/**
 * @license Highcharts JS v4.1.5 (2015-04-13)
 * Data module
 *
 * (c) 2012-2014 Torstein Honsi
 *
 * License: www.highcharts.com/license
 */

// JSLint options:
/*global jQuery, HighchartsAdapter */

(function (Highcharts) {
	
	// Utilities
	var each = Highcharts.each,
		pick = Highcharts.pick,
		inArray = HighchartsAdapter.inArray,
		splat = Highcharts.splat,
		SeriesBuilder;
	
	
	// The Data constructor
	var Data = function (dataOptions, chartOptions) {
		this.init(dataOptions, chartOptions);
	};
	
	// Set the prototype properties
	Highcharts.extend(Data.prototype, {
		
	/**
	 * Initialize the Data object with the given options
	 */
	init: function (options, chartOptions) {
		this.options = options;
		this.chartOptions = chartOptions;
		this.columns = options.columns || this.rowsToColumns(options.rows) || [];
		this.firstRowAsNames = pick(options.firstRowAsNames, true);
		this.decimalRegex = options.decimalPoint && new RegExp('^([0-9]+)' + options.decimalPoint + '([0-9]+)$');

		// This is a two-dimensional array holding the raw, trimmed string values
		// with the same organisation as the columns array. It makes it possible
		// for example to revert from interpreted timestamps to string-based
		// categories.
		this.rawColumns = [];

		// No need to parse or interpret anything
		if (this.columns.length) {
			this.dataFound();

		// Parse and interpret
		} else {

			// Parse a CSV string if options.csv is given
			this.parseCSV();
			
			// Parse a HTML table if options.table is given
			this.parseTable();

			// Parse a Google Spreadsheet 
			this.parseGoogleSpreadsheet();	
		}

	},

	/**
	 * Get the column distribution. For example, a line series takes a single column for 
	 * Y values. A range series takes two columns for low and high values respectively,
	 * and an OHLC series takes four columns.
	 */
	getColumnDistribution: function () {
		var chartOptions = this.chartOptions,
			options = this.options,
			xColumns = [],
			getValueCount = function (type) {
				return (Highcharts.seriesTypes[type || 'line'].prototype.pointArrayMap || [0]).length;
			},
			getPointArrayMap = function (type) {
				return Highcharts.seriesTypes[type || 'line'].prototype.pointArrayMap;
			},
			globalType = chartOptions && chartOptions.chart && chartOptions.chart.type,
			individualCounts = [],
			seriesBuilders = [],
			seriesIndex = 0,
			i;

		each((chartOptions && chartOptions.series) || [], function (series) {
			individualCounts.push(getValueCount(series.type || globalType));
		});

		// Collect the x-column indexes from seriesMapping
		each((options && options.seriesMapping) || [], function (mapping) {
			xColumns.push(mapping.x || 0);
		});

		// If there are no defined series with x-columns, use the first column as x column
		if (xColumns.length === 0) {
			xColumns.push(0);
		}

		// Loop all seriesMappings and constructs SeriesBuilders from
		// the mapping options.
		each((options && options.seriesMapping) || [], function (mapping) {
			var builder = new SeriesBuilder(),
				name,
				numberOfValueColumnsNeeded = individualCounts[seriesIndex] || getValueCount(globalType),
				seriesArr = (chartOptions && chartOptions.series) || [],
				series = seriesArr[seriesIndex] || {},
				pointArrayMap = getPointArrayMap(series.type || globalType) || ['y'];

			// Add an x reader from the x property or from an undefined column
			// if the property is not set. It will then be auto populated later.
			builder.addColumnReader(mapping.x, 'x');

			// Add all column mappings
			for (name in mapping) {
				if (mapping.hasOwnProperty(name) && name !== 'x') {
					builder.addColumnReader(mapping[name], name);
				}
			}

