/*! RowReorder 1.0.0
 * 2015 SpryMedia Ltd - datatables.net/license
 */

/**
 * @summary     RowReorder
 * @description Row reordering extension for DataTables
 * @version     1.0.0
 * @file        dataTables.rowReorder.js
 * @author      SpryMedia Ltd (www.sprymedia.co.uk)
 * @contact     www.sprymedia.co.uk/contact
 * @copyright   Copyright 2015 SpryMedia Ltd.
 *
 * This source file is free software, available under the following license:
 *   MIT license - http://datatables.net/license/mit
 *
 * This source file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the license files for details.
 *
 * For details please refer to: http://www.datatables.net
 */

(function(window, document, undefined) {


var factory = function( $, DataTable ) {
"use strict";

/**
 * RowReorder provides the ability in DataTables to click and drag rows to
 * reorder them. When a row is dropped the data for the rows effected will be
 * updated to reflect the change. Normally this data point should also be the
 * column being sorted upon in the DataTable but this does not need to be the
 * case. RowReorder implements a "data swap" method - so the rows being
 * reordered take the value of the data point from the row that used to occupy
 * the row's new position.
 *
 * Initialisation is done by either:
 *
 * * `rowReorder` parameter in the DataTable initialisation object
 * * `new $.fn.dataTable.RowReorder( table, opts )` after DataTables
 *   initialisation.
 * 
 *  @class
 *  @param {object} settings DataTables settings object for the host table
 *  @param {object} [opts] Configuration options
 *  @requires jQuery 1.7+
 *  @requires DataTables 1.10.7+
 */
var RowReorder = function ( dt, opts ) {
	// Sanity check that we are using DataTables 1.10 or newer
	if ( ! DataTable.versionCheck || ! DataTable.versionCheck( '1.10.8' ) ) {
		throw 'DataTables RowReorder requires DataTables 1.10.8 or newer';
	}

	// User and defaults configuration object
	this.c = $.extend( true, {},
		DataTable.defaults.rowReorder,
		RowReorder.defaults,
		opts
	);

	// Internal settings
	this.s = {
		/** @type {integer} Scroll body top cache */
		bodyTop: null,

		/** @type {DataTable.Api} DataTables' API instance */
		dt: new DataTable.Api( dt ),

		/** @type {function} Data fetch function */
		getDataFn: DataTable.ext.oApi._fnGetObjectDataFn( this.c.dataSrc ),

		/** @type {array} Pixel positions for row insertion calculation */
		middles: null,

		/** @type {function} Data set function */
		setDataFn: DataTable.ext.oApi._fnSetObjectDataFn( this.c.dataSrc ),

		/** @type {Object} Mouse down information */
		start: {
			top: 0,
			left: 0,
			offsetTop: 0,
			offsetLeft: 0,
			nodes: []
		},

		/** @type {integer} Window height cached value */
		windowHeight: 0
	};

	// DOM items
	this.dom = {
		/** @type {jQuery} Cloned row being moved around */
		clone: null
	};

	// Check if row reorder has already been initialised on this table
	var settings = this.s.dt.settings()[0];
	var exisiting = settings.rowreorder;
	if ( exisiting ) {
		return exisiting;
	}

	settings.rowreorder = this;
	this._constructor();
};


RowReorder.prototype = {
	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	 * Constructor
	 */

	/**
	 * Initialise the RowReorder instance
	 *
	 * @private
	 */
	_constructor: function ()
	{
		var that = this;
		var dt = this.s.dt;
		var table = $( dt.table().node() );

		// Need to be able to calculate the row positions relative to the table
		if ( table.css('position') === 'static' ) {
			table.css( 'position', 'relative' );
		}

		// listen for mouse down on the target column - we have to implement
		// this rather than using HTML5 drag and drop as drag and drop doesn't
		// appear to work on table rows at this time. Also mobile browsers are
		// not supported
		$( table ).on( 'mousedown.rowReorder touchstart.rowReorder', this.c.selector, function (e) {
			var tr = $(this).closest('tr');

