.innerHTML;
	};
	var setHTML = function(node, value) {
		node.innerHTML = value;
	};
	var getAttribute = function(node, attribute) {
		return node.getAttribute(attribute);
	};
	var setAttribute = function(node, attribute, value) {
		node.setAttribute(attribute, value);
	};
	var setData = function(self, data) {
		for (var key in data) {
			if (_.has(data, key) && _.has(self.set, key)) {
				self.set[key](data[key]);
			}
		}
	};

	return function(root, initialData) {
		var getters = {};
		var setters = {};
		var elements = {};
		var elementNumber = 0;

		var valueAccessors = {};

		var buildElement = function(nodeData, parent) {
			if (nodeData.name === '#text') {
				var node = document.createTextNode(nodeData.value);
				if (nodeData.propname !== undefined) {
					valueAccessors[nodeData.propname] = [elementNumber, getText, setText];
				}
				elementNumber++;
				parent.appendChild(node);
			}
			else if (nodeData.name[0] === '@') {
				var attribute = nodeData.name.substr(1)
				parent.setAttribute(attribute, nodeData.value);
				if (nodeData.propname !== undefined) {
					valueAccessors[nodeData.propname] = [elementNumber - 1, function(node) { return getAttribute(node, attribute); }, function(node, value) { return setAttribute(node, attribute, value); }];
				}
			}
			else {
				var node = document.createElement(nodeData.name);
				if (nodeData.propname !== undefined) {
					valueAccessors[nodeData.propname] = [elementNumber, getHTML, setHTML];
				}

				elementNumber++;

				if (nodeData.value) {
					_.forEach(nodeData.value, function(subElement) {
						buildElement(subElement, node)
					});
				}

				if (parent) {
					parent.appendChild(node);
				}

				return node;
			}
		};

		if (root.cache) {
			var tree = root.cache.tree.cloneNode(true);
			var valueAccessors = root.cache.accessors;
		}
		else {
			var tree = buildElement(root);
			root.cache = root.cache || {};
			root.cache.tree = tree.cloneNode(true);
			root.cache.accessors = valueAccessors;
		}

		var flatNodesList = [];
		var flatNodes = function(root) {
			flatNodesList.push(root);
			if (root.childNodes) {
				_.forEach(root.childNodes, flatNodes);
			}
		};
		flatNodes(tree);

		for (var propname in valueAccessors) {
			var accessors = valueAccessors[propname];
			(function (accessors) {
				var node = flatNodesList[accessors[0]];
				getters[propname] = function() { return accessors[1](node); }
				setters[propname] = function(value) { return accessors[2](node, value); }
				elements[propname] = node;
			}(accessors));
		}

		var component = {
			tree: tree,
			get: getters,
			set: setters,
			elements: elements
		};
		component.setData = function(data) { setData(component, data); };
		if (initialData !== undefined) {
			component.setData(initialData);
		}
		return component;
	}
}());

var ModelInstance = function(context) {
	var self = this;

	this.context = context;

	this.signals = {
		changed: new Signal()
	};

	this.updateContext = function(context) {
		self.context = context;
		this.signals.changed.send(self);
	};
};


var ListModel = function() {
	var self = this;

	this.list = [];

	this.signals = {
		inserted: new Signal(),
		removed: new Signal()
	};

	this.insert = function(instance, position) {
		self.list.splice(position, 0, instance);
		self.signals.inserted.send({
			position: position,
			instance: instance,
			moved: false
		});
	};

	this.move = function(positionFrom, positionTo) {
		var moved = {from: positionFrom, to: positionTo};
		var instance = self.list[positionFrom];

		self.list.splice(positionFrom, 1);
		self.signals.removed.send({
			position: positionFrom,
			instance: instance,
			moved: moved
		});
		self.list.splice(positionTo, 0, instance);
		self.signals.inserted.send({
			position: positionTo,
			instance: instance,
			moved: moved
		});
	};

	this.remove = function(position) {
		var instance = self.list[position];
		self.list.splice(position, 1);
		self.signals.removed.send({position: position, instance: instance, moved: false});
	};

	this.indexOf = function(instance) {
		return self.list.indexOf(instance);
	};

	this.has = function(instance) {
		return self.list.indexOf(instance) !== -1;
	};
};


var SortedListModel = function(compareFunction) {
	var self = this;

