/**
* Grid()
* by Bachir Soussi-Chiadmi www.g-u-i.net
* version 2.0
*/
	
function Grid(ctx, settings){
	

	var _defaults = {
				children:'', // tell which dom elmt to target, by default $ctx.children();
				cell_w: 20, cell_h: 20,
				cell_padding:{t:5,r:5,b:5,l:5}, // with or without padding cell width and height are the same
				padding:{t:5,r:5,b:5,l:5}, // padding (in cell) inside the grid where not placed element
				gouttiere: 5, // space between cells h and v
				lines: 20, columns: 20,// how much line and columns grid has
				grille: false, // see the grid with cell's free space infos
				groove: 0, // add groove attitude (randomize placement)
				positioning_mode:'random', // positioning_mode play with with the position on items
				max_distance:0, // distance max between prev item and current item. O = no limit
				min_distance:0, // distance min between prev item and current item. O = no limit
			},
		$ctx = ctx,
		_cells = new Array(),
		_positions = new Array(),
		_grid = this;

	this.ctx = $ctx;
	this.settings = $.extend({}, _defaults, settings);

	
	
	// $.log('this.settings', this.settings);

	// set dom grille visualsation context if enabled
	if (this.settings.grille) {
		$ctx.append('<div class="grille"><div>');
		$('.grille', $ctx).css({
		   'width': '100%',
		   'height': '100%',
		   'position': 'relative'
		});
	}

	// create all empty cells
	for (var l = 0; l < this.settings.lines; l++) {
	  _cells[l] = new Array();
	  for (var c = 0; c < this.settings.columns; c++) {
	    _cells[l][c] = new Cell(this, c, l);
	  };
	};
	

	function _setPrevCell(){
		// _grid.prev_cell = false;
		switch(_grid.settings.positioning_mode){
			case 'lefttop': // add items from top left to bootm rif-ght
					_grid.prev_cell = _cells[0][0];
				break;
			case 'center': // add items from center of grid to both side randomly
					_grid.prev_cell = _cells[Math.floor(_grid.settings.lines*.5)][Math.floor(_grid.settings.columns*.5)];
					break;
			case 'borders': // add items from center of grid to both side randomly
					var side = Math.floor(Math.random()*4);
					$.log('side = '+side);
					switch(side){
						case 0 :
							_grid.prev_cell = _cells[0][Math.floor(_grid.settings.columns*Math.random())];
							break;
						case 1 :
							_grid.prev_cell = _cells[_grid.settings.lines-1][Math.floor(_grid.settings.columns*Math.random())];
							break;
						case 2 :
							_grid.prev_cell = _cells[Math.floor(_grid.settings.lines*Math.random())][0];
							break;
						case 3 :
							_grid.prev_cell = _cells[Math.floor(_grid.settings.lines*Math.random())][_grid.settings.columns-1];
							break;
					}
					break;
			case 'random': // add items randomly
			default:
					_grid.prev_cell = _cells[Math.floor(_grid.settings.lines*Math.random())][Math.floor(_grid.settings.columns*Math.random())];
				break;
		}
		
	}
	_setPrevCell();


	/**
	* placeTargets()
	*/
	function _placeTargets(){
		// parse targets
		var $targets = _grid.settings.children != '' ? $(_grid.settings.children+':not(.grid-placed)', $ctx) : $ctx.children(':not(.grid-placed)');

		$targets.each(function() {

		  var $this = $(this),
					// get the width and height ( ! on cell unit ! how much cells it takes ? ) of item to be positioned
					this_cells_w = Math.ceil($this.width() / (_grid.settings.cell_w + _grid.settings.gouttiere)),
					this_cells_h = Math.ceil($this.height() / (_grid.settings.cell_h + _grid.settings.gouttiere)),
					// get free cells function of width and height of item
					free_cells = getFreeCells(this_cells_w, this_cells_h);
			if(free_cells.length > 0){

				// positioning mode, to change this mode uncomment/comment lines after description
				switch(_grid.settings.positioning_mode){
					case 'lefttop': // add items from top left to bootm rif-ght
							var cell_num = 0,
									cell = free_cells[cell_num];
						break;
					default: // add items from center of grid to both side randomly
							// var cell_num = Math.floor((free_cells.length-1)*0.5 + (-2+Math.random()*4));
							// cell_num = cell_num > free_cells.length-1 ? free_cells.length-1 : ( cell_num < 0 ? 0 : cell_num );
							// var cell = free_cells[cell_num];
							var cell_num = Math.round(Math.random() * (free_cells.length - 1)),
									cell = free_cells[cell_num];
						break;
				}

