/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.jsdt.internal.compiler.parser;

/**
 * Internal structure for parsing recovery 
 */
import org.eclipse.wst.jsdt.internal.compiler.ast.AbstractMethodDeclaration;
import org.eclipse.wst.jsdt.internal.compiler.ast.ASTNode;
import org.eclipse.wst.jsdt.internal.compiler.ast.Block;
import org.eclipse.wst.jsdt.internal.compiler.ast.FieldDeclaration;
import org.eclipse.wst.jsdt.internal.compiler.ast.ImportReference;
import org.eclipse.wst.jsdt.internal.compiler.ast.LocalDeclaration;
import org.eclipse.wst.jsdt.internal.compiler.ast.Statement;
import org.eclipse.wst.jsdt.internal.compiler.ast.TypeDeclaration;

public class RecoveredElement {

	public RecoveredElement parent;
	public int bracketBalance;
	public boolean foundOpeningBrace;
	protected Parser recoveringParser;
public RecoveredElement(RecoveredElement parent, int bracketBalance){
	this(parent, bracketBalance, null);
}
public RecoveredElement(RecoveredElement parent, int bracketBalance, Parser parser){
	this.parent = parent;
	this.bracketBalance = bracketBalance;
	this.recoveringParser = parser;
}
/*
 *	Record a method declaration
 */
public RecoveredElement add(AbstractMethodDeclaration methodDeclaration, int bracketBalanceValue) {

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(methodDeclaration.declarationSourceStart - 1));	
	return this.parent.add(methodDeclaration, bracketBalanceValue);
}
/*
 * Record a nested block declaration
 */
public RecoveredElement add(Block nestedBlockDeclaration, int bracketBalanceValue) {

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(nestedBlockDeclaration.sourceStart - 1));	
	return this.parent.add(nestedBlockDeclaration, bracketBalanceValue);
}
/*
 * Record a field declaration
 */
public RecoveredElement add(FieldDeclaration fieldDeclaration, int bracketBalanceValue) {

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(fieldDeclaration.declarationSourceStart - 1));	
	return this.parent.add(fieldDeclaration, bracketBalanceValue);
}
/*
 *	Record an import reference
 */
public RecoveredElement add(ImportReference importReference, int bracketBalanceValue){

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(importReference.declarationSourceStart - 1));	
	return this.parent.add(importReference, bracketBalanceValue);
}
/*
 * Record a local declaration
 */
public RecoveredElement add(LocalDeclaration localDeclaration, int bracketBalanceValue) {

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(localDeclaration.declarationSourceStart - 1));	
	return this.parent.add(localDeclaration, bracketBalanceValue);
}
/*
 * Record a statement
 */
public RecoveredElement add(Statement statement, int bracketBalanceValue) {

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(statement.sourceStart - 1));	
	return this.parent.add(statement, bracketBalanceValue);
}
/*
 *	Record a type declaration
 */
public RecoveredElement add(TypeDeclaration typeDeclaration, int bracketBalanceValue){

	/* default behavior is to delegate recording to parent if any */
	if (this.parent == null) return this; // ignore
	this.