var HtmlTableImport = function(table){
	this.table = table; //hold Tabulator object
	this.fieldIndex = [];
	this.hasIndex = false;
};

HtmlTableImport.prototype.parseTable = function(){
	var self = this,
	element = self.table.element,
	options = self.table.options,
	columns = options.columns,
	headers = element.getElementsByTagName("th"),
	rows = element.getElementsByTagName("tbody")[0],
	data = [],
	newTable;

	self.hasIndex = false;

	self.table.options.htmlImporting.call(this.table);

	rows = rows ? rows.getElementsByTagName("tr") : [];

	//check for tablator inline options
	self._extractOptions(element, options);

	if(headers.length){
		self._extractHeaders(headers, rows);
	}else{
		self._generateBlankHeaders(headers, rows);
	}


	//iterate through table rows and build data set
	for(var index = 0; index < rows.length; index++){
		var row = rows[index],
		cells = row.getElementsByTagName("td"),
		item = {};

		//create index if the dont exist in table
		if(!self.hasIndex){
			item[options.index] = index;
		}

		for(var i = 0; i < cells.length; i++){
			var cell = cells[i];
			if(typeof this.fieldIndex[i] !== "undefined"){
				item[this.fieldIndex[i]] = cell.innerHTML;
			}
		}

		//add row data to item
		data.push(item);
	}

	//create new element
	var newElement = document.createElement("div");

	//transfer attributes to new element
	var attributes = element.attributes;

	// loop through attributes and apply them on div

	for(var i in attributes){
		if(typeof attributes[i] == "object"){
			newElement.setAttribute(attributes[i].name, attributes[i].value);
		}
	}

	// replace table with div element
	element.parentNode.replaceChild(newElement, element);

	options.data = data;

	self.table.options.htmlImported.call(this.table);

	// // newElement.tabulator(options);

	this.table.element = newElement;
};

//extract tabulator attribute options
HtmlTableImport.prototype._extractOptions = function(element, options, defaultOptions){
	var attributes = element.attributes;
	var optionsArr = defaultOptions ? Object.assign([], defaultOptions) : Object.keys(options);
	var optionsList = {};

	optionsArr.forEach(function(item){
		optionsList[item.toLowerCase()] = item;
	});

	for(var index in attributes){
		var attrib = attributes[index];
		var name;

		if(attrib && typeof attrib == "object" && attrib.name && attrib.name.indexOf("tabulator-") === 0){
			name = attrib.name.replace("tabulator-", "");

			if(typeof optionsList[name] !== "undefined"){
				options[optionsList[name]] = this._attribValue(attrib.value);
			}
		}
	}
};

//get value of attribute
HtmlTableImport.prototype._attribValue = function(value){
	if(value === "true"){
		return true;
	}

	if(value === "false"){
		return false;
	}

	return value;
};

//find column if it has already been defined
HtmlTableImport.prototype._findCol = function(title){
	var match = this.table.options.columns.find(function(column){
		return column.title === title;
	});

	return match || false;
};

//extract column from headers
HtmlTableImport.prototype._extractHeaders = function(headers, rows){
	for(var index = 0; index < headers.length; index++){
		var header = headers[index],
		exists = false,
		col = this._findCol(header.textContent),
		width, attributes;

		if(col){
			exists = true;
		}else{
			col = {title:header.textContent.trim()};
		}

		if(!col.field) {
			col.field = header.textContent.trim().toLowerCase().replace(" ", "_");
		}

		width = header.getAttribute("width");

		if(width && !col.width)	{
			col.width = width;
		}

		//check for tablator inline options
		attributes = header.attributes;

		// //check for tablator inline options
		this._extractOptions(header, col, Column.prototype.defaultOptionList);

		this.fieldIndex[index] = col.field;

		if(col.field == this.table.options.index){
			this.hasIndex = true;
		}

		if(!exists){
			this.table.options.columns.push(col);
		}

	}
};

//generate blank headers
HtmlTableImport.prototype._generateBlankHeaders = function(headers, rows){
	for(var index = 0; index < headers.length; index++){
		var header = headers[index],
		col = {title:"", field:"col" + index};

		this.fieldIndex[index] = col.field;

		var width = header.getAttribute("width");

		if(width){
			col.width = width;
		}

		this.table.options.columns.push(col);
	}
};

Tabulator.prototype.registerModule("htmlTableImport", HtmlTableImport);