/**
 * Quirks.js
 *
 * Copyright, Moxiecode Systems AB
 * Released under LGPL License.
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/**
 * This class includes fixes for various browser quirks.
 *
 * @class tinymce.tableplugin.Quirks
 * @private
 */
define("tinymce/tableplugin/Quirks", [
	"tinymce/util/VK",
	"tinymce/Env",
	"tinymce/util/Tools"
], function(VK, Env, Tools) {
	var each = Tools.each;

	function getSpanVal(td, name) {
		return parseInt(td.getAttribute(name) || 1, 10);
	}

	return function(editor) {
		/**
		 * Fixed caret movement around tables on WebKit.
		 */
		function moveWebKitSelection() {
			function eventHandler(e) {
				var key = e.keyCode;

				function handle(upBool, sourceNode) {
					var siblingDirection = upBool ? 'previousSibling' : 'nextSibling';
					var currentRow = editor.dom.getParent(sourceNode, 'tr');
					var siblingRow = currentRow[siblingDirection];

					if (siblingRow) {
						moveCursorToRow(editor, sourceNode, siblingRow, upBool);
						e.preventDefault();
						return true;
					} else {
						var tableNode = editor.dom.getParent(currentRow, 'table');
						var middleNode = currentRow.parentNode;
						var parentNodeName = middleNode.nodeName.toLowerCase();
						if (parentNodeName === 'tbody' || parentNodeName === (upBool ? 'tfoot' : 'thead')) {
							var targetParent = getTargetParent(upBool, tableNode, middleNode, 'tbody');
							if (targetParent !== null) {
								return moveToRowInTarget(upBool, targetParent, sourceNode);
							}
						}
						return escapeTable(upBool, currentRow, siblingDirection, tableNode);
					}
				}

				function getTargetParent(upBool, topNode, secondNode, nodeName) {
					var tbodies = editor.dom.select('>' + nodeName, topNode);
					var position = tbodies.indexOf(secondNode);
					if (upBool && position === 0 || !upBool && position === tbodies.length - 1) {
						return getFirstHeadOrFoot(upBool, topNode);
					} else if (position === -1) {
						var topOrBottom = secondNode.tagName.toLowerCase() === 'thead' ? 0 : tbodies.length - 1;
						return tbodies[topOrBottom];
					} else {
						return tbodies[position + (upBool ? -1 : 1)];
					}
				}

				function getFirstHeadOrFoot(upBool, parent) {
					var tagName = upBool ? 'thead' : 'tfoot';
					var headOrFoot = editor.dom.select('>' + tagName, parent);
					return headOrFoot.length !== 0 ? headOrFoot[0] : null;
				}

				function moveToRowInTarget(upBool, targetParent, sourceNode) {
					var targetRow = getChildForDirection(targetParent, upBool);

					if (targetRow) {
						moveCursorToRow(editor, sourceNode, targetRow, upBool);
					}

					e.preventDefault();
					return true;
				}

				function escapeTable(upBool, currentRow, siblingDirection, table) {
					var tableSibling = table[siblingDirection];

					if (tableSibling) {
						moveCursorToStartOfElement(tableSibling);
						return true;
					} else {
						var parentCell = editor.dom.getParent(table, 'td,th');
						if (parentCell) {
							return handle(upBool, parentCell, e);
						} else {
							var backUpSibling = getChildForDirection(currentRow, !upBool);
							moveCursorToStartOfElement(backUpSibling);
							e.preventDefault();
							return false;
						}
					}
				}

				function getChildForDirection(parent, up) {
					var child =  parent && parent[up ? 'lastChild' : 'firstChild'];
					// BR is not a valid table child to return in this case we return the table cell
					return child && child.nodeName === 'BR' ? editor.dom.getParent(child, 'td,th') : child;
				}

				function moveCursorToStartOfElement(n) {
					editor.selection.setCursorLocation(n, 0);
				}

				function isVerticalMovement() {
					return key == VK.UP || key == VK.DOWN;
				}

				function isInTable(editor) {
					var node = editor.selection.getNode();
					var currentRow = editor.dom.getParent(node, 'tr');
					return currentRow !== null;
				}

				function columnIndex(column) {
					var colIndex = 0;
					var c = column;
					while (c.previousSibling) {
						c = c.previousSibling;
						colIndex = colIndex + getSpanVal(c, "colspan");
					}
					return colIndex;
				}

				function findColumn(rowElement, columnIndex) {
					var c = 0, r = 0;

					each(rowElement.children, function(cell, i) {
						c = c + getSpanVal(cell, "colspan");
						r = i;
						if (c > columnIndex) {
							return false;
						}
					});
					return r;
				}

				function moveCursorToRow(ed, node, row, upBool) {
					var srcColumnIndex = columnIndex(editor.dom.getParent(node, 'td,th'));
					var tgtColumnIndex = findColumn(row, srcColumnIndex);
					var tgtNode = row.childNodes[tgtColumnIndex];
					var rowCellTarget = getChildForDirection(tgtNode, upBool);
					moveCursorToStartOfElement(rowCellTarget || tgtNode);
				}

				function shouldFixCaret(preBrowserNode) {
					var newNode = editor.selection.getNode();
					var newParent = editor.dom.getParent(newNode, 'td,th');
					var oldParent = editor.dom.getParent(preBrowserNode, 'td,th');

					return newParent && newParent !== oldParent && checkSameParentTable(newParent, oldParent);
				}

