using System;
using Stream			= System.IO.Stream;
using TextReader		= System.IO.TextReader;
using StringBuilder		= System.Text.StringBuilder;
using Hashtable			= System.Collections.Hashtable;
using Assembly			= System.Reflection.Assembly;
using EventHandlerList	= System.ComponentModel.EventHandlerList;

using BitSet			= antlr.collections.impl.BitSet;
using antlr.debug;

namespace antlr
{
	/*ANTLR Translator Generator
	* Project led by Terence Parr at http://www.jGuru.com
	* Software rights: http://www.antlr.org/license.html
	*
	* $Id:$
	*/

	//
	// ANTLR C# Code Generator by Micheal Jordan
	//                            Kunle Odutola       : kunle UNDERSCORE odutola AT hotmail DOT com
	//                            Anthony Oguntimehin
	//
	// With many thanks to Eric V. Smith from the ANTLR list.
	//
	
	public abstract class CharScanner : TokenStream, ICharScannerDebugSubject
	{
		internal const char NO_CHAR = (char) (0);
		public static readonly char EOF_CHAR = Char.MaxValue;

		// Used to store event delegates
		private EventHandlerList events_ = new EventHandlerList();

		protected internal EventHandlerList Events 
		{
			get	{ return events_;	}
		}

		// The unique keys for each event that CharScanner [objects] can generate
		internal static readonly object EnterRuleEventKey			= new object();
		internal static readonly object ExitRuleEventKey			= new object();
		internal static readonly object DoneEventKey				= new object();
		internal static readonly object ReportErrorEventKey			= new object();
		internal static readonly object ReportWarningEventKey		= new object();
		internal static readonly object NewLineEventKey				= new object();
		internal static readonly object MatchEventKey				= new object();
		internal static readonly object MatchNotEventKey			= new object();
		internal static readonly object MisMatchEventKey			= new object();
		internal static readonly object MisMatchNotEventKey			= new object();
		internal static readonly object ConsumeEventKey				= new object();
		internal static readonly object LAEventKey					= new object();
		internal static readonly object SemPredEvaluatedEventKey	= new object();
		internal static readonly object SynPredStartedEventKey		= new object();
		internal static readonly object SynPredFailedEventKey		= new object();
		internal static readonly object SynPredSucceededEventKey	= new object();

		protected internal StringBuilder text;				// text of current token
		
		protected bool saveConsumedInput = true;	// does consume() save characters?

		/// <summary>Used for creating Token instances.</summary>
		protected TokenCreator	tokenCreator;

		/// <summary>Used for caching lookahead characters.</summary>
		protected char			cached_LA1;
		protected char			cached_LA2;

		protected bool caseSensitive = true;
		protected bool caseSensitiveLiterals = true;
		protected Hashtable literals; // set by subclass
		
		/*Tab chars are handled by tab() according to this value; override
		*  method to do anything weird with tabs.
		*/
		protected internal int tabsize = 8;
		
		protected internal IToken returnToken_ = null; // used to return tokens w/o using return val.
		
		protected internal LexerSharedInputState inputState;
		
		/*Used during filter mode to indicate that path is desired.
		*  A subsequent scan error will report an error as usual if
		*  acceptPath=true;
		*/
		protected internal bool commitToPath = false;
		
		/*Used to keep track of indentdepth for traceIn/Out */
		protected internal int traceDepth = 0;
		
		public CharScanner()
		{
			text = new StringBuilder();
			setTokenCreator(new CommonToken.CommonTokenCreator());
		}
		
		public CharScanner(InputBuffer cb) : this()
		{
			inputState = new LexerSharedInputState(cb);
			cached_LA2 = inputState.input.LA(2);
			cached_LA1 = inputState.input.LA(1);
		}
		
		public CharScanner(LexerSharedInputState sharedState) : this()
		{
			inputState = sharedState;
			if (inputState != null)
			{
				cached_LA2 = inputState.input.LA(2);
				cached_LA1 = inputState.input.LA(1);
		}
	}
		

		public event TraceEventHandler EnterRule
		{
			add		{	Events.AddHandler(EnterRuleEventKey, value);	}
			remove	{	Events.RemoveHandler(EnterRuleEventKey, value);	}
		}

		public event TraceEventHandler ExitRule
		{
			add		{	Events.AddHandler(ExitRuleEventKey, value);		}
			remove	{	Events.RemoveHandler(ExitRuleEventKey, value);	}
		}

		public event TraceEventHandler Done
		{
			add		{	Events.AddHandler(DoneEventKey, value);		}
			remove	{	Events.RemoveHandler(DoneEventKey, value);	}
		}

		public event MessageEventHandler ErrorReported
		{
			add		{	Events.AddHandler(ReportErrorEventKey, value);		}
			remove	{	Events.RemoveHandler(ReportErrorEventKey, value);	}
		}

