using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace DynareTrimRedundantLocalVariables
{
	class Program
	{
		static void Main( string[ ] lasArgs )
		{
			if( lasArgs.Length == 0 )
			{
				Console.WriteLine( "Command line:\n\nDynareTrimRedundantLocalVariables inputfile.mod [outputfile.mod]\n" );
				return;
			}
			Console.WriteLine( "Starting." );
			Console.WriteLine( "Warning: Unnecessary local variables mentioned in comments will not be removed." );
			string lsInput = File.ReadAllText( lasArgs[ 0 ] );
			bool lbCutMade;
			do 
			{
				StringBuilder lOutput = new StringBuilder( );
				string[] lasInputLines = lsInput.Split( "\n\r".ToCharArray( ), StringSplitOptions.RemoveEmptyEntries );
				string[] lasInputTokens = lsInput.Split( "`¬!\"£$%^&*()-=+[]{};'#:@~\\|,./<>? \t\n\r".ToCharArray( ), StringSplitOptions.RemoveEmptyEntries );
				Dictionary< string, int > ldsnTokenOccurrences = new Dictionary< string, int >( );
				foreach( string lsToken in lasInputTokens )
				{
					if( ldsnTokenOccurrences.ContainsKey( lsToken ) ) ++ldsnTokenOccurrences[ lsToken ];
					else ldsnTokenOccurrences[ lsToken ] = 1;
				}

				string lsLineInfo = "";
				int lnTabDepth = 0;
				int lnSpaceDepth = 0;
				lbCutMade = false;

				foreach( string lsInputLine in lasInputLines )
				{
					string lsLine = lsInputLine.Trim( );
					if( lsLine.Length > 0 )
					{
						switch( lsLine[ 0 ] )
						{
						case '#':
							string lsTemp = lsLine.TrimStart( "# \t".ToCharArray( ) );
							string lsLocalVariableName = lsTemp.Remove( lsTemp.IndexOfAny( "= \t".ToCharArray( ) ) );
							if( ldsnTokenOccurrences[ lsLocalVariableName ] > 1 )
								goto default;
							else
								lbCutMade = true;
							break;
						case '@':
							lsLineInfo = lsLine.Substring( 2 );
							break;
						default:
							string lsComment = "";
							if( lsLineInfo.Length > 0 )
							{
								lsComment = "\t//\t" + lsLineInfo;
								lsLineInfo = "";
							}
							int lnNewTabDepth = 0;
							int lnNewSpaceDepth = 0;
							for( int i = 0; i < lsInputLine.Length; ++i )
							{
								if( lsInputLine[ i ] == '\t' )
									++lnNewTabDepth;
								else if( lsInputLine[ i ] == ' ' )
									++lnNewSpaceDepth;
								else
									break;
							}
							bool lbNewLineNeeded = lnNewTabDepth != lnTabDepth || lnNewSpaceDepth != lnSpaceDepth;
							lnTabDepth = lnNewTabDepth;
							lnSpaceDepth = lnNewSpaceDepth;
							lOutput.Append( lbNewLineNeeded ? "\n" : "" ).Append( lsInputLine ).Append( lsComment ).Append( "\n" );
							break;
						}
					}
				}
				lsInput = lOutput.ToString( );
				if( lbCutMade )
					Console.WriteLine( "Cut(s) made, rescanning." );
				else
					Console.WriteLine( "No cuts made, saving output." );
			} while ( lbCutMade );

			string lsOutputFileName;
			if( lasArgs.Length > 1 && lasArgs[ 1 ].Length > 0 )
				lsOutputFileName = lasArgs[ 1 ];
			else
				lsOutputFileName = lasArgs[ 0 ] + ".new.mod";
			File.WriteAllText( lsOutputFileName, lsInput );
			Console.WriteLine( "Done. Press any key to exit." );
			Console.ReadKey( );
		}
	}
}