			// Add missing columns
			for (i = 0; i < numberOfValueColumnsNeeded; i++) {
				if (!builder.hasReader(pointArrayMap[i])) {
					//builder.addNextColumnReader(pointArrayMap[i]);
					// Create and add a column reader for the next free column index
					builder.addColumnReader(undefined, pointArrayMap[i]);
				}
			}

			seriesBuilders.push(builder);
			seriesIndex++;
		});

		var globalPointArrayMap = getPointArrayMap(globalType);
		if (globalPointArrayMap === undefined) {
			globalPointArrayMap = ['y'];
		}

		this.valueCount = {
			global: getValueCount(globalType),
			xColumns: xColumns,
			individual: individualCounts,
			seriesBuilders: seriesBuilders,
			globalPointArrayMap: globalPointArrayMap
		};
	},

	/**
	 * When the data is parsed into columns, either by CSV, table, GS or direct input,
	 * continue with other operations.
	 */
	dataFound: function () {
		
		if (this.options.switchRowsAndColumns) {
			this.columns = this.rowsToColumns(this.columns);
		}

		// Interpret the info about series and columns
		this.getColumnDistribution();

		// Interpret the values into right types
		this.parseTypes();
		
		// Handle columns if a handleColumns callback is given
		if (this.parsed() !== false) {
		
			// Complete if a complete callback is given
			this.complete();
		}
		
	},
	
	/**
	 * Parse a CSV input string
	 */
	parseCSV: function () {
		var self = this,
			options = this.options,
			csv = options.csv,
			columns = this.columns,
			startRow = options.startRow || 0,
			endRow = options.endRow || Number.MAX_VALUE,
			startColumn = options.startColumn || 0,
			endColumn = options.endColumn || Number.MAX_VALUE,
			itemDelimiter,
			lines,
			activeRowNo = 0;
			
		if (csv) {
			
			lines = csv
				.replace(/\r\n/g, "\n") // Unix
				.replace(/\r/g, "\n") // Mac
				.split(options.lineDelimiter || "\n");

			itemDelimiter = options.itemDelimiter || (csv.indexOf('\t') !== -1 ? '\t' : ',');
			
			each(lines, function (line, rowNo) {
				var trimmed = self.trim(line),
					isComment = trimmed.indexOf('#') === 0,
					isBlank = trimmed === '',
					items;
				
				if (rowNo >= startRow && rowNo <= endRow && !isComment && !isBlank) {
					items = line.split(itemDelimiter);
					each(items, function (item, colNo) {
						if (colNo >= startColumn && colNo <= endColumn) {
							if (!columns[colNo - startColumn]) {
								columns[colNo - startColumn] = [];					
							}
							
							columns[colNo - startColumn][activeRowNo] = item;
						}
					});
					activeRowNo += 1;
				}
			});

			this.dataFound();
		}
	},
	
	/**
	 * Parse a HTML table
	 */
	parseTable: function () {
		var options = this.options,
			table = options.table,
			columns = this.columns,
			startRow = options.startRow || 0,
			endRow = options.endRow || Number.MAX_VALUE,
			startColumn = options.startColumn || 0,
			endColumn = options.endColumn || Number.MAX_VALUE;

		if (table) {
			
			if (typeof table === 'string') {
				table = document.getElementById(table);
			}
			
			each(table.getElementsByTagName('tr'), function (tr, rowNo) {
				if (rowNo >= startRow && rowNo <= endRow) {
					each(tr.children, function (item, colNo) {
						if ((item.tagName === 'TD' || item.tagName === 'TH') && colNo >= startColumn && colNo <= endColumn) {
							if (!columns[colNo - startColumn]) {
								columns[colNo - startColumn] = [];					
							}
							
							columns[colNo - startColumn][rowNo - startRow] = item.innerHTML;
						}
					});
				}
			});

			this.dataFound(); // continue
		}
	},

	/**
	 */
	parseGoogleSpreadsheet: function () {
		var self = this,
			options = this.options,
			googleSpreadsheetKey = options.googleSpreadsheetKey,
			columns = this.columns,
			startRow = options.startRow || 0,
			endRow = options.endRow || Number.MAX_VALUE,
			startColumn = options.startColumn || 0,
			endColumn = options.endColumn || Number.MAX_VALUE,
			gr, // google row
			gc; // google column

