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/*
 [The "BSD licence"]
 Copyright (c) 2005-2008 Terence Parr
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:
 1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
 2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.
 3. The name of the author may not be used to endorse or promote products
    derived from this software without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.antlr.runtime.tree;

import org.antlr.runtime.*;

public class TreeParser extends BaseRecognizer {
        public static final int DOWN = Token.DOWN;
        public static final int UP = Token.UP;

        protected TreeNodeStream input;

        public TreeParser(TreeNodeStream input) {
                super(); // highlight that we go to super to set state object
                setTreeNodeStream(input);
        }

        public TreeParser(TreeNodeStream input, RecognizerSharedState state) {
                super(state); // share the state object with another parser
                setTreeNodeStream(input);
    }

        public void reset() {
                super.reset(); // reset all recognizer state variables
                if ( input!=null ) {
                        input.seek(0); // rewind the input
                }
        }

        public void setTreeNodeStream(TreeNodeStream input) {
                this.input = input;
        }

        public TreeNodeStream getTreeNodeStream() {
                return input;
        }

        public String getSourceName() {
                return input.getSourceName();
        }

        protected Object getCurrentInputSymbol(IntStream input) {
                return ((TreeNodeStream)input).LT(1);
        }

        protected Object getMissingSymbol(IntStream input,
                                                                          RecognitionException e,
                                                                          int expectedTokenType,
                                                                          BitSet follow)
        {
                String tokenText =
                        "<missing "+getTokenNames()[expectedTokenType]+">";
                return new CommonTree(new CommonToken(expectedTokenType, tokenText));
        }       

        public void matchAny(IntStream ignore) { // ignore stream, copy of input
                state.errorRecovery = false;
                state.failed = false;
                Object look = input.LT(1);
                if ( input.getTreeAdaptor().getChildCount(look)==0 ) {
                        input.consume(); // not subtree, consume 1 node and return
                        return;
                }
                // current node is a subtree, skip to corresponding UP.
                // must count nesting level to get right UP
                int level=0;
                int tokenType = input.getTreeAdaptor().getType(look);
                while ( tokenType!=Token.EOF && !(tokenType==UP && level==0) ) {
                        input.consume();
                        look = input.LT(1);
                        tokenType = input.getTreeAdaptor().getType(look);
                        if ( tokenType == DOWN ) {
                                level++;
                        }
                        else if ( tokenType == UP ) {
                                level--;
                        }
                }
                input.consume(); // consume UP
        }

        protected void mismatch(IntStream input, int ttype, BitSet follow)
                throws RecognitionException
        {
                throw new MismatchedTreeNodeException(ttype, (TreeNodeStream)input);
        }

        public String getErrorHeader(RecognitionException e) {
                return getGrammarFileName()+": node from "+
                           (e.approximateLineInfo?"after ":"")+"line "+e.line+":"+e.charPositionInLine;
        }

        public String getErrorMessage(RecognitionException e, String[] tokenNames) {
                if ( this instanceof TreeParser ) {
                        TreeAdaptor adaptor = ((TreeNodeStream)e.input).getTreeAdaptor();
                        e.token = adaptor.getToken(e.node);
                        if ( e.token==null ) { // could be an UP/DOWN node
                                e.token = new CommonToken(adaptor.getType(e.node),
                                                                                  adaptor.getText(e.node));
                        }
                }
                return super.getErrorMessage(e, tokenNames);
        }

        public void traceIn(String ruleName, int ruleIndex)  {
                super.traceIn(ruleName, ruleIndex, input.LT(1));
        }

        public void traceOut(String ruleName, int ruleIndex)  {
                super.traceOut(ruleName, ruleIndex, input.LT(1));
        }

}

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