				_grid.prev_cell = cell;

				var line_limit_loop = cell.row() + (this_cells_h),
						column_limit_loop = cell.column() + (this_cells_w);

		    for (var l = cell.row(); l < line_limit_loop; l++) {
		        for (var c = cell.column(); c < column_limit_loop; c++) {
		            var temp_cell = _cells[l][c];
		            temp_cell.setFull();
		        };
		    };

				// get tp and left coordinates
				// should be directly recorded in the cell object
		    var top = cell.row() * (_grid.settings.cell_h + _grid.settings.gouttiere),
						left = cell.column() * (_grid.settings.cell_w + _grid.settings.gouttiere),
						groove = _grid.settings.groove;

				// set groove ;)
				top = !groove ? top: top + Math.round(Math.random() * groove - groove / 2);
				left = !groove ? left: left + Math.round(Math.random() * groove - groove / 2);

				// apply ccs position
				top += _grid.settings.cell_padding.t;
				left += _grid.settings.cell_padding.l;
				
				var event = jQuery.Event("grid_positioned");
				event.top = top;
				event.left = left;
				
		    $this.css({
	        'top': top,
	        'left': left
		    }).addClass('grid-positioned').trigger(event);
			}else{
				$.log('GRID no free cells left');
				// if no free cells exist
				$this.css({
					'border': '2px solid red',
					'opacity': 0.2
				}).trigger('grid_removed');//.remove();
		  }
			$this.addClass('grid-placed').trigger('grid_placed');
		}); // end children each
	
	}
	
	
	/**
	* getFreeCells()
	*
	* @ width in cells
	* @ height in cells
	*
	* return array of cell objects
	*
	*/
	function getFreeCells(this_cells_w, this_cells_h){
		
		var free_cells = new Array(),
				padding = _grid.settings.padding,
				max_dist = _grid.settings.max_distance,
				min_dist = _grid.settings.min_distance,
				prev_cell = _grid.prev_cell;
		
		// $.log()
		
		for (var l = 0; l < _grid.settings.lines; l++) {
			for (var c = 0; c < _grid.settings.columns; c++) {
				var cell = _cells[l][c];
				
				/*
					TODO about the max_dist keep in mind that all element will not always be 1 cell elemnts !!
				*/
				
				// here is a big stuff of conditionning
				// we check a lot of things
				// 1 - basicly if the cell is free
				// 2 - if the cell is under the padding limits
				// 3 - if she has enought space arround her
				// 4 - if we got a prev cell
				//	4.1 - if we got a max_dist != 0
				//		4.1.1 - if the cell is under the max limits
				//	4.2 - if we got a min_dist != 0
				//		4.2.1 - if the cell is behind the min limits
				
				if (cell.isFree() // if cell is free
						&& (cell.row() > padding.t && cell.row() < _grid.settings.lines - padding.b
								&& cell.column() > padding.l && cell.column() < _grid.settings.columns - padding.r
							)
						&& (
								(cell.getAround().right + 1) >= this_cells_w // if enought free space on the right
								&& (cell.getAround().bottom + 1) >= this_cells_h // if enought free space on the bottom
							)
						&& ( !_grid.prev_cell // else if _grid.prev_cell undefined it's true
							|| ( // check max_dist AND min_dist
									(!max_dist // if max_distance is 0 return (stop condition) true
									|| ( cell.row() < prev_cell.row()+max_dist && cell.row() > prev_cell.row()-max_dist
											&& cell.column() < prev_cell.column()+max_dist && cell.column() > prev_cell.column()-max_dist )// if we got max_distance and prev_cell we check the distance
									) 
								&& 
									(!min_dist // if min_distance is 0 return (stop condition) true
									|| ( (cell.row() > prev_cell.row()+min_dist || cell.row() < prev_cell.row()-min_dist)
											|| (cell.column() > prev_cell.column()+min_dist || cell.column() < prev_cell.column()-min_dist) )// if we got min_distance and prev_cell we check the distance
									) 
								)
							)
					) { // true of first big stuff if
					var good = true;
					for (var i = 1; i < this_cells_w; i++) { // for each free cells needed on right
						var temp_cell = _cells[l][c + i];
						if ((temp_cell.getAround().bottom + 1) < this_cells_h) { // if enought free space on bottom
							good = false;
							break;
						}
					};
					if (good) free_cells.push(cell);
				}
			};
		};
	
		return free_cells;
	}

	/**
	* Cell()
	*/
	function Cell(g, c, r) {
	  var _grid = g,
			_column = c,
	    _row = r,
	    _free = true,
	    _free_cell_right = _grid.settings.columns - 1 - c,
	    _free_cell_bottom = _grid.settings.lines - 1 - l;