		if (googleSpreadsheetKey) {
			jQuery.ajax({
				dataType: 'json', 
				url: 'https://spreadsheets.google.com/feeds/cells/' + 
				  googleSpreadsheetKey + '/' + (options.googleSpreadsheetWorksheet || 'od6') +
					  '/public/values?alt=json-in-script&callback=?',
				error: options.error,
				success: function (json) {
					// Prepare the data from the spreadsheat
					var cells = json.feed.entry,
						cell,
						cellCount = cells.length,
						colCount = 0,
						rowCount = 0,
						i;
				
					// First, find the total number of columns and rows that 
					// are actually filled with data
					for (i = 0; i < cellCount; i++) {
						cell = cells[i];
						colCount = Math.max(colCount, cell.gs$cell.col);
						rowCount = Math.max(rowCount, cell.gs$cell.row);			
					}
				
					// Set up arrays containing the column data
					for (i = 0; i < colCount; i++) {
						if (i >= startColumn && i <= endColumn) {
							// Create new columns with the length of either end-start or rowCount
							columns[i - startColumn] = [];

							// Setting the length to avoid jslint warning
							columns[i - startColumn].length = Math.min(rowCount, endRow - startRow);
						}
					}
					
					// Loop over the cells and assign the value to the right
					// place in the column arrays
					for (i = 0; i < cellCount; i++) {
						cell = cells[i];
						gr = cell.gs$cell.row - 1; // rows start at 1
						gc = cell.gs$cell.col - 1; // columns start at 1

						// If both row and col falls inside start and end
						// set the transposed cell value in the newly created columns
						if (gc >= startColumn && gc <= endColumn &&
							gr >= startRow && gr <= endRow) {
							columns[gc - startColumn][gr - startRow] = cell.content.$t;
						}
					}
					self.dataFound();
				}
			});
		}
	},
	
	/**
	 * Trim a string from whitespace
	 */
	trim: function (str, inside) {
		if (typeof str === 'string') {
			str = str.replace(/^\s+|\s+$/g, '');

			// Clear white space insdie the string, like thousands separators
			if (inside && /^[0-9\s]+$/.test(str)) { 
				str = str.replace(/\s/g, '');
			}

			if (this.decimalRegex) {
				str = str.replace(this.decimalRegex, '$1.$2');
			}
		}
		return str;
	},
	
	/**
	 * Parse numeric cells in to number types and date types in to true dates.
	 */
	parseTypes: function () {
		var columns = this.columns,
			col = columns.length;

		while (col--) {
			this.parseColumn(columns[col], col);
		}

	},

	/**
	 * Parse a single column. Set properties like .isDatetime and .isNumeric.
	 */
	parseColumn: function (column, col) {
		var rawColumns = this.rawColumns,
			columns = this.columns, 
			row = column.length,
			val,
			floatVal,
			trimVal,
			trimInsideVal,
			firstRowAsNames = this.firstRowAsNames,
			isXColumn = inArray(col, this.valueCount.xColumns) !== -1,
			dateVal,
			backup = [],
			diff,
			chartOptions = this.chartOptions,
			descending,
			columnTypes = this.options.columnTypes || [],
			columnType = columnTypes[col],
			forceCategory = isXColumn && ((chartOptions && chartOptions.xAxis && splat(chartOptions.xAxis)[0].type === 'category') || columnType === 'string');
		
		if (!rawColumns[col]) {
			rawColumns[col] = [];
		}
		while (row--) {
			val = backup[row] || column[row];
			
			trimVal = this.trim(val);
			trimInsideVal = this.trim(val, true);
			floatVal = parseFloat(trimInsideVal);

			// Set it the first time
			if (rawColumns[col][row] === undefined) {
				rawColumns[col][row] = trimVal;
			}
			
			// Disable number or date parsing by setting the X axis type to category
			if (forceCategory || (row === 0 && firstRowAsNames)) {
				column[row] = trimVal;

			} else if (+trimInsideVal === floatVal) { // is numeric
			
				column[row] = floatVal;
				
