function noop() {}

function assign(target) {
	var k,
		source,
		i = 1,
		len = arguments.length;
	for (; i < len; i++) {
		source = arguments[i];
		for (k in source) target[k] = source[k];
	}

	return target;
}

function appendNode(node, target) {
	target.appendChild(node);
}

function insertNode(node, target, anchor) {
	target.insertBefore(node, anchor);
}

function detachNode(node) {
	node.parentNode.removeChild(node);
}

function detachAfter(before) {
	while (before.nextSibling) {
		before.parentNode.removeChild(before.nextSibling);
	}
}

// TODO this is out of date
function destroyEach(iterations, detach, start) {
	for (var i = start; i < iterations.length; i += 1) {
		if (iterations[i]) iterations[i].destroy(detach);
	}
}

function createElement(name) {
	return document.createElement(name);
}

function createText(data) {
	return document.createTextNode(data);
}

function blankObject() {
	return Object.create(null);
}

function destroy(detach) {
	this.destroy = noop;
	this.fire('destroy');
	this.set = this.get = noop;

	if (detach !== false) this._fragment.unmount();
	this._fragment.destroy();
	this._fragment = this._state = null;
}

function differs(a, b) {
	return a !== b || ((a && typeof a === 'object') || typeof a === 'function');
}

function dispatchObservers(component, group, changed, newState, oldState) {
	for (var key in group) {
		if (!changed[key]) continue;

		var newValue = newState[key];
		var oldValue = oldState[key];

		var callbacks = group[key];
		if (!callbacks) continue;

		for (var i = 0; i < callbacks.length; i += 1) {
			var callback = callbacks[i];
			if (callback.__calling) continue;

			callback.__calling = true;
			callback.call(component, newValue, oldValue);
			callback.__calling = false;
		}
	}
}

function fire(eventName, data) {
	var handlers =
		eventName in this._handlers && this._handlers[eventName].slice();
	if (!handlers) return;

	for (var i = 0; i < handlers.length; i += 1) {
		handlers[i].call(this, data);
	}
}

function get(key) {
	return key ? this._state[key] : this._state;
}

function init(component, options) {
	component.options = options;

	component._observers = { pre: blankObject(), post: blankObject() };
	component._handlers = blankObject();
	component._root = options._root || component;
	component._yield = options._yield;
	component._bind = options._bind;
}

function observe(key, callback, options) {
	var group = options && options.defer
		? this._observers.post
		: this._observers.pre;

	(group[key] || (group[key] = [])).push(callback);

	if (!options || options.init !== false) {
		callback.__calling = true;
		callback.call(this, this._state[key]);
		callback.__calling = false;
	}

	return {
		cancel: function() {
			var index = group[key].indexOf(callback);
			if (~index) group[key].splice(index, 1);
		}
	};
}

function on(eventName, handler) {
	if (eventName === 'teardown') return this.on('destroy', handler);

	var handlers = this._handlers[eventName] || (this._handlers[eventName] = []);
	handlers.push(handler);

	return {
		cancel: function() {
			var index = handlers.indexOf(handler);
			if (~index) handlers.splice(index, 1);
		}
	};
}

function set(newState) {
	this._set(assign({}, newState));
	if (this._root._lock) return;
	this._root._lock = true;
	callAll(this._root._beforecreate);
	callAll(this._root._oncreate);
	callAll(this._root._aftercreate);
	this._root._lock = false;
}

function _set(newState) {
	var oldState = this._state,
		changed = {},
		dirty = false;

	for (var key in newState) {
		if (differs(newState[key], oldState[key])) changed[key] = dirty = true;
	}
	if (!dirty) return;

	this._state = assign({}, oldState, newState);
	this._recompute(changed, this._state);
	if (this._bind) this._bind(changed, this._state);
	dispatchObservers(this, this._observers.pre, changed, this._state, oldState);
	this._fragment.update(changed, this._state);
	dispatchObservers(this, this._observers.post, changed, this._state, oldState);
}

function callAll(fns) {
	while (fns && fns.length) fns.pop()();
}

function _mount(target, anchor) {
	this._fragment.mount(target, anchor);
}

function _unmount() {
	this._fragment.unmount();
}

var proto = {
	destroy: destroy,
	get: get,
	fire: fire,
	observe: observe,
	on: on,
	set: set,
	teardown: destroy,
	_recompute: noop,
	_set: _set,
	_mount: _mount,
	_unmount: _unmount
};