		public event MessageEventHandler WarningReported
		{
			add		{	Events.AddHandler(ReportWarningEventKey, value);	}
			remove	{	Events.RemoveHandler(ReportWarningEventKey, value);	}
		}

		public event NewLineEventHandler HitNewLine
		{
			add		{	Events.AddHandler(NewLineEventKey, value);		}
			remove	{	Events.RemoveHandler(NewLineEventKey, value);	}
		}

		public event MatchEventHandler MatchedChar
		{
			add		{	Events.AddHandler(MatchEventKey, value);	}
			remove	{	Events.RemoveHandler(MatchEventKey, value);	}
		}

		public event MatchEventHandler MatchedNotChar
		{
			add		{	Events.AddHandler(MatchNotEventKey, value);		}
			remove	{	Events.RemoveHandler(MatchNotEventKey, value);	}
		}

		public event MatchEventHandler MisMatchedChar
		{
			add		{	Events.AddHandler(MisMatchEventKey, value);		}
			remove	{	Events.RemoveHandler(MisMatchEventKey, value);	}
		}

		public event MatchEventHandler MisMatchedNotChar
		{
			add		{	Events.AddHandler(MisMatchNotEventKey, value);		}
			remove	{	Events.RemoveHandler(MisMatchNotEventKey, value);	}
		}

		public event TokenEventHandler ConsumedChar
		{
			add		{	Events.AddHandler(ConsumeEventKey, value);		}
			remove	{	Events.RemoveHandler(ConsumeEventKey, value);	}
		}

		public event TokenEventHandler CharLA
		{
			add		{	Events.AddHandler(LAEventKey, value);		}
			remove	{	Events.RemoveHandler(LAEventKey, value);	}
		}

		public event SemanticPredicateEventHandler SemPredEvaluated
		{
			add		{	Events.AddHandler(SemPredEvaluatedEventKey, value);		}
			remove	{	Events.RemoveHandler(SemPredEvaluatedEventKey, value);	}
		}

		public event SyntacticPredicateEventHandler SynPredStarted
		{
			add		{	Events.AddHandler(SynPredStartedEventKey, value);		}
			remove	{	Events.RemoveHandler(SynPredStartedEventKey, value);	}
		}

		public event SyntacticPredicateEventHandler SynPredFailed
		{
			add		{	Events.AddHandler(SynPredFailedEventKey, value);	}
			remove	{	Events.RemoveHandler(SynPredFailedEventKey, value);	}
		}

		public event SyntacticPredicateEventHandler SynPredSucceeded
		{
			add		{	Events.AddHandler(SynPredSucceededEventKey, value);		}
			remove	{	Events.RemoveHandler(SynPredSucceededEventKey, value);	}
		}

		// From interface TokenStream
		public virtual IToken nextToken() { return null; }

		public virtual void  append(char c)
		{
			if (saveConsumedInput)
			{
				text.Append(c);
			}
		}
		
		public virtual void  append(string s)
		{
			if (saveConsumedInput)
			{
				text.Append(s);
			}
		}
		
		public virtual void  commit()
		{
			inputState.input.commit();
		}
		
		public virtual void  consume()
		{
			if (inputState.guessing == 0)
			{
				if (caseSensitive)
				{
					append(cached_LA1);
				}
				else
				{
					// use input.LA(), not LA(), to get original case
					// CharScanner.LA() would toLower it.
					append(inputState.input.LA(1));
				}
				if (cached_LA1 == '\t')
				{
					tab();
				}
				else
				{
					inputState.column++;
				}
			}
			if (caseSensitive)
			{
				cached_LA1 = inputState.input.consume();
				cached_LA2 = inputState.input.LA(2);
			}
			else
			{
				cached_LA1 = toLower(inputState.input.consume());
				cached_LA2 = toLower(inputState.input.LA(2));
			}
		}
		
		/*Consume chars until one matches the given char */
		public virtual void  consumeUntil(int c)
		{
			while ((EOF_CHAR != cached_LA1) && (c != cached_LA1))
			{
				consume();
			}
		}
		
		/*Consume chars until one matches the given set */
		public virtual void  consumeUntil(BitSet bset)
		{
			while (cached_LA1 != EOF_CHAR && !bset.member(cached_LA1))
			{
				consume();
			}
		}
		
		public virtual bool getCaseSensitive()
		{
			return caseSensitive;
		}
		
		public bool getCaseSensitiveLiterals()
		{
			return caseSensitiveLiterals;
		}
		
		public virtual int getColumn()
		{
			return inputState.column;
		}
		
		public virtual void  setColumn(int c)
		{
			inputState.column = c;
		}
		
		public virtual bool getCommitToPath()
		{
			return commitToPath;
		}
		
		public virtual string getFilename()
		{
			return inputState.filename;
		}
		
		public virtual InputBuffer getInputBuffer()
		{
			return inputState.input;
		}
		
		public virtual LexerSharedInputState getInputState()
		{
			return inputState;
		}
		