			// Double check that it is a DataTable row
			if ( dt.row( tr ).any() ) {
				that._mouseDown( e, tr );
				return false;
			}
		} );

		dt.on( 'destroy', function () {
			table.off( 'mousedown.rowReorder' );
		} );
	},


	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
	 * Private methods
	 */
	
	/**
	 * Cache the measurements that RowReorder needs in the mouse move handler
	 * to attempt to speed things up, rather than reading from the DOM.
	 *
	 * @private
	 */
	_cachePositions: function ()
	{
		var dt = this.s.dt;

		// Frustratingly, if we add `position:relative` to the tbody, the
		// position is still relatively to the parent. So we need to adjust
		// for that
		var headerHeight = $( dt.table().node() ).find('thead').outerHeight();

		// Need to pass the nodes through jQuery to get them in document order,
		// not what DataTables thinks it is, since we have been altering the
		// order
		var nodes = $.unique( dt.rows( { page: 'current' } ).nodes().toArray() );
		var tops = $.map( nodes, function ( node, i ) {
			return $(node).position().top - headerHeight;
		} );

		var middles = $.map( tops, function ( top, i ) {
			return tops.length < i-1 ?
				(top + tops[i+1]) / 2 :
				(top + top + $( dt.row( ':last-child' ).node() ).outerHeight() ) / 2;
		} );

		this.s.middles = middles;
		this.s.bodyTop = $( dt.table().body() ).offset().top;
		this.s.windowHeight = $(window).height();
	},


	/**
	 * Clone a row so it can be floated around the screen
	 *
	 * @param  {jQuery} target Node to be cloned
	 * @private
	 */
	_clone: function ( target )
	{
		var dt = this.s.dt;
		var clone = $( dt.table().node().cloneNode(false) )
			.addClass( 'dt-rowReorder-float' )
			.append('<tbody/>')
			.append( target.clone( false ) );

		// Match the table and column widths - read all sizes before setting
		// to reduce reflows
		var tableWidth = target.outerWidth();
		var tableHeight = target.outerHeight();
		var sizes = target.children().map( function () {
			return $(this).width();
		} );

		clone
			.width( tableWidth )
			.height( tableHeight )
			.find('tr').children().each( function (i) {
				this.style.width = sizes[i]+'px';
			} );

		// Insert into the document to have it floating around
		clone.appendTo( 'body' );

		this.dom.clone = clone;
	},


	/**
	 * Update the cloned item's position in the document
	 *
	 * @param  {object} e Event giving the mouse's position
	 * @private
	 */
	_clonePosition: function ( e )
	{
		var start = this.s.start;
		var topDiff = this._eventToPage( e, 'Y' ) - start.top;
		var leftDiff = this._eventToPage( e, 'X' ) - start.left;
		var snap = this.c.snapX;
		var left;

		if ( snap === true ) {
			left = start.offsetLeft;
		}
		else if ( typeof snap === 'number' ) {
			left = start.offsetLeft + snap;
		}
		else {
			left = leftDiff + start.offsetLeft;
		}

		this.dom.clone.css( {
			top: topDiff + start.offsetTop,
			left: left
		} );
	},


	/**
	 * Emit an event on the DataTable for listeners
	 *
	 * @param  {string} name Event name
	 * @param  {array} args Event arguments
	 * @private
	 */
	_emitEvent: function ( name, args )
	{
		this.s.dt.iterator( 'table', function ( ctx, i ) {
			$(ctx.nTable).triggerHandler( name+'.dt', args );
		} );
	},


