/*
 * FCKeditor - The text editor for Internet - http://www.fckeditor.net
 * Copyright (C) 2003-2007 Frederico Caldeira Knabben
 *
 * == BEGIN LICENSE ==
 *
 * Licensed under the terms of any of the following licenses at your
 * choice:
 *
 *  - GNU General Public License Version 2 or later (the "GPL")
 *    http://www.gnu.org/licenses/gpl.html
 *
 *  - GNU Lesser General Public License Version 2.1 or later (the "LGPL")
 *    http://www.gnu.org/licenses/lgpl.html
 *
 *  - Mozilla Public License Version 1.1 or later (the "MPL")
 *    http://www.mozilla.org/MPL/MPL-1.1.html
 *
 * == END LICENSE ==
 *
 * Controls the [Enter] keystroke behavior in a document.
 */

/*
 *	Constructor.
 *		@targetDocument : the target document.
 *		@enterMode : the behavior for the <Enter> keystroke.
 *			May be "p", "div", "br". Default is "p".
 *		@shiftEnterMode : the behavior for the <Shift>+<Enter> keystroke.
 *			May be "p", "div", "br". Defaults to "br".
 */
var FCKEnterKey = function( targetWindow, enterMode, shiftEnterMode )
{
	this.Window			= targetWindow ;
	this.EnterMode		= enterMode || 'p' ;
	this.ShiftEnterMode	= shiftEnterMode || 'br' ;

	// Setup the Keystroke Handler.
	var oKeystrokeHandler = new FCKKeystrokeHandler( false ) ;
	oKeystrokeHandler._EnterKey = this ;
	oKeystrokeHandler.OnKeystroke = FCKEnterKey_OnKeystroke ;

	oKeystrokeHandler.SetKeystrokes( [
		[ 13		, 'Enter' ],
		[ SHIFT + 13, 'ShiftEnter' ],
		[ 8			, 'Backspace' ],
		[ 46		, 'Delete' ]
	] ) ;

	oKeystrokeHandler.AttachToElement( targetWindow.document ) ;
}


function FCKEnterKey_OnKeystroke(  keyCombination, keystrokeValue )
{
	var oEnterKey = this._EnterKey ;

	try
	{
		switch ( keystrokeValue )
		{
			case 'Enter' :
				return oEnterKey.DoEnter() ;
				break ;

			case 'ShiftEnter' :
				return oEnterKey.DoShiftEnter() ;
				break ;

			case 'Backspace' :
				return oEnterKey.DoBackspace() ;
				break ;

			case 'Delete' :
				return oEnterKey.DoDelete() ;
		}
	}
	catch (e)
	{
		// If for any reason we are not able to handle it, go
		// ahead with the browser default behavior.
	}

	return false ;
}

/*
 * Executes the <Enter> key behavior.
 */
FCKEnterKey.prototype.DoEnter = function( mode, hasShift )
{
	this._HasShift = ( hasShift === true ) ;

	var sMode = mode || this.EnterMode ;

	if ( sMode == 'br' )
		return this._ExecuteEnterBr() ;
	else
		return this._ExecuteEnterBlock( sMode ) ;
}

/*
 * Executes the <Shift>+<Enter> key behavior.
 */
FCKEnterKey.prototype.DoShiftEnter = function()
{
	return this.DoEnter( this.ShiftEnterMode, true ) ;
}

/*
 * Executes the <Backspace> key behavior.
 */
FCKEnterKey.prototype.DoBackspace = function()
{
	var bCustom = false ;

	// Get the current selection.
	var oRange = new FCKDomRange( this.Window ) ;
	oRange.MoveToSelection() ;

	if ( !oRange.CheckIsCollapsed() )
		return false ;

	var oStartBlock = oRange.StartBlock ;
	var oEndBlock = oRange.EndBlock ;

	// The selection boundaries must be in the same "block limit" element
	if ( oRange.StartBlockLimit == oRange.EndBlockLimit && oStartBlock && oEndBlock )
	{
		if ( !oRange.CheckIsCollapsed() )
		{
			var bEndOfBlock = oRange.CheckEndOfBlock() ;

			oRange.DeleteContents() ;

			if ( oStartBlock != oEndBlock )
			{
				oRange.SetStart(oEndBlock,1) ;
				oRange.SetEnd(oEndBlock,1) ;