		public virtual void  setInputState(LexerSharedInputState state)
		{
			inputState = state;
		}
		
		public virtual int getLine()
		{
			return inputState.line;
		}
		
		/*return a copy of the current text buffer */
		public virtual string getText()
		{
			return text.ToString();
		}
		
		public virtual IToken getTokenObject()
		{
			return returnToken_;
		}
		
		public virtual char LA(int i)
		{
			if (i == 1)
			{
				return cached_LA1;
			}
			if (i == 2)
			{
				return cached_LA2;
			}
			if (caseSensitive)
			{
				return inputState.input.LA(i);
			}
			else
			{
				return toLower(inputState.input.LA(i));
			}
		}
		
		protected internal virtual IToken makeToken(int t)
		{
			IToken	newToken	= null;
			bool	typeCreated;

			try
			{
				newToken = tokenCreator.Create();
				if (newToken != null)
				{
					newToken.Type = t;
					newToken.setColumn(inputState.tokenStartColumn);
					newToken.setLine(inputState.tokenStartLine);
					// tracking real start line now: newToken.setLine(inputState.line);
					newToken.setFilename(inputState.filename);
				}
				typeCreated	= true;
			}
			catch
			{
				typeCreated = false;
			}

			if (!typeCreated)
			{
				panic("Can't create Token object '" + tokenCreator.TokenTypeName + "'");
				newToken = Token.badToken;
			}
			return newToken;
		}
		
		public virtual int mark()
		{
			return inputState.input.mark();
		}
		
		public virtual void  match(char c)
		{
			match((int) c);
		}

		public virtual void  match(int c)
		{
			if (cached_LA1 != c)
			{
				throw new MismatchedCharException(cached_LA1, Convert.ToChar(c), false, this);
			}
			consume();
		}
		
		public virtual void  match(BitSet b)
		{
			if (!b.member(cached_LA1))
			{
				throw new MismatchedCharException(cached_LA1, b, false, this);
			}
			consume();
		}
		
		public virtual void  match(string s)
		{
			int len = s.Length;
			 for (int i = 0; i < len; i++)
			{
				if (cached_LA1 != s[i])
				{
					throw new MismatchedCharException(cached_LA1, s[i], false, this);
				}
				consume();
			}
		}
		
		public virtual void  matchNot(char c)
		{
			matchNot((int) c);
		}
		
		public virtual void  matchNot(int c)
		{
			if (cached_LA1 == c)
			{
				throw new MismatchedCharException(cached_LA1, Convert.ToChar(c), true, this);
			}
			consume();
		}
		
		public virtual void  matchRange(int c1, int c2)
		{
			if (cached_LA1 < c1 || cached_LA1 > c2)
			{
				throw new MismatchedCharException(cached_LA1, Convert.ToChar(c1), Convert.ToChar(c2), false, this);
			}
			consume();
		}
		
		public virtual void  matchRange(char c1, char c2)
		{
			matchRange((int) c1, (int) c2);
		}
		
		public virtual void  newline()
		{
			inputState.line++;
			inputState.column = 1;
		}
		
		/*advance the current column number by an appropriate amount
		*  according to tab size. This method is called from consume().
		*/
		public virtual void  tab()
		{
			int c = getColumn();
			int nc = (((c - 1) / tabsize) + 1) * tabsize + 1; // calculate tab stop
			setColumn(nc);
		}
		
		public virtual void  setTabSize(int size)
		{
			tabsize = size;
		}
		
		public virtual int getTabSize()
		{
			return tabsize;
		}
		
		public virtual void panic()
		{
			//Console.Error.WriteLine("CharScanner: panic");
			//Environment.Exit(1);
			panic("");

		}
		
		/// <summary>
		/// This method is executed by ANTLR internally when it detected an illegal
		/// state that cannot be recovered from.
		/// The previous implementation of this method called <see cref="Environment.Exit"/>
		/// and writes directly to <see cref="Console.Error"/>, which is usually not 
		/// appropriate when a translator is embedded into a larger application.
		/// </summary>
		/// <param name="s">Error message.</param>
		public virtual void panic(string s)
		{
			//Console.Error.WriteLine("CharScanner; panic: " + s);
			//Environment.Exit(1);
			throw new ANTLRPanicException("CharScanner::panic: " + s);
		}
		
		/*Parser error-reporting function can be overridden in subclass */
		public virtual void  reportError(RecognitionException ex)
		{
			Console.Error.WriteLine(ex);
		}
		
		/*Parser error-reporting function can be overridden in subclass */
		public virtual void  reportError(string s)
		{
			if (getFilename() == null)
			{
				Console.Error.WriteLine("error: " + s);
			}
			else
			{
				Console.Error.WriteLine(getFilename() + ": error: " + s);
			}
		}
		
