/**
 * CellSelection.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2015 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/**
 * This class handles table cell selection by faking it using a css class that gets applied
 * to cells when dragging the mouse from one cell to another.
 *
 * @class tinymce.tableplugin.CellSelection
 * @private
 */
define("tinymce/tableplugin/CellSelection", [
	"tinymce/tableplugin/TableGrid",
	"tinymce/dom/TreeWalker",
	"tinymce/util/Tools"
], function(TableGrid, TreeWalker, Tools) {
	return function(editor, selectionChange) {
		var dom = editor.dom, tableGrid, startCell, startTable, lastMouseOverTarget, hasCellSelection = true, resizing, dragging;

		function clear(force) {
			// Restore selection possibilities
			editor.getBody().style.webkitUserSelect = '';

			if (force || hasCellSelection) {
				editor.$('td[data-mce-selected],th[data-mce-selected]').removeAttr('data-mce-selected');
				hasCellSelection = false;
			}
		}

		var endSelection = function () {
			startCell = tableGrid = startTable = lastMouseOverTarget = null;
			selectionChange(false);
		};

		function isCellInTable(table, cell) {
			if (!table || !cell) {
				return false;
			}

			return table === dom.getParent(cell, 'table');
		}

		function cellSelectionHandler(e) {
			var sel, target = e.target, currentCell;

			if (resizing || dragging) {
				return;
			}

			// Fake mouse enter by keeping track of last mouse over
			if (target === lastMouseOverTarget) {
				return;
			}

			lastMouseOverTarget = target;

			if (startTable && startCell) {
				currentCell = dom.getParent(target, 'td,th');

				if (!isCellInTable(startTable, currentCell)) {
					currentCell = dom.getParent(startTable, 'td,th');
				}

				// Selection inside first cell is normal until we have expanted
				if (startCell === currentCell && !hasCellSelection) {
					return;
				}

				selectionChange(true);

				if (isCellInTable(startTable, currentCell)) {
					e.preventDefault();

					if (!tableGrid) {
						tableGrid = new TableGrid(editor, startTable, startCell);
						editor.getBody().style.webkitUserSelect = 'none';
					}

					tableGrid.setEndCell(currentCell);
					hasCellSelection = true;

					// Remove current selection
					sel = editor.selection.getSel();

					try {
						if (sel.removeAllRanges) {
							sel.removeAllRanges();
						} else {
							sel.empty();
						}
					} catch (ex) {
						// IE9 might throw errors here
					}
				}
			}
		}

		editor.on('SelectionChange', function(e) {
			if (hasCellSelection) {
				e.stopImmediatePropagation();
			}
		}, true);

		// Add cell selection logic
		editor.on('MouseDown', function(e) {
			if (e.button != 2 && !resizing && !dragging) {
				clear();

				startCell = dom.getParent(e.target, 'td,th');
				startTable = dom.getParent(startCell, 'table');
			}
		});

		editor.on('mouseover', cellSelectionHandler);

		editor.on('remove', function() {
			dom.unbind(editor.getDoc(), 'mouseover', cellSelectionHandler);
			clear();
		});

		editor.on('MouseUp', function() {
			var rng, sel = editor.selection, selectedCells, walker, node, lastNode;

			function setPoint(node, start) {
				var walker = new TreeWalker(node, node);

				do {
					// Text node
					if (node.nodeType == 3 && Tools.trim(node.nodeValue).length !== 0) {
						if (start) {
							rng.setStart(node, 0);
						} else {
							rng.setEnd(node, node.nodeValue.length);
						}

						return;
					}

					// BR element
					if (node.nodeName == 'BR') {
						if (start) {
							rng.setStartBefore(node);
						} else {
							rng.setEndBefore(node);
						}

						return;
					}
				} while ((node = (start ? walker.next() : walker.prev())));
			}

			// Move selection to startCell
			if (startCell) {
				if (tableGrid) {
					editor.getBody().style.webkitUserSelect = '';
				}

				// Try to expand text selection as much as we can only Gecko supports cell selection
				selectedCells = dom.select('td[data-mce-selected],th[data-mce-selected]');
				if (selectedCells.length > 0) {
					rng = dom.createRng();
					node = selectedCells[0];
					rng.setStartBefore(node);
					rng.setEndAfter(node);

					setPoint(node, 1);
					walker = new TreeWalker(node, dom.getParent(selectedCells[0], 'table'));

					do {
						if (node.nodeName == 'TD' || node.nodeName == 'TH') {
							if (!dom.getAttrib(node, 'data-mce-selected')) {
								break;
							}

							lastNode = node;
						}
					} while ((node = walker.next()));

					setPoint(lastNode);

					sel.setRng(rng);
				}

				editor.nodeChanged();
				endSelection();
			}
		});

		editor.on('KeyUp Drop SetContent', function(e) {
			clear(e.type == 'setcontent');
			endSelection();
			resizing = false;
		});

		editor.on('ObjectResizeStart ObjectResized', function(e) {
			resizing = e.type != 'objectresized';
		});

		editor.on('dragstart', function () {
			dragging = true;
		});

		editor.on('drop dragend', function () {
			dragging = false;
		});

		return {
			clear: clear
		};
	};
});