//				if ( bEndOfBlock )
//					oEndBlock.parentNode.removeChild( oEndBlock ) ;
			}

			oRange.Select() ;

			bCustom = ( oStartBlock == oEndBlock ) ;
		}

		if ( oRange.CheckStartOfBlock() )
		{
			var oCurrentBlock = oRange.StartBlock ;

			var ePrevious = FCKDomTools.GetPreviousSourceElement( oCurrentBlock, true, [ 'BODY', oRange.StartBlockLimit.nodeName ], ['UL','OL'] ) ;

			bCustom = this._ExecuteBackspace( oRange, ePrevious, oCurrentBlock ) ;
		}
		else if ( FCKBrowserInfo.IsGecko )
		{
			// Firefox looses the selection when executing CheckStartOfBlock, so we must reselect.
			oRange.Select() ;
		}
	}

	oRange.Release() ;
	return bCustom ;
}

FCKEnterKey.prototype._ExecuteBackspace = function( range, previous, currentBlock )
{
	var bCustom = false ;

	// We could be in a nested LI.
	if ( !previous && currentBlock && currentBlock.nodeName.IEquals( 'LI' ) && currentBlock.parentNode.parentNode.nodeName.IEquals( 'LI' ) )
	{
		this._OutdentWithSelection( currentBlock, range ) ;
		return true ;
	}

	if ( previous && previous.nodeName.IEquals( 'LI' ) )
	{
		var oNestedList = FCKDomTools.GetLastChild( previous, ['UL','OL'] ) ;

		while ( oNestedList )
		{
			previous = FCKDomTools.GetLastChild( oNestedList, 'LI' ) ;
			oNestedList = FCKDomTools.GetLastChild( previous, ['UL','OL'] ) ;
		}
	}

	if ( previous && currentBlock )
	{
		// If we are in a LI, and the previous block is not an LI, we must outdent it.
		if ( currentBlock.nodeName.IEquals( 'LI' ) && !previous.nodeName.IEquals( 'LI' ) )
		{
			this._OutdentWithSelection( currentBlock, range ) ;
			return true ;
		}

		// Take a reference to the parent for post processing cleanup.
		var oCurrentParent = currentBlock.parentNode ;

		var sPreviousName = previous.nodeName.toLowerCase() ;
		if ( FCKListsLib.EmptyElements[ sPreviousName ] != null || sPreviousName == 'table' )
		{
			FCKDomTools.RemoveNode( previous ) ;
			bCustom = true ;
		}
		else
		{
			// Remove the current block.
			FCKDomTools.RemoveNode( currentBlock ) ;

			// Remove any empty tag left by the block removal.
			while ( oCurrentParent.innerHTML.Trim().length == 0 )
			{
				var oParent = oCurrentParent.parentNode ;
				oParent.removeChild( oCurrentParent ) ;
				oCurrentParent = oParent ;
			}

			// Cleanup the previous and the current elements.
			FCKDomTools.TrimNode( currentBlock ) ;
			FCKDomTools.TrimNode( previous ) ;

			// Append a space to the previous.
			// Maybe it is not always desirable...
			// previous.appendChild( this.Window.document.createTextNode( ' ' ) ) ;

			// Set the range to the end of the previous element and bookmark it.
			range.SetStart( previous, 2 ) ;
			range.Collapse( true ) ;
			var oBookmark = range.CreateBookmark() ;

			// Move the contents of the block to the previous element and delete it.
			FCKDomTools.MoveChildren( currentBlock, previous ) ;

			// Place the selection at the bookmark.
			range.MoveToBookmark( oBookmark ) ;
			range.Select() ;

			bCustom = true ;
		}
	}

	return bCustom ;
}

/*
 * Executes the <Delete> key behavior.
 */
FCKEnterKey.prototype.DoDelete = function()
{
	// The <Delete> has the same effect as the <Backspace>, so we have the same
	// results if we just move to the next block and apply the same <Backspace> logic.

	var bCustom = false ;

	// Get the current selection.
	var oRange = new FCKDomRange( this.Window ) ;
	oRange.MoveToSelection() ;

	// There is just one special case for collapsed selections at the end of a block.
	if ( oRange.CheckIsCollapsed() && oRange.CheckEndOfBlock( FCKBrowserInfo.IsGeckoLike ) )
	{
		var oCurrentBlock = oRange.StartBlock ;

		var eNext = FCKDomTools.GetNextSourceElement( oCurrentBlock, true, [ oRange.StartBlockLimit.nodeName ], ['UL','OL'] ) ;

		bCustom = this._ExecuteBackspace( oRange, oCurrentBlock, eNext ) ;
	}

	oRange.Release() ;
	return bCustom ;
}

FCKEnterKey.prototype._ExecuteEnterBlock = function( blockTag, range )
{
	// Get the current selection.
	var oRange = range || new FCKDomRange( this.Window ) ;

	// If we don't have a range, move it to the selection.
	if ( !range )
		oRange.MoveToSelection() ;

	// The selection boundaries must be in the same "block limit" element.
	if ( oRange.StartBlockLimit == oRange.EndBlockLimit )
	{
		// If the StartBlock or EndBlock are not available (for text without a
		// block tag), we must fix them, by moving the text to a block.
		if ( !oRange.StartBlock )
			this._FixBlock( oRange, true, blockTag ) ;

		if ( !oRange.EndBlock )
			this._FixBlock( oRange, false, blockTag ) ;

