(function(){
	var ns = __namespace( "Components.Vim.Actions" );

	/** @type {System.Debug} */
	var debug                                 = __import( "System.Debug" );
	var beep = __import( "Components.Vim.Beep" );

	/** @type {Components.Vim.State.Stack} */
	var Stack                                  = __import( "Components.Vim.State.Stack" );

	var VimError = __import( "Components.Vim.Error" );
	var Mesg = __import( "Components.Vim.Message" );

	var occurence = __import( "System.utils.Perf.CountSubstr" );

	var REPL_BEFORE = 0;
	var REPL_OFFSET = 1;
	var REPL_LENGTH = 2;

	/** @type {Components.Vim.IAction}
	 *  Cursor @param {Components.Vim.Cursor}
	 *  e @param {Components.Vim.ActionEvent}
	 **/
	var SHIFT_LINES = function( Cursor, e )
	{
		/** @type {Components.Vim.Cursor} */
		this.__cursor = Cursor;
		this.__startX = Cursor.aPos;
		this.__msg = "<LINE_SHIFT>";

		this.__slineNum = Cursor.getLine().lineNum;

		this.__lines = e.count;
		debug.Info( "Open shift: " + this.__lines + " line(s) below the cursor" );

		this.__direction = e.kMap( ">" ) ? 1 : -1;
		debug.Info( "Direction is: " + ( this.__direction == 1 ? ">" : "<" ) );

		Cursor.suppressEvent();
	};

	SHIFT_LINES.prototype.allowMovement = true;

	SHIFT_LINES.prototype.dispose = function()
	{
		this.__cursor.unsuppressEvent();
	};

	SHIFT_LINES.prototype.handler = function( e, sp )
	{
		e.preventDefault();

		if( e.ModKeys || e.kMap( "i" ) ) return;

		var cur = this.__cursor;
		var feeder = cur.feeder;

		var Triggered = false;
		var dir = this.__direction;

		var start = this.__slineNum;
		var nline = this.__lines;

		if( 1 < e.count )
		{
			nline += e.count;
		}

		var end = start;

		var shiftCount = 1;
		if( sp == undefined )
		{
			Triggered = true;

			sp = this.__startX;

			var currAp = cur.aPos;

			if( this.__startX != currAp )
			{
				if( e.kMap( "h" ) || e.kMap( "l" ) ){}
				else if( e.kMap( "j" ) )
				{
					end = start + nline;
				}
				else if( e.kMap( "k" ) )
				{
					start -= nline;
				}
				else // TODO: Dectect movement line count
				{
				}
			}
			else
			{
				if( !( ( 0 < dir && ( e.kMap( ">" ) || e.kMap( "l" ) ) )
					|| ( dir < 0 && ( e.kMap( "<" ) || e.kMap( "h" ) ) )
				) )
				{
					beep();
					return true;
				}
			}
		}

		// last "\n" padding
		var c = feeder.content.slice( 0, -1 );

		var indents = c.match( /^[\t ]+/gm );
		var indentChar = "\t";
		var tabwidth = feeder.firstBuffer.tabWidth;

		if( indents )
		{
			var l = indents.length - 1;

			if( 1 < l )
			{
				debug.Info( "Guessing the tabstop:" );
				var tabOccr = 0;
				var spOccr = 0;

				// Guess indent
				var tabStat = {};

				for( var i = 0; i < l; i ++ )
				{
					var ind = indents[ i ];
					var indNext = indents[ i + 1 ];
					tabOccr += occurence( ind, "\t" );
					spOccr += occurence( ind, " " );
					var d = indNext.length - ind.length;
					if( d == 0 ) continue;

					d = d < 0 ? -d : d;

					if( !tabStat[ d ] ) tabStat[ d ] = 0;

					tabStat[ d ] ++;
				}

				var upperDiff = 0;
				var indentCLen = 0;
				for( var i in tabStat )
				{
					var p = tabStat[ i ];
					if( upperDiff < p )
					{
						upperDiff = p;
						indentCLen = i;
					}
				}

				spOccr /= indentCLen;

				if( tabOccr < spOccr )
				{
					indentChar = "";
					for( var i = 0; i < indentCLen; i ++ ) indentChar += " ";
				}

				tabwidth = indentCLen;

				debug.Info( "\tTab count: " + tabOccr );
				debug.Info( "\tSpace count: " + spOccr );
				debug.Info( "\ti.e. indent using " + JSON.stringify( indentChar ) );
			}
			else
			{
				debug.Info( "Not enough tabs to determine the tabstop, using default" );
			}
		}

		debug.Info( "Start: " + start, "End: " + end );
		var rBlock = "";

		var started = false;
		var indentTimes = 1;

		feeder.content = "";
		nline = 0;

		for( var i = 0, j = 0; 0 <= i; i = c.indexOf( "\n", i ), j ++ )
		{
			i ++;

			if( j < start ) continue;
			else if( !started )
			{
				started = true;
				feeder.content = c.substring( 0, i - 1 );
			}

			if( end < j ) break;

			var line = c.substring( 1 < i ? i : i - 1, c.indexOf( "\n", i ) );

			if( 1 < i ) feeder.content += "\n";

			if( line !== "" )
			{
				if( 0 < dir )
				{
					feeder.content += indentChar + line;
				}
				else
				{
					for( var si = 0, sj = 1; si < indentTimes; si ++ )
					{
						var startC = line[ si ];
						if( startC == " " )
						{
							for( ; sj < tabwidth; sj ++ )
							{
								if( !~"\t ".indexOf( line[ si + sj ] ) ) break;
							}
						}
						else if( startC != "\t" ) break;
					}

					feeder.content += line.substring( si + sj - 1 );
				}
				nline ++;
			}
		}
 
		feeder.content += "\n" + c.substring( i ) + "\n";
		feeder.pan();

		this.__msg = Mesg( "LINES_SHIFTED", nline, dir < 0 ? "<" : ">", 1 );

		return Triggered;
	};

	SHIFT_LINES.prototype.getMessage = function()
	{
		return this.__msg;
	};

	ns[ NS_EXPORT ]( EX_CLASS, "SHIFT_LINES", SHIFT_LINES );
})();