	/**
	 * Get pageX/Y position from an event, regardless of if it is a mouse or
	 * touch event.
	 *
	 * @param  {object} e Event
	 * @param  {string} pos X or Y (must be a capital)
	 * @private
	 */
	_eventToPage: function ( e, pos )
	{
		if ( e.type.indexOf( 'touch' ) !== -1 ) {
			return e.originalEvent.touches[0][ 'page'+pos ];
		}

		return e[ 'page'+pos ];
	},


	/**
	 * Mouse down event handler. Read initial positions and add event handlers
	 * for the move.
	 *
	 * @param  {object} e      Mouse event
	 * @param  {jQuery} target TR element that is to be moved
	 * @private
	 */
	_mouseDown: function ( e, target )
	{
		var that = this;
		var dt = this.s.dt;
		var start = this.s.start;

		var offset = target.offset();
		start.top = this._eventToPage( e, 'Y' );
		start.left = this._eventToPage( e, 'X' );
		start.offsetTop = offset.top;
		start.offsetLeft = offset.left;
		start.nodes = $.unique( dt.rows( { page: 'current' } ).nodes().toArray() );

		this._cachePositions();
		this._clone( target );
		this._clonePosition( e );

		this.dom.target = target;
		target.addClass( 'dt-rowReorder-moving' );

		$( document )
			.on( 'mouseup.rowReorder touchend.rowReorder', function (e) {
				that._mouseUp(e);
			} )
			.on( 'mousemove.rowReorder touchmove.rowReorder', function (e) {
				that._mouseMove(e);
			} );

		// Check if window is x-scrolling - if not, disable it for the duration
		// of the drag
		if ( $(window).width() === $(document).width() ) {
			$(document.body).addClass( 'dt-rowReorder-noOverflow' );
		}
	},


	/**
	 * Mouse move event handler - move the cloned row and shuffle the table's
	 * rows if required.
	 *
	 * @param  {object} e Mouse event
	 * @private
	 */
	_mouseMove: function ( e )
	{
		this._clonePosition( e );

		// Transform the mouse position into a position in the table's body
		var bodyY = this._eventToPage( e, 'Y' ) - this.s.bodyTop;
		var middles = this.s.middles;
		var insertPoint = null;
		var dt = this.s.dt;
		var body = dt.table().body();

		// Determine where the row should be inserted based on the mouse
		// position
		for ( var i=0, ien=middles.length ; i<ien ; i++ ) {
			if ( bodyY < middles[i] ) {
				insertPoint = i;
				break;
			}
		}

		if ( insertPoint === null ) {
			insertPoint = middles.length;
		}

		// Perform the DOM shuffle if it has changed from last time
		if ( this.s.lastInsert === null || this.s.lastInsert !== insertPoint ) {
			if ( insertPoint === 0 ) {
				this.dom.target.prependTo( body );
			}
			else {
				var nodes = $.unique( dt.rows( { page: 'current' } ).nodes().toArray() );

				if ( insertPoint > this.s.lastInsert ) {
					this.dom.target.before( nodes[ insertPoint-1 ] );
				}
				else {
					this.dom.target.after( nodes[ insertPoint ] );
				}
			}

			this._cachePositions();

			this.s.lastInsert = insertPoint;
		}

		// scroll window up and down when reaching the edges
		var windowY = this._eventToPage( e, 'Y' ) - document.body.scrollTop;
		var scrollInterval = this.s.scrollInterval;

		if ( windowY < 65 ) {
			if ( ! scrollInterval ) {
				this.s.scrollInterval = setInterval( function () {
					document.body.scrollTop -= 5;
				}, 15 );
			}
		}
		else if ( this.s.windowHeight - windowY < 65 ) {
			if ( ! scrollInterval ) {
				this.s.scrollInterval = setInterval( function () {
					document.body.scrollTop += 5;
				}, 15 );
			}
		}
		else {
			clearInterval( scrollInterval );
			this.s.scrollInterval = null;
		}
	},


	/**
	 * Mouse up event handler - release the event handlers and perform the
	 * table updates
	 *
	 * @param  {object} e Mouse event
	 * @private
	 */
	_mouseUp: function ( e )
	{
		var dt = this.s.dt;
		var i, ien;

		this.dom.clone.remove();
		this.dom.clone = null;

		this.dom.target.removeClass( 'dt-rowReorder-moving' );
		//this.dom.target = null;

		$(document).off( '.rowReorder' );
		$(document.body).removeClass( 'dt-rowReorder-noOverflow' );