		// Get the current blocks.
		var eStartBlock	= oRange.StartBlock ;
		var eEndBlock	= oRange.EndBlock ;

		// Delete the current selection.
		if ( !oRange.CheckIsEmpty() )
			oRange.DeleteContents() ;

		// If the selection boundaries are in the same block element
		if ( eStartBlock == eEndBlock )
		{
			var eNewBlock ;

			var bIsStartOfBlock	= oRange.CheckStartOfBlock() ;
			var bIsEndOfBlock	= oRange.CheckEndOfBlock() ;

			if ( bIsStartOfBlock && !bIsEndOfBlock )
			{
				eNewBlock = eStartBlock.cloneNode(false) ;

				if ( FCKBrowserInfo.IsGeckoLike )
					eNewBlock.innerHTML = GECKO_BOGUS ;

				// Place the new block before the current block element.
				eStartBlock.parentNode.insertBefore( eNewBlock, eStartBlock ) ;

				// This is tricky, but to make the new block visible correctly
				// we must select it.
				if ( FCKBrowserInfo.IsIE )
				{
					// Move the selection to the new block.
					oRange.MoveToNodeContents( eNewBlock ) ;

					oRange.Select() ;
				}

				// Move the selection to the new block.
				oRange.MoveToElementEditStart( eStartBlock ) ;
			}
			else
			{
				// Check if the selection is at the end of the block.
				if ( bIsEndOfBlock )
				{
					var sStartBlockTag = eStartBlock.tagName.toUpperCase() ;

					// If the entire block is selected, and we are in a LI, let's decrease its indentation.
					if ( bIsStartOfBlock && sStartBlockTag == 'LI' )
					{
						this._OutdentWithSelection( eStartBlock, oRange ) ;
						oRange.Release() ;
						return true ;
					}
					else
					{
						// If is a header tag, or we are in a Shift+Enter (#77),
						// create a new block element.
						if ( (/^H[1-6]$/).test( sStartBlockTag ) || this._HasShift )
							eNewBlock = this.Window.document.createElement( blockTag ) ;
						// Otherwise, duplicate the current block.
						else
						{
							eNewBlock = eStartBlock.cloneNode(false) ;
							this._RecreateEndingTree( eStartBlock, eNewBlock ) ;
						}

						if ( FCKBrowserInfo.IsGeckoLike )
						{
							eNewBlock.innerHTML = GECKO_BOGUS ;

							// If the entire block is selected, let's add a bogus in the start block.
							if ( bIsStartOfBlock )
								eStartBlock.innerHTML = GECKO_BOGUS ;
						}
					}
				}
				else
				{
					// Extract the contents of the block from the selection point to the end of its contents.
					oRange.SetEnd( eStartBlock, 2 ) ;
					var eDocFrag = oRange.ExtractContents() ;

					// Duplicate the block element after it.
					eNewBlock = eStartBlock.cloneNode(false) ;

					// It could be that we are in a LI with a child UL/OL. Insert a bogus to give us space to type.
					FCKDomTools.TrimNode( eDocFrag.RootNode ) ;
					if ( eDocFrag.RootNode.firstChild.nodeType == 1 && eDocFrag.RootNode.firstChild.tagName.toUpperCase().Equals( 'UL', 'OL' ) )
						eNewBlock.innerHTML = GECKO_BOGUS ;

					// Place the extracted contents in the duplicated block.
					eDocFrag.AppendTo( eNewBlock ) ;

					if ( FCKBrowserInfo.IsGecko )
					{
						// In Gecko, the last child node must be a bogus <br>.
						this._AppendBogusBr( eStartBlock ) ;
						this._AppendBogusBr( eNewBlock ) ;
					}
				}

				if ( eNewBlock )
				{
					FCKDomTools.InsertAfterNode( eStartBlock, eNewBlock ) ;

					// Move the selection to the new block.
					oRange.MoveToElementEditStart( eNewBlock ) ;

					if ( FCKBrowserInfo.IsGeckoLike )
						eNewBlock.scrollIntoView( false ) ;
				}
			}
		}
		else
		{
			// Move the selection to the end block.
			oRange.MoveToElementEditStart( eEndBlock ) ;
		}

		oRange.Select() ;
	}

	// Release the resources used by the range.
	oRange.Release() ;

	return true ;
}

FCKEnterKey.prototype._ExecuteEnterBr = function( blockTag )
{
	// Get the current selection.
	var oRange = new FCKDomRange( this.Window ) ;
	oRange.MoveToSelection() ;

	// The selection boundaries must be in the same "block limit" element.
	if ( oRange.StartBlockLimit == oRange.EndBlockLimit )
	{
		oRange.DeleteContents() ;