				// If the number is greater than milliseconds in a year, assume datetime
				if (floatVal > 365 * 24 * 3600 * 1000 && columnType !== 'float') {
					column.isDatetime = true;
				} else {
					column.isNumeric = true;
				}

				if (column[row + 1] !== undefined) {
					descending = floatVal > column[row + 1];
				}
			
			// String, continue to determine if it is a date string or really a string
			} else {
				dateVal = this.parseDate(val);
				// Only allow parsing of dates if this column is an x-column
				if (isXColumn && typeof dateVal === 'number' && !isNaN(dateVal) && columnType !== 'float') { // is date
					backup[row] = val; 
					column[row] = dateVal;
					column.isDatetime = true;

					// Check if the dates are uniformly descending or ascending. If they 
					// are not, chances are that they are a different time format, so check
					// for alternative.
					if (column[row + 1] !== undefined) {
						diff = dateVal > column[row + 1];
						if (diff !== descending && descending !== undefined) {
							if (this.alternativeFormat) {
								this.dateFormat = this.alternativeFormat;
								row = column.length;
								this.alternativeFormat = this.dateFormats[this.dateFormat].alternative;
							} else {
								column.unsorted = true;
							}
						}
						descending = diff;
					}
				
				} else { // string
					column[row] = trimVal === '' ? null : trimVal;
					if (row !== 0 && (column.isDatetime || column.isNumeric)) {
						column.mixed = true;
					}
				}
			}
		}

		// If strings are intermixed with numbers or dates in a parsed column, it is an indication
		// that parsing went wrong or the data was not intended to display as numbers or dates and 
		// parsing is too aggressive. Fall back to categories. Demonstrated in the 
		// highcharts/demo/column-drilldown sample.
		if (isXColumn && column.mixed) {
			columns[col] = rawColumns[col];
		}

		// If the 0 column is date or number and descending, reverse all columns. 
		if (isXColumn && descending && this.options.sort) {
			for (col = 0; col < columns.length; col++) {
				columns[col].reverse();
				if (firstRowAsNames) {
					columns[col].unshift(columns[col].pop());
				}
			}
		}
	},
	
	/**
	 * A collection of available date formats, extendable from the outside to support
	 * custom date formats.
	 */
	dateFormats: {
		'YYYY-mm-dd': {
			regex: /^([0-9]{4})[\-\/\.]([0-9]{2})[\-\/\.]([0-9]{2})$/,
			parser: function (match) {
				return Date.UTC(+match[1], match[2] - 1, +match[3]);
			}
		},
		'dd/mm/YYYY': {
			regex: /^([0-9]{1,2})[\-\/\.]([0-9]{1,2})[\-\/\.]([0-9]{4})$/,
			parser: function (match) {
				return Date.UTC(+match[3], match[2] - 1, +match[1]);
			},
			alternative: 'mm/dd/YYYY' // different format with the same regex
		},
		'mm/dd/YYYY': {
			regex: /^([0-9]{1,2})[\-\/\.]([0-9]{1,2})[\-\/\.]([0-9]{4})$/,
			parser: function (match) {
				return Date.UTC(+match[3], match[1] - 1, +match[2]);
			}
		},
		'dd/mm/YY': {
			regex: /^([0-9]{1,2})[\-\/\.]([0-9]{1,2})[\-\/\.]([0-9]{2})$/,
			parser: function (match) {
				return Date.UTC(+match[3] + 2000, match[2] - 1, +match[1]);
			},
			alternative: 'mm/dd/YY' // different format with the same regex
		},
		'mm/dd/YY': {
			regex: /^([0-9]{1,2})[\-\/\.]([0-9]{1,2})[\-\/\.]([0-9]{2})$/,
			parser: function (match) {
				return Date.UTC(+match[3] + 2000, match[1] - 1, +match[2]);
			}
		}
	},
	
	/**
	 * Parse a date and return it as a number. Overridable through options.parseDate.
	 */
	parseDate: function (val) {
		var parseDate = this.options.parseDate,
			ret,
			key,
			format,
			dateFormat = this.options.dateFormat || this.dateFormat,
			match;

		if (parseDate) {
			ret = parseDate(val);
		