	var model = new ListModel();

	this.list = model.list;

	this.signals = {
		inserted: model.signals.inserted,
		removed: model.signals.removed
	};

	this.insert = function(instance) {
		var position = self.findPosition(instance);
		model.insert(instance, position);
		instance.signals.changed.connect(self.moveSortedInstance);
	};

	this.remove= function(instance) {
		if (!model.has(instance)) {
			return;
		}
		model.remove(model.indexOf(instance));
		instance.signals.changed.disconnect(self.moveSortedInstance);
	};

	this.findPosition = function(instance) {
		for (var i = 0, leni = self.list.length; i < leni; i++) {
			if (compareFunction(self.list[i], instance) > 0) {
				return i;
			}
		}
		return self.list.length;
	};

	this.moveSortedPosition = function(position) {
		var instance = self.list[position];
		self.list.splice(position, 1);
		var targetPosition = self.findPosition(instance);
		self.list.splice(position, 0, instance);
		if (position !== targetPosition) {
			model.move(position, targetPosition);
		}
	};

	this.moveSortedInstance = function(instance) {
		self.moveSortedPosition(model.indexOf(instance));
	};

	this.indexOf = function(instance) {
		return model.indexOf(instance);
	};

	this.has = function(instance) {
		return self.list.indexOf(instance) !== -1;
	};
};


var AutoListModel = function(options) {
	var self = this;

	var diffAdded = function(item, index) {
		self.model.insert(item, index);
	};

	var diffDeleted = function(item, index) {
		self.model.remove(index);
	};

	var diffMoved = function(pos_from, pos_to) {
		self.model.move(pos_from, pos_to);
	};

	var o = {
		added: diffAdded,
		deleted: diffDeleted,
		moved: diffMoved
	};

	for (var k in options) {
		if (!k in o) {
			o[k] = options[k];
		}
		else {
			var old = o[k];
			var custom = options[k];
			(function (old, custom) {
				o[k] = function() {
					custom.apply(null, arguments);
					old.apply(self, arguments);
				}
			}(old, custom));
		}
	}

	if (!_.has(o, 'getId')) {
		if (o.wrapModel) {
			o.getId = function(item) { return item.context.id; };
		}
		else {
			o.getId = function(item) { return item.id; };
		}
	}

	if (o.wrapModel) {
		o.applyChanges = function(oldList, newList) {
			for (var i = 0, leni = oldList.length; i < leni; i++) {
				var oldInstance = oldList[i];
				var newInstance = newList[i];
				if (!_.isEqual(oldInstance.context, newInstance.context)) {
					oldInstance.updateContext(newInstance.context);
				}
			}
		};
	}

	this.model = new ListModel();
	this.differ = new ListDiffer(o);
	this.list = this.model.list;

	this.setList = function(list) {
		var wrappedList = list;
		if (o.wrapModel) {
			wrappedList = [];
			_.forEach(list, function(item) {
				wrappedList.push(new ModelInstance(item));
			});
		}
		self.differ.setList(wrappedList);
	};

	this.signals = {
		inserted: this.model.signals.inserted,
		removed: this.model.signals.removed
	};
};


var ListView = function(element, model, widget) {
	var self = this;

	var instances = [];
	var widgets = [];
	var movingWidget = undefined;

	this.destroy = function() {
		model.signals.inserted.disconnect(self.insert);
		model.signals.removed.disconnect(self.remove);
		while (instances.length) {
			self.remove({position: 0});
		}
	};

	this.insert = function(data) {
		var append = data.position === instances.length;
		instances.splice(data.position, 0, data.instance);
		if (movingWidget === undefined) {
			var widgetInstance = new widget();
			widgetInstance.modelInstance = model;
		}
		else {
			var widgetInstance = movingWidget;
			movingWidget = undefined;
		}
		if (!append) {
			var old = widgets[data.position];
		}
		if (!data.move) {
			widgetInstance.construct(data.instance);
		}
		widgets.splice(data.position, 0, widgetInstance);
		if (append) {
			element.appendChild(widgetInstance.component.tree);
		}
		else {
			element.insertBefore(widgetInstance.component.tree, old.component.tree);
		}
	};

	this.remove = function(data) {
		instances.splice(data.position, 1);
		var widgetInstance = widgets[data.position];
		if (widgetInstance.component.tree.parentNode) {
			widgetInstance.component.tree.parentNode.removeChild(widgetInstance.component.tree);
		}
		if (data.move) {
			movingWidget = widgetInstance;
		}
		else {
			widgetInstance.destroy();
		}
		widgets.splice(data.position, 1);
	}