		// Get the new selection (it is collapsed at this point).
		oRange.MoveToSelection() ;

		var bIsStartOfBlock	= oRange.CheckStartOfBlock() ;
		var bIsEndOfBlock	= oRange.CheckEndOfBlock() ;

		var sStartBlockTag = oRange.StartBlock ? oRange.StartBlock.tagName.toUpperCase() : '' ;

		var bHasShift = this._HasShift ;

		if ( !bHasShift && sStartBlockTag == 'LI' )
			return this._ExecuteEnterBlock( null, oRange ) ;

		// If we are at the end of a header block.
		if ( !bHasShift && bIsEndOfBlock && (/^H[1-6]$/).test( sStartBlockTag ) )
		{
			FCKDebug.Output( 'BR - Header' ) ;

			// Insert a BR after the current paragraph.
			FCKDomTools.InsertAfterNode( oRange.StartBlock, this.Window.document.createElement( 'br' ) ) ;

			// The space is required by Gecko only to make the cursor blink.
			if ( FCKBrowserInfo.IsGecko )
				FCKDomTools.InsertAfterNode( oRange.StartBlock, this.Window.document.createTextNode( '' ) ) ;

			// IE and Gecko have different behaviors regarding the position.
			oRange.SetStart( oRange.StartBlock.nextSibling, FCKBrowserInfo.IsIE ? 3 : 1 ) ;
		}
		else
		{
			FCKDebug.Output( 'BR - No Header' ) ;

			var eBr = this.Window.document.createElement( 'br' ) ;

			oRange.InsertNode( eBr ) ;

			// The space is required by Gecko only to make the cursor blink.
			if ( FCKBrowserInfo.IsGecko )
				FCKDomTools.InsertAfterNode( eBr, this.Window.document.createTextNode( '' ) ) ;

			// If we are at the end of a block, we must be sure the bogus node is available in that block.
			if ( bIsEndOfBlock && FCKBrowserInfo.IsGeckoLike )
				this._AppendBogusBr( eBr.parentNode ) ;

			if ( FCKBrowserInfo.IsIE )
				oRange.SetStart( eBr, 4 ) ;
			else
				oRange.SetStart( eBr.nextSibling, 1 ) ;

		}

		// This collapse guarantees the cursor will be blinking.
		oRange.Collapse( true ) ;

		oRange.Select() ;
	}

	// Release the resources used by the range.
	oRange.Release() ;

	return true ;
}

// Transform a block without a block tag in a valid block (orphan text in the body or td, usually).
FCKEnterKey.prototype._FixBlock = function( range, isStart, blockTag )
{
	// Bookmark the range so we can restore it later.
	var oBookmark = range.CreateBookmark() ;

	// Collapse the range to the requested ending boundary.
	range.Collapse( isStart ) ;

	// Expands it to the block contents.
	range.Expand( 'block_contents' ) ;

	// Create the fixed block.
	var oFixedBlock = this.Window.document.createElement( blockTag ) ;

	// Move the contents of the temporary range to the fixed block.
	range.ExtractContents().AppendTo( oFixedBlock ) ;
	FCKDomTools.TrimNode( oFixedBlock ) ;

	// Insert the fixed block into the DOM.
	range.InsertNode( oFixedBlock ) ;

	// Move the range back to the bookmarked place.
	range.MoveToBookmark( oBookmark ) ;
}

// Appends a bogus <br> at the end of the element, if not yet available.
FCKEnterKey.prototype._AppendBogusBr = function( element )
{
	if ( !element )
		return ;

	var eLastChild = FCKTools.GetLastItem( element.getElementsByTagName('br') ) ;

	if ( !eLastChild || eLastChild.getAttribute( 'type', 2 ) != '_moz' )
		element.appendChild( FCKTools.CreateBogusBR( this.Window.document ) ) ;
}

// Recreate the elements tree at the end of the source block, at the beginning
// of the target block. Eg.:
//	If source = <p><u>Some</u> sample <b><i>text</i></b></p> then target = <p><b><i></i></b></p>
//	If source = <p><u>Some</u> sample text</p> then target = <p></p>
FCKEnterKey.prototype._RecreateEndingTree = function( source, target )
{
	while ( ( source = source.lastChild ) && source.nodeType == 1 && FCKListsLib.InlineChildReqElements[ source.nodeName.toLowerCase() ] != null )
		target = target.insertBefore( source.cloneNode( false ), target.firstChild ) ;
}

// Outdents a LI, maintaining the seletion defined on a range.
FCKEnterKey.prototype._OutdentWithSelection = function( li, range )
{
	var oBookmark = range.CreateBookmark() ;

	FCKListHandler.OutdentListItem( li ) ;

	range.MoveToBookmark( oBookmark ) ;
	range.Select() ;
}