	  if (_grid.settings.grille) {
	      var _table = '<table>';
	      _table += '<tr><td>&nbsp;</td><td>&nbsp;</td><td>&nbsp;</td></tr>';
	      // _table += '<tr><td>&nbsp;</td><td class="state">'+_free+'</td><td class="fr">'+_free_cell_right+'</td></tr>';
	      _table += '<tr><td>&nbsp;</td><td>&nbsp;</td><td class="fr">' + _free_cell_right + '</td></tr>';
	      _table += '<tr><td>&nbsp;</td><td class="fb">' + _free_cell_bottom + '</td><td>&nbsp;</td></tr>';
	      _table += '</table>';
	      _grid.ctx.find('.grille').append('<div class="cell-' + l + '-' + c + '">' + _table + '<div>');
	      var _dom = $('.cell-' + l + '-' + c, _grid.ctx.find('.grille'));
	      _dom.css({
	          'position': 'absolute',
	          'top': _row * (_grid.settings.cell_h + _grid.settings.gouttiere) + _grid.settings.cell_padding.t,
	          'left': _column * (_grid.settings.cell_w + _grid.settings.gouttiere) + _grid.settings.cell_padding.l,
	          'width': _grid.settings.cell_w,
	          'height': _grid.settings.cell_h,
	          'backgroundColor': '#00FF00',
	          'opacity': 0.6
	      });
	      // $('td', _dom).css({
	      //     'fontSize': '8px'
	      // });
	  }

	  this.isFree = function() { return _free; };

	  this.getPos = function() { return { c: _column, l: _row }; };
		this.column = function() { return _column; };
		this.row = function() { return _row; };

	  this.getAround = function() { return { right: _free_cell_right, bottom: _free_cell_bottom }; };

	  this.setFull = function() {

	      _free = false;
	      _free_cell_bottom = -1;
	      _free_cell_right = -1;

	      if (_grid.settings.grille) {
	          _dom.css({
	              'backgroundColor': '#0000FF'
	          });
	          $('.fb', _dom).html(_free_cell_bottom);
	          $('.fr', _dom).html(_free_cell_right);
	      }

	      _propageFreeCells();
	  };

	  this.setFreeCellsRight = function(right) {
	      if (_free) {
	          // $.log('_setFreeCellRigth | _free_cell_right = ' + _free_cell_right + ' | new right = ' + right);
	          _free_cell_right = right;
	          if (_grid.settings.grille) $('.fr', _dom).html(_free_cell_right);
	          _propageFreeCellsLeft();
	      }
	  };

	  this.setFreeCellsBottom = function(bottom) {
	      if (_free) {
	          // $.log('_setFreeCellsBottom | _free_cell_bottom = ' + _free_cell_bottom + ' | new right = ' + bottom);
	          _free_cell_bottom = bottom;
	          if (_grid.settings.grille) $('.fb', _dom).html(_free_cell_bottom);
	          _propageFreeCellsTop();
	      }
	  };

	  function _propageFreeCells() {
	      // $.log('_propageFreeCells');
	      _propageFreeCellsLeft();
	      _propageFreeCellsTop();
	  };

	  function _propageFreeCellsLeft() {
	      // $.log('_propageFreeCellsLeft | _column = '+_column);
	      if (_column > 0) {
	          var left_cel = _cells[_row][_column - 1];
	          left_cel.setFreeCellsRight(_free_cell_right + 1);
	      }
	  };

	  function _propageFreeCellsTop() {
	      // $.log('_propageFreeCellsTop | _row = '+_row);
	      if (_row > 0) {
	          var top_cel = _cells[_row - 1][_column];
	          top_cel.setFreeCellsBottom(_free_cell_bottom + 1);
	      }
	  };

	  if (typeof Cell.initialized == "undefined") {
	      Cell.prototype.infos = function() {
	          $.log('cell | column = ' + this.column() + ', line = ' + this.row() + ', free = ' + this.isFree() + ', free cell right = ' + this.getAround().right + ', free cell bottom = ' + this.getAround().bottom);
	      };

	      Cell.initialized = true;
	  }
	}; // cell()
	
	if (typeof Node.initialized == "undefined") {

    Grid.prototype.refresh = function() {
			_placeTargets();
		};

    Grid.prototype.resetPrevCell = function() {
			_setPrevCell();
			// this.prev_cell = false;
		};


		Node.initialized = true;

  }
	
	
};

(function($) {
	$.fn.grid = function(settings) {
		return this.each(function(index) {
			$(this).data('grid', new Grid(this, settings));
		});
	}
})(jQuery);