	_.forEach(model.list, function(data) {
		self.insert({
			position: instances.length,
			instance: data,
			move: false
		});
	});

	model.signals.inserted.connect(this.insert);
	model.signals.removed.connect(this.remove);
};



var dummyFunction = function() {};

var Widget = function(options) {
	return function () {
		var self = this;

		var constructWidget = dummyFunction;
		var destroyWidget = dummyFunction;
		var updateWidget = dummyFunction;

		this.options = options;
		this.template = options.template;
		this.component = undefined;
		this.data = undefined;
		this.modelInstance = undefined;

		if (options.construct !== undefined) {
			constructWidget = options.construct.bind(this);
		}
		if (options.destroy !== undefined) {
			destroyWidget = options.destroy.bind(this);
		}
		if (options.update !== undefined) {
			updateWidget = options.update.bind(this);
		}

		this.construct = function(data) {
			self.component = Etree(self.template);
			if (data === undefined) {
				self.data = {};
			}
			else {
				self.update(data);
			}
			if (self.data.signals !== undefined) {
				data.signals.changed.connect(self.update);
			}
			constructWidget(data);
			return self.component;
		};

		this.destroy = function() {
			destroyWidget();
			if (self.data.signals !== undefined) {
				self.data.signals.changed.disconnect(self.update);
			}
			self.data = undefined;
			self.component = undefined
			self.modelInstance = undefined;
		};

		this.update = function(data) {
			updateWidget(data);
			self.data = data;
		};
	};
};

var ListDiffer = function(options) {
	var o = {
		initial: [],
		added: function() {},
		deleted: function() {},
		moved: function() {},
		applyChanges: function(oldList, newList) { oldList = newList; },
		getId: function(item) { return item.id; }
	};
	for (var k in options) { if (options.hasOwnProperty(k)) o[k] = options[k]; }

	var list = o.initial;
	var added = o.added;
	var deleted = o.deleted;
	var moved = o.moved;
	var applyChanges = o.applyChanges;
	var getId = o.getId;

	this.setList = function(newList) {
		var currentDict = {};
		var newDict = {};

		_.forEach(list, function(item) {
			currentDict[getId(item)] = item;
		});
		_.forEach(newList, function(item) {
			newDict[getId(item)] = item;
		});

		var toCreate = [];
		var toDelete = [];

		_.forEach(newList, function(item) {
			var id = getId(item);
			if (!_.has(currentDict, id)) {
				toCreate.push(id);
			}
		});
		_.forEach(list, function(item) {
			var id = getId(item);
			if (!_.has(newDict, id)) {
				toDelete.push(id);
			}
		});
		toDelete.reverse();

		var indexList = [];
		_.forEach(list, function(item) {
			indexList.push(getId(item));
		});

		_.forEach(toDelete, function(id) {
			var index = indexList.indexOf(id);
			var item = list[index];
			indexList.splice(index, 1);
			list.splice(index, 1);
			deleted(item, index);
		});

		_.forEach(toCreate, function(id) {
			var item = newDict[id];
			var index = list.length;
			indexList.push(id);
			list.push(item);
			added(item, index);
		});

		for (var i = 0, leni = newList.length; i < leni; i++) {
			var newId = getId(newList[i]);
			if (newId !== indexList[i]) {
				var oldIndex = indexList.indexOf(newId);
				var listItem = list.splice(oldIndex, 1)[0];
				list.splice(i, 0, listItem);
				listItem = indexList.splice(oldIndex, 1)[0];
				indexList.splice(i, 0, listItem);
				moved(oldIndex, i);
			}
		}

		applyChanges(list, newList);
	};
};



window.Reactor = {
	Signal: Signal,
	E: E,
	Etree: Etree,
	//EtreeHighlight: EtreeHighlight,
	ModelInstance: ModelInstance,
	ListModel: ListModel,
	SortedListModel: SortedListModel,
	AutoListModel: AutoListModel,
	ListView: ListView,
	Widget: Widget,
	ListDiffer: ListDiffer,
	utils: _
};

}());