				function checkSameParentTable(nodeOne, NodeTwo) {
					return editor.dom.getParent(nodeOne, 'TABLE') === editor.dom.getParent(NodeTwo, 'TABLE');
				}

				if (isVerticalMovement() && isInTable(editor)) {
					var preBrowserNode = editor.selection.getNode();
					setTimeout(function() {
						if (shouldFixCaret(preBrowserNode)) {
							handle(!e.shiftKey && key === VK.UP, preBrowserNode, e);
						}
					}, 0);
				}
			}

			editor.on('KeyDown', function(e) {
				eventHandler(e);
			});
		}

		function fixBeforeTableCaretBug() {
			// Checks if the selection/caret is at the start of the specified block element
			function isAtStart(rng, par) {
				var doc = par.ownerDocument, rng2 = doc.createRange(), elm;

				rng2.setStartBefore(par);
				rng2.setEnd(rng.endContainer, rng.endOffset);

				elm = doc.createElement('body');
				elm.appendChild(rng2.cloneContents());

				// Check for text characters of other elements that should be treated as content
				return elm.innerHTML.replace(/<(br|img|object|embed|input|textarea)[^>]*>/gi, '-').replace(/<[^>]+>/g, '').length === 0;
			}

			// Fixes an bug where it's impossible to place the caret before a table in Gecko
			// this fix solves it by detecting when the caret is at the beginning of such a table
			// and then manually moves the caret infront of the table
			editor.on('KeyDown', function(e) {
				var rng, table, dom = editor.dom;

				// On gecko it's not possible to place the caret before a table
				if (e.keyCode == 37 || e.keyCode == 38) {
					rng = editor.selection.getRng();
					table = dom.getParent(rng.startContainer, 'table');

					if (table && editor.getBody().firstChild == table) {
						if (isAtStart(rng, table)) {
							rng = dom.createRng();

							rng.setStartBefore(table);
							rng.setEndBefore(table);

							editor.selection.setRng(rng);

							e.preventDefault();
						}
					}
				}
			});
		}

		// Fixes an issue on Gecko where it's impossible to place the caret behind a table
		// This fix will force a paragraph element after the table but only when the forced_root_block setting is enabled
		function fixTableCaretPos() {
			editor.on('KeyDown SetContent VisualAid', function() {
				var last;

				// Skip empty text nodes from the end
				for (last = editor.getBody().lastChild; last; last = last.previousSibling) {
					if (last.nodeType == 3) {
						if (last.nodeValue.length > 0) {
							break;
						}
					} else if (last.nodeType == 1 && !last.getAttribute('data-mce-bogus')) {
						break;
					}
				}

				if (last && last.nodeName == 'TABLE') {
					if (editor.settings.forced_root_block) {
						editor.dom.add(
							editor.getBody(),
							editor.settings.forced_root_block,
							null,
							Env.ie ? '&nbsp;' : '<br data-mce-bogus="1" />'
						);
					} else {
						editor.dom.add(editor.getBody(), 'br', {'data-mce-bogus': '1'});
					}
				}
			});

			editor.on('PreProcess', function(o) {
				var last = o.node.lastChild;

				if (last && (last.nodeName == "BR" || (last.childNodes.length == 1 &&
					(last.firstChild.nodeName == 'BR' || last.firstChild.nodeValue == '\u00a0'))) &&
					last.previousSibling && last.previousSibling.nodeName == "TABLE") {
					editor.dom.remove(last);
				}
			});
		}

		// this nasty hack is here to work around some WebKit selection bugs.
		function fixTableCellSelection() {
			function tableCellSelected(ed, rng, n, currentCell) {
				// The decision of when a table cell is selected is somewhat involved.  The fact that this code is
				// required is actually a pointer to the root cause of this bug. A cell is selected when the start
				// and end offsets are 0, the start container is a text, and the selection node is either a TR (most cases)
				// or the parent of the table (in the case of the selection containing the last cell of a table).
				var TEXT_NODE = 3, table = ed.dom.getParent(rng.startContainer, 'TABLE');
				var tableParent, allOfCellSelected, tableCellSelection;

				if (table) {
					tableParent = table.parentNode;
				}

				allOfCellSelected =rng.startContainer.nodeType == TEXT_NODE &&
					rng.startOffset === 0 &&
					rng.endOffset === 0 &&
					currentCell &&
					(n.nodeName == "TR" || n == tableParent);

				tableCellSelection = (n.nodeName == "TD" || n.nodeName == "TH") && !currentCell;

				return allOfCellSelected || tableCellSelection;
			}

			function fixSelection() {
				var rng = editor.selection.getRng();
				var n = editor.selection.getNode();
				var currentCell = editor.dom.getParent(rng.startContainer, 'TD,TH');

				if (!tableCellSelected(editor, rng, n, currentCell)) {
					return;
				}

				if (!currentCell) {
					currentCell=n;
				}

				// Get the very last node inside the table cell
				var end = currentCell.lastChild;
				while (end.lastChild) {
					end = end.lastChild;
				}

				// Select the entire table cell. Nothing outside of the table cell should be selected.
				rng.setEnd(end, end.nodeValue.length);
				editor.selection.setRng(rng);
			}

			editor.on('KeyDown', function() {
				fixSelection();
			});

			editor.on('MouseDown', function(e) {
				if (e.button != 2) {
					fixSelection();
				}
			});
		}

		if (Env.webkit) {
			moveWebKitSelection();
			fixTableCellSelection();
		}

		if (Env.gecko) {
			fixBeforeTableCaretBug();
			fixTableCaretPos();
		}
	};
});