/* generated by Svelte vX.Y.Z */

function create_main_fragment(state, component) {
	var text, p, text_1;

	var each_block_value = state.comments;

	var each_block_iterations = [];

	for (var i = 0; i < each_block_value.length; i += 1) {
		each_block_iterations[i] = create_each_block(state, each_block_value, each_block_value[i], i, component);
	}

	return {
		create: function() {
			for (var i = 0; i < each_block_iterations.length; i += 1) {
				each_block_iterations[i].create();
			}

			text = createText("\n\n");
			p = createElement("p");
			text_1 = createText(state.foo);
		},

		mount: function(target, anchor) {
			for (var i = 0; i < each_block_iterations.length; i += 1) {
				each_block_iterations[i].mount(target, anchor);
			}

			insertNode(text, target, anchor);
			insertNode(p, target, anchor);
			appendNode(text_1, p);
		},

		update: function(changed, state) {
			var each_block_value = state.comments;

			if (changed.comments || changed.elapsed || changed.time) {
				for (var i = 0; i < each_block_value.length; i += 1) {
					if (each_block_iterations[i]) {
						each_block_iterations[i].update(changed, state, each_block_value, each_block_value[i], i);
					} else {
						each_block_iterations[i] = create_each_block(state, each_block_value, each_block_value[i], i, component);
						each_block_iterations[i].create();
						each_block_iterations[i].mount(text.parentNode, text);
					}
				}

				for (; i < each_block_iterations.length; i += 1) {
					each_block_iterations[i].unmount();
					each_block_iterations[i].destroy();
				}
				each_block_iterations.length = each_block_value.length;
			}

			if (changed.foo) {
				text_1.data = state.foo;
			}
		},

		unmount: function() {
			for (var i = 0; i < each_block_iterations.length; i += 1) {
				each_block_iterations[i].unmount();
			}

			detachNode(text);
			detachNode(p);
		},

		destroy: function() {
			destroyEach(each_block_iterations, false, 0);
		}
	};
}

// (1:0) {{#each comments as comment, i}}
function create_each_block(state, each_block_value, comment, i, component) {
	var div, strong, text, text_1, span, text_2_value = comment.author, text_2, text_3, text_4_value = state.elapsed(comment.time, state.time), text_4, text_5, text_6, raw_value = comment.html, raw_before;

	return {
		create: function() {
			div = createElement("div");
			strong = createElement("strong");
			text = createText(i);
			text_1 = createText("\n\n\t\t");
			span = createElement("span");
			text_2 = createText(text_2_value);
			text_3 = createText(" wrote ");
			text_4 = createText(text_4_value);
			text_5 = createText(" ago:");
			text_6 = createText("\n\n\t\t");
			raw_before = createElement('noscript');
			this.hydrate();
		},

		hydrate: function() {
			div.className = "comment";
			span.className = "meta";
		},

		mount: function(target, anchor) {
			insertNode(div, target, anchor);
			appendNode(strong, div);
			appendNode(text, strong);
			appendNode(text_1, div);
			appendNode(span, div);
			appendNode(text_2, span);
			appendNode(text_3, span);
			appendNode(text_4, span);
			appendNode(text_5, span);
			appendNode(text_6, div);
			appendNode(raw_before, div);
			raw_before.insertAdjacentHTML("afterend", raw_value);
		},

		update: function(changed, state, each_block_value, comment, i) {
			if ((changed.comments) && text_2_value !== (text_2_value = comment.author)) {
				text_2.data = text_2_value;
			}

			if ((changed.elapsed || changed.comments || changed.time) && text_4_value !== (text_4_value = state.elapsed(comment.time, state.time))) {
				text_4.data = text_4_value;
			}

			if ((changed.comments) && raw_value !== (raw_value = comment.html)) {
				detachAfter(raw_before);
				raw_before.insertAdjacentHTML("afterend", raw_value);
			}
		},

		unmount: function() {
			detachAfter(raw_before);

			detachNode(div);
		},

		destroy: noop
	};
}

function SvelteComponent(options) {
	init(this, options);
	this._state = options.data || {};

	this._fragment = create_main_fragment(this._state, this);

	if (options.target) {
		this._fragment.create();
		this._fragment.mount(options.target, options.anchor || null);
	}
}

assign(SvelteComponent.prototype, proto);

export default SvelteComponent;