		/*Parser warning-reporting function can be overridden in subclass */
		public virtual void  reportWarning(string s)
		{
			if (getFilename() == null)
			{
				Console.Error.WriteLine("warning: " + s);
			}
			else
			{
				Console.Error.WriteLine(getFilename() + ": warning: " + s);
			}
		}
		
		public virtual void refresh()
		{
			if (caseSensitive)
			{
				cached_LA2 = inputState.input.LA(2);
				cached_LA1 = inputState.input.LA(1);
			}
			else
			{
				cached_LA2 = toLower(inputState.input.LA(2));
				cached_LA1 = toLower(inputState.input.LA(1));
			}
		}

		public virtual void resetState(InputBuffer ib)
		{
			text.Length = 0;
			traceDepth = 0;
			inputState.resetInput(ib);
			refresh();
		}

		public void resetState(Stream s)
		{
			resetState(new ByteBuffer(s));
		}

		public void resetState(TextReader tr)
		{
			resetState(new CharBuffer(tr));
		}

		public virtual void  resetText()
		{
			text.Length = 0;
			inputState.tokenStartColumn = inputState.column;
			inputState.tokenStartLine = inputState.line;
		}
		
		public virtual void  rewind(int pos)
		{
			inputState.input.rewind(pos);
			//setColumn(inputState.tokenStartColumn);
			cached_LA2 = inputState.input.LA(2);
			cached_LA1 = inputState.input.LA(1);
		}
		
		public virtual void  setCaseSensitive(bool t)
		{
			caseSensitive = t;
			if (caseSensitive)
			{
				cached_LA2 = inputState.input.LA(2);
				cached_LA1 = inputState.input.LA(1);
			}
			else
			{
				cached_LA2 = toLower(inputState.input.LA(2));
				cached_LA1 = toLower(inputState.input.LA(1));
			}
		}
		
		public virtual void  setCommitToPath(bool commit)
		{
			commitToPath = commit;
		}
		
		public virtual void  setFilename(string f)
		{
			inputState.filename = f;
		}
		
		public virtual void  setLine(int line)
		{
			inputState.line = line;
		}
		
		public virtual void  setText(string s)
		{
			resetText();
			text.Append(s);
		}
		
		public virtual void  setTokenCreator(TokenCreator tokenCreator)
		{
			this.tokenCreator = tokenCreator;
		}
		
		// Test the token text against the literals table
		// Override this method to perform a different literals test
		public virtual int testLiteralsTable(int ttype)
		{
			string tokenText = text.ToString();

			if ( (tokenText == null) || (tokenText == string.Empty) )
				return ttype;
			else
			{
				object typeAsObject = literals[tokenText];
				return (typeAsObject == null) ? ttype : ((int) typeAsObject);
			}
		}
		
		/*Test the text passed in against the literals table
		* Override this method to perform a different literals test
		* This is used primarily when you want to test a portion of
		* a token.
		*/
		public virtual int testLiteralsTable(string someText, int ttype)
		{
			if ( (someText == null) || (someText == string.Empty) )
				return ttype;
			else
			{
				object typeAsObject = literals[someText];
				return (typeAsObject == null) ? ttype : ((int) typeAsObject);
			}
		}
		
		// Override this method to get more specific case handling
		public virtual char toLower(int c)
		{
			return Char.ToLower(Convert.ToChar(c), System.Globalization.CultureInfo.InvariantCulture);
		}
		
		public virtual void  traceIndent()
		{
			 for (int i = 0; i < traceDepth; i++)
				Console.Out.Write(" ");
		}
		
		public virtual void  traceIn(string rname)
		{
			traceDepth += 1;
			traceIndent();
			Console.Out.WriteLine("> lexer " + rname + "; c==" + LA(1));
		}
		
		public virtual void  traceOut(string rname)
		{
			traceIndent();
			Console.Out.WriteLine("< lexer " + rname + "; c==" + LA(1));
			traceDepth -= 1;
		}
		
		/*This method is called by YourLexer.nextToken() when the lexer has
		*  hit EOF condition.  EOF is NOT a character.
		*  This method is not called if EOF is reached during
		*  syntactic predicate evaluation or during evaluation
		*  of normal lexical rules, which presumably would be
		*  an IOException.  This traps the "normal" EOF condition.
		*
		*  uponEOF() is called after the complete evaluation of
		*  the previous token and only if your parser asks
		*  for another token beyond that last non-EOF token.
		*
		*  You might want to throw token or char stream exceptions
		*  like: "Heh, premature eof" or a retry stream exception
		*  ("I found the end of this file, go back to referencing file").
		*/
		public virtual void  uponEOF()
		{
		}

	}
}