var core = require('./core');
var EpubCFI = require('./epubcfi');
var Hook = require('./hook');
var Url = require('./core').Url;

function Section(item, hooks){
		this.idref = item.idref;
		this.linear = item.linear;
		this.properties = item.properties;
		this.index = item.index;
		this.href = item.href;
		this.url = item.url;
		this.next = item.next;
		this.prev = item.prev;

		this.cfiBase = item.cfiBase;

		if (hooks) {
			this.hooks = hooks;
		} else {
			this.hooks = {};
			this.hooks.serialize = new Hook(this);
			this.hooks.content = new Hook(this);
		}

};


Section.prototype.load = function(_request){
	var request = _request || this.request || require('./request');
	var loading = new core.defer();
	var loaded = loading.promise;

	if(this.contents) {
		loading.resolve(this.contents);
	} else {
		request(this.url)
			.then(function(xml){
				var base;
				var directory = new Url(this.url).directory;

				this.document = xml;
				this.contents = xml.documentElement;

				return this.hooks.content.trigger(this.document, this);
			}.bind(this))
			.then(function(){
				loading.resolve(this.contents);
			}.bind(this))
			.catch(function(error){
				loading.reject(error);
			});
	}

	return loaded;
};

Section.prototype.base = function(_document){
		var task = new core.defer();
		var base = _document.createElement("base"); // TODO: check if exists
		var head;

		base.setAttribute("href", window.location.origin + "/" +this.url);

		if(_document) {
			head = _document.querySelector("head");
		}
		if(head) {
			head.insertBefore(base, head.firstChild);
			task.resolve();
		} else {
			task.reject(new Error("No head to insert into"));
		}


		return task.promise;
};

Section.prototype.beforeSectionLoad = function(){
	// Stub for a hook - replace me for now
};

Section.prototype.render = function(_request){
	var rendering = new core.defer();
	var rendered = rendering.promise;
	this.output; // TODO: better way to return this from hooks?

	this.load(_request).
		then(function(contents){
			var serializer;

			if (typeof XMLSerializer === "undefined") {
				XMLSerializer = require('xmldom').XMLSerializer;
			}
			serializer = new XMLSerializer();
			this.output = serializer.serializeToString(contents);
			return this.output;
		}.bind(this)).
		then(function(){
			return this.hooks.serialize.trigger(this.output, this);
		}.bind(this)).
		then(function(){
			rendering.resolve(this.output);
		}.bind(this))
		.catch(function(error){
			rendering.reject(error);
		});

	return rendered;
};

Section.prototype.find = function(_query){

};

/*
* Reconciles the current chapters layout properies with
* the global layout properities.
* Takes: global layout settings object, chapter properties string
* Returns: Object with layout properties
*/
Section.prototype.reconcileLayoutSettings = function(global){
	//-- Get the global defaults
	var settings = {
		layout : global.layout,
		spread : global.spread,
		orientation : global.orientation
	};

	//-- Get the chapter's display type
	this.properties.forEach(function(prop){
		var rendition = prop.replace("rendition:", '');
		var split = rendition.indexOf("-");
		var property, value;

		if(split != -1){
			property = rendition.slice(0, split);
			value = rendition.slice(split+1);

			settings[property] = value;
		}
	});
 return settings;
};

Section.prototype.cfiFromRange = function(_range) {
	return new EpubCFI(_range, this.cfiBase).toString();
};

Section.prototype.cfiFromElement = function(el) {
	return new EpubCFI(el, this.cfiBase).toString();
};

module.exports = Section;