		} else if (typeof val === 'string') {
			// Auto-detect the date format the first time
			if (!dateFormat) {
				for (key in this.dateFormats) {
					format = this.dateFormats[key];
					match = val.match(format.regex);
					if (match) {
						this.dateFormat = dateFormat = key;
						this.alternativeFormat = format.alternative;
						ret = format.parser(match);
						break;
					}
				}
			// Next time, use the one previously found
			} else {
				format = this.dateFormats[dateFormat];
				match = val.match(format.regex);
				if (match) {
					ret = format.parser(match);
				}
			}
			// Fall back to Date.parse		
			if (!match) {
				match = Date.parse(val);
				// External tools like Date.js and MooTools extend Date object and
				// returns a date.
				if (typeof match === 'object' && match !== null && match.getTime) {
					ret = match.getTime() - match.getTimezoneOffset() * 60000;
				
				// Timestamp
				} else if (typeof match === 'number' && !isNaN(match)) {
					ret = match - (new Date(match)).getTimezoneOffset() * 60000;
				}
			}
		}
		return ret;
	},
	
	/**
	 * Reorganize rows into columns
	 */
	rowsToColumns: function (rows) {
		var row,
			rowsLength,
			col,
			colsLength,
			columns;

		if (rows) {
			columns = [];
			rowsLength = rows.length;
			for (row = 0; row < rowsLength; row++) {
				colsLength = rows[row].length;
				for (col = 0; col < colsLength; col++) {
					if (!columns[col]) {
						columns[col] = [];
					}
					columns[col][row] = rows[row][col];
				}
			}
		}
		return columns;
	},
	
	/**
	 * A hook for working directly on the parsed columns
	 */
	parsed: function () {
		if (this.options.parsed) {
			return this.options.parsed.call(this, this.columns);
		}
	},

	getFreeIndexes: function (numberOfColumns, seriesBuilders) {
		var s,
			i,
			freeIndexes = [],
			freeIndexValues = [],
			referencedIndexes;

		// Add all columns as free
		for (i = 0; i < numberOfColumns; i = i + 1) {
			freeIndexes.push(true);
		}

		// Loop all defined builders and remove their referenced columns
		for (s = 0; s < seriesBuilders.length; s = s + 1) {
			referencedIndexes = seriesBuilders[s].getReferencedColumnIndexes();

			for (i = 0; i < referencedIndexes.length; i = i + 1) {
				freeIndexes[referencedIndexes[i]] = false;
			}
		}

		// Collect the values for the free indexes
		for (i = 0; i < freeIndexes.length; i = i + 1) {
			if (freeIndexes[i]) {
				freeIndexValues.push(i);
			}
		}

		return freeIndexValues;
	},
	
	/**
	 * If a complete callback function is provided in the options, interpret the 
	 * columns into a Highcharts options object.
	 */
	complete: function () {
		
		var columns = this.columns,
			xColumns = [],
			type,
			options = this.options,
			series,
			data,
			i,
			j,
			r,
			seriesIndex,
			chartOptions,
			allSeriesBuilders = [],
			builder,
			freeIndexes,
			typeCol,
			index;

		xColumns.length = columns.length;
		if (options.complete || options.afterComplete) {

			// Get the names and shift the top row
			for (i = 0; i < columns.length; i++) {
				if (this.firstRowAsNames) {
					columns[i].name = columns[i].shift();
				}
			}
			
			// Use the next columns for series
			series = [];
			freeIndexes = this.getFreeIndexes(columns.length, this.valueCount.seriesBuilders);

			// Populate defined series
			for (seriesIndex = 0; seriesIndex < this.valueCount.seriesBuilders.length; seriesIndex++) {
				builder = this.valueCount.seriesBuilders[seriesIndex];

				// If the builder can be populated with remaining columns, then add it to allBuilders
				if (builder.populateColumns(freeIndexes)) {
					allSeriesBuilders.push(builder);
				}
			}

