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/*
 [The "BSD license"]
 Copyright (c) 2005-2009 Terence Parr
 All rights reserved.

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 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,
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package org.antlr.runtime.tree;

import org.antlr.runtime.Token;
import org.antlr.runtime.TokenStream;
import org.antlr.runtime.RecognitionException;

import java.util.HashMap;
import java.util.Map;

public abstract class BaseTreeAdaptor implements TreeAdaptor {
        protected Map treeToUniqueIDMap;
        protected int uniqueNodeID = 1;

        public Object nil() {
                return create(null);
        }

        public Object errorNode(TokenStream input, Token start, Token stop,
                                                        RecognitionException e)
        {
                CommonErrorNode t = new CommonErrorNode(input, start, stop, e);
                //System.out.println("returning error node '"+t+"' @index="+input.index());
                return t;
        }

        public boolean isNil(Object tree) {
                return ((Tree)tree).isNil();
        }

        public Object dupTree(Object tree) {
                return dupTree(tree, null);
        }

        public Object dupTree(Object t, Object parent) {
                if ( t==null ) {
                        return null;
                }
                Object newTree = dupNode(t);
                // ensure new subtree root has parent/child index set
                setChildIndex(newTree, getChildIndex(t)); // same index in new tree
                setParent(newTree, parent);
                int n = getChildCount(t);
                for (int i = 0; i < n; i++) {
                        Object child = getChild(t, i);
                        Object newSubTree = dupTree(child, t);
                        addChild(newTree, newSubTree);
                }
                return newTree;
        }

        public void addChild(Object t, Object child) {
                if ( t!=null && child!=null ) {
                        ((Tree)t).addChild((Tree)child);
                }
        }

        public Object becomeRoot(Object newRoot, Object oldRoot) {
        //System.out.println("becomeroot new "+newRoot.toString()+" old "+oldRoot);
        Tree newRootTree = (Tree)newRoot;
                Tree oldRootTree = (Tree)oldRoot;
                if ( oldRoot==null ) {
                        return newRoot;
                }
                // handle ^(nil real-node)
                if ( newRootTree.isNil() ) {
            int nc = newRootTree.getChildCount();
            if ( nc==1 ) newRootTree = (Tree)newRootTree.getChild(0);
            else if ( nc >1 ) {
                                // TODO: make tree run time exceptions hierarchy
                                throw new RuntimeException("more than one node as root (TODO: make exception hierarchy)");
                        }
        }
                // add oldRoot to newRoot; addChild takes care of case where oldRoot
                // is a flat list (i.e., nil-rooted tree).  All children of oldRoot
                // are added to newRoot.
                newRootTree.addChild(oldRootTree);
                return newRootTree;
        }

        public Object rulePostProcessing(Object root) {
                //System.out.println("rulePostProcessing: "+((Tree)root).toStringTree());
                Tree r = (Tree)root;
                if ( r!=null && r.isNil() ) {
                        if ( r.getChildCount()==0 ) {
                                r = null;
                        }
                        else if ( r.getChildCount()==1 ) {
                                r = (Tree)r.getChild(0);
                                // whoever invokes rule will set parent and child index
                                r.setParent(null);
                                r.setChildIndex(-1);
                        }
                }
                return r;
        }

        public Object becomeRoot(Token newRoot, Object oldRoot) {
                return becomeRoot(create(newRoot), oldRoot);
        }

        public Object create(int tokenType, Token fromToken) {
                fromToken = createToken(fromToken);
                //((ClassicToken)fromToken).setType(tokenType);
                fromToken.setType(tokenType);
                Tree t = (Tree)create(fromToken);
                return t;
        }

        public Object create(int tokenType, Token fromToken, String text) {
        if (fromToken == null) return create(tokenType, text);
                fromToken = createToken(fromToken);
                fromToken.setType(tokenType);
                fromToken.setText(text);
                Tree t = (Tree)create(fromToken);
                return t;
        }

        public Object create(int tokenType, String text) {
                Token fromToken = createToken(tokenType, text);
                Tree t = (Tree)create(fromToken);
                return t;
        }

        public int getType(Object t) {
                return ((Tree)t).getType();
        }

        public void setType(Object t, int type) {
                throw new NoSuchMethodError("don't know enough about Tree node");
        }

        public String getText(Object t) {
                return ((Tree)t).getText();
        }

        public void setText(Object t, String text) {
                throw new NoSuchMethodError("don't know enough about Tree node");
        }

        public Object getChild(Object t, int i) {
                return ((Tree)t).getChild(i);
        }

        public void setChild(Object t, int i, Object child) {
                ((Tree)t).setChild(i, (Tree)child);
        }

        public Object deleteChild(Object t, int i) {
                return ((Tree)t).deleteChild(i);
        }

        public int getChildCount(Object t) {
                return ((Tree)t).getChildCount();
        }

        public int getUniqueID(Object node) {
                if ( treeToUniqueIDMap==null ) {
                         treeToUniqueIDMap = new HashMap();
                }
                Integer prevID = (Integer)treeToUniqueIDMap.get(node);
                if ( prevID!=null ) {
                        return prevID.intValue();
                }
                int ID = uniqueNodeID;
                treeToUniqueIDMap.put(node, new Integer(ID));
                uniqueNodeID++;
                return ID;
                // GC makes these nonunique:
                // return System.identityHashCode(node);
        }

        public abstract Token createToken(int tokenType, String text);

        public abstract Token createToken(Token fromToken);
}

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