		// Calculate the difference
		var startNodes = this.s.start.nodes;
		var endNodes = $.unique( dt.rows( { page: 'current' } ).nodes().toArray() );
		var idDiff = {};
		var fullDiff = [];
		var diffNodes = [];
		var getDataFn = this.s.getDataFn;
		var setDataFn = this.s.setDataFn;

		for ( i=0, ien=startNodes.length ; i<ien ; i++ ) {
			if ( startNodes[i] !== endNodes[i] ) {
				var id = dt.row( endNodes[i] ).id();
				var endRowData = dt.row( endNodes[i] ).data();
				var startRowData = dt.row( startNodes[i] ).data();

				if ( id ) {
					idDiff[ id ] = getDataFn( startRowData );
				}

				fullDiff.push( {
					node: endNodes[i],
					oldData: getDataFn( endRowData ),
					newData: getDataFn( startRowData ),
					newPosition: i,
					oldPosition: $.inArray( endNodes[i], startNodes )
				} );

				diffNodes.push( endNodes[i] );
			}
		}
		
		// Emit event
		this._emitEvent( 'row-reorder', [ fullDiff, {
			dataSrc: this.c.dataSrc,
			nodes:   diffNodes,
			values:  idDiff
		} ] );

		// Editor interface
		if ( this.c.editor ) {
			this.c.editor
				.edit( diffNodes, false, {
					submit: 'changed'
				} )
				.multiSet( this.c.dataSrc, idDiff )
				.submit();
		}

		// Do update if required
		if ( this.c.update ) {
			for ( i=0, ien=fullDiff.length ; i<ien ; i++ ) {
				var row = dt.row( fullDiff[i].node );
				var rowData = row.data();

				setDataFn( rowData, fullDiff[i].newData );

				row.invalidate( 'data' );
			}

			dt.draw( false );
		}
	}
};



/**
 * RowReorder default settings for initialisation
 *
 * @namespace
 * @name RowReorder.defaults
 * @static
 */
RowReorder.defaults = {
	/**
	 * Data point in the host row's data source object for where to get and set
	 * the data to reorder. This will normally also be the sorting column.
	 *
	 * @type {Number}
	 */
	dataSrc: 0,

	/**
	 * Editor instance that will be used to perform the update
	 *
	 * @type {DataTable.Editor}
	 */
	editor: null,

	/**
	 * Drag handle selector. This defines the element that when dragged will
	 * reorder a row.
	 *
	 * @type {String}
	 */
	selector: 'td:first-child',

	/**
	 * Optionally lock the dragged row's x-position. This can be `true` to
	 * fix the position match the host table's, `false` to allow free movement
	 * of the row, or a number to define an offset from the host table.
	 *
	 * @type {Boolean|number}
	 */
	snapX: false,

	/**
	 * Update the table's data on drop
	 *
	 * @type {Boolean}
	 */
	update: true
};


/**
 * Version information
 *
 * @name RowReorder.version
 * @static
 */
RowReorder.version = '1.0.0';


$.fn.dataTable.RowReorder = RowReorder;
$.fn.DataTable.RowReorder = RowReorder;

// Attach a listener to the document which listens for DataTables initialisation
// events so we can automatically initialise
$(document).on( 'init.dt.dtr', function (e, settings, json) {
	if ( e.namespace !== 'dt' ) {
		return;
	}

	var init = settings.oInit.rowReorder;
	var defaults = DataTable.defaults.rowReorder;

	if ( init || defaults ) {
		var opts = $.extend( {}, init, defaults );

		if ( init !== false ) {
			new RowReorder( settings, opts  );
		}
	}
} );

return RowReorder;
}; // /factory


// Define as an AMD module if possible
if ( typeof define === 'function' && define.amd ) {
	define( ['jquery', 'datatables'], factory );
}
else if ( typeof exports === 'object' ) {
    // Node/CommonJS
    factory( require('jquery'), require('datatables') );
}
else if ( jQuery && !jQuery.fn.dataTable.RowReorder ) {
	// Otherwise simply initialise as normal, stopping multiple evaluation
	factory( jQuery, jQuery.fn.dataTable );
}


})(window, document);