			// Populate dynamic series
			while (freeIndexes.length > 0) {
				builder = new SeriesBuilder();
				builder.addColumnReader(0, 'x');
				
				// Mark index as used (not free)
				index = inArray(0, freeIndexes);
				if (index !== -1) {
					freeIndexes.splice(index, 1);
				}

				for (i = 0; i < this.valueCount.global; i++) {
					// Create and add a column reader for the next free column index
					builder.addColumnReader(undefined, this.valueCount.globalPointArrayMap[i]);
				}

				// If the builder can be populated with remaining columns, then add it to allBuilders
				if (builder.populateColumns(freeIndexes)) {
					allSeriesBuilders.push(builder);
				}
			}

			// Get the data-type from the first series x column
			if (allSeriesBuilders.length > 0 && allSeriesBuilders[0].readers.length > 0) {
				typeCol = columns[allSeriesBuilders[0].readers[0].columnIndex];
				if (typeCol !== undefined) {
					if (typeCol.isDatetime) {
						type = 'datetime';
					} else if (!typeCol.isNumeric) {
						type = 'category';
					}
				}
			}
			// Axis type is category, then the "x" column should be called "name"
			if (type === 'category') {
				for (seriesIndex = 0; seriesIndex < allSeriesBuilders.length; seriesIndex++) {
					builder = allSeriesBuilders[seriesIndex];
					for (r = 0; r < builder.readers.length; r++) {
						if (builder.readers[r].configName === 'x') {
							builder.readers[r].configName = 'name';
						}
					}
				}
			}

			// Read data for all builders
			for (seriesIndex = 0; seriesIndex < allSeriesBuilders.length; seriesIndex++) {
				builder = allSeriesBuilders[seriesIndex];

				// Iterate down the cells of each column and add data to the series
				data = [];
				for (j = 0; j < columns[0].length; j++) { // TODO: which column's length should we use here
					data[j] = builder.read(columns, j);
				}

				// Add the series
				series[seriesIndex] = {
					data: data
				};
				if (builder.name) {
					series[seriesIndex].name = builder.name;
				}
				if (type === 'category') {
					series[seriesIndex].turboThreshold = 0;
				}
			}



			// Do the callback
			chartOptions = {
				series: series
			};
			if (type) {
				chartOptions.xAxis = {
					type: type
				};
			}
			
			if (options.complete) {
				options.complete(chartOptions);
			}

			// The afterComplete hook is used internally to avoid conflict with the externally
			// available complete option.
			if (options.afterComplete) {
				options.afterComplete(chartOptions);
			}
		}
	}
	});
	
	// Register the Data prototype and data function on Highcharts
	Highcharts.Data = Data;
	Highcharts.data = function (options, chartOptions) {
		return new Data(options, chartOptions);
	};

	// Extend Chart.init so that the Chart constructor accepts a new configuration
	// option group, data.
	Highcharts.wrap(Highcharts.Chart.prototype, 'init', function (proceed, userOptions, callback) {
		var chart = this;

		if (userOptions && userOptions.data) {
			Highcharts.data(Highcharts.extend(userOptions.data, {

				afterComplete: function (dataOptions) {
					var i, series;
					
					// Merge series configs
					if (userOptions.hasOwnProperty('series')) {
						if (typeof userOptions.series === 'object') {
							i = Math.max(userOptions.series.length, dataOptions.series.length);
							while (i--) {
								series = userOptions.series[i] || {};
								userOptions.series[i] = Highcharts.merge(series, dataOptions.series[i]);
							}
						} else { // Allow merging in dataOptions.series (#2856)
							delete userOptions.series;
						}
					}

					// Do the merge
					userOptions = Highcharts.merge(dataOptions, userOptions);

					proceed.call(chart, userOptions, callback);
				}
			}), userOptions);
		} else {
			proceed.call(chart, userOptions, callback);
		}
	});

	/**
	 * Creates a new SeriesBuilder. A SeriesBuilder consists of a number
	 * of ColumnReaders that reads columns and give them a name.
	 * Ex: A series builder can be constructed to read column 3 as 'x' and
	 * column 7 and 8 as 'y1' and 'y2'.
	 * The output would then be points/rows of the form {x: 11, y1: 22, y2: 33}
	 * 
	 * The name of the builder is taken from the second column. In the above
	 * example it would be the column with index 7.
	 * @constructor
	 */
	SeriesBuilder = function () {
		this.readers = [];
		this.pointIsArray = true;
	};

	/**
	 * Populates readers with column indexes. A reader can be added without
	 * a specific index and for those readers the index is taken sequentially
	 * from the free columns (this is handled by the ColumnCursor instance).
	 * @returns {boolean}
	 */
	SeriesBuilder.prototype.populateColumns = function (freeIndexes) {
		var builder = this,
			enoughColumns = true;

		// Loop each reader and give it an index if its missing.
		// The freeIndexes.shift() will return undefined if there
		// are no more columns.
		each(builder.readers, function (reader) {
			if (reader.columnIndex === undefined) {
				reader.columnIndex = freeIndexes.shift();
			}
		});

		// Now, all readers should have columns mapped. If not
		// then return false to signal that this series should
		// not be added.
		each(builder.readers, function (reader) {
			if (reader.columnIndex === undefined) {
				enoughColumns = false;
			}
		});

		return enoughColumns;
	};

	/**
	 * Reads a row from the dataset and returns a point or array depending
	 * on the names of the readers.
	 * @param columns
	 * @param rowIndex
	 * @returns {Array | Object}
	 */
	SeriesBuilder.prototype.read = function (columns, rowIndex) {
		var builder = this,
			pointIsArray = builder.pointIsArray,
			point = pointIsArray ? [] : {},
			columnIndexes;

		// Loop each reader and ask it to read its value.
		// Then, build an array or point based on the readers names.
		each(builder.readers, function (reader) {
			var value = columns[reader.columnIndex][rowIndex];
			if (pointIsArray) {
				point.push(value);
			} else {
				point[reader.configName] = value; 
			}
		});

		// The name comes from the first column (excluding the x column)
		if (this.name === undefined && builder.readers.length >= 2) {
			columnIndexes = builder.getReferencedColumnIndexes();
			if (columnIndexes.length >= 2) {
				// remove the first one (x col)
				columnIndexes.shift();

				// Sort the remaining
				columnIndexes.sort();

				// Now use the lowest index as name column
				this.name = columns[columnIndexes.shift()].name;
			}
		}

		return point;
	};

	/**
	 * Creates and adds ColumnReader from the given columnIndex and configName.
	 * ColumnIndex can be undefined and in that case the reader will be given
	 * an index when columns are populated.
	 * @param columnIndex {Number | undefined}
	 * @param configName
	 */
	SeriesBuilder.prototype.addColumnReader = function (columnIndex, configName) {
		this.readers.push({
			columnIndex: columnIndex, 
			configName: configName
		});

		if (!(configName === 'x' || configName === 'y' || configName === undefined)) {
			this.pointIsArray = false;
		}
	};

	/**
	 * Returns an array of column indexes that the builder will use when
	 * reading data.
	 * @returns {Array}
	 */
	SeriesBuilder.prototype.getReferencedColumnIndexes = function () {
		var i,
			referencedColumnIndexes = [],
			columnReader;
		
		for (i = 0; i < this.readers.length; i = i + 1) {
			columnReader = this.readers[i];
			if (columnReader.columnIndex !== undefined) {
				referencedColumnIndexes.push(columnReader.columnIndex);
			}
		}

		return referencedColumnIndexes;
	};

	/**
	 * Returns true if the builder has a reader for the given configName.
	 * @param configName
	 * @returns {boolean}
	 */
	SeriesBuilder.prototype.hasReader = function (configName) {
		var i, columnReader;
		for (i = 0; i < this.readers.length; i = i + 1) {
			columnReader = this.readers[i];
			if (columnReader.configName === configName) {
				return true;
			}
		}
		// Else return undefined
	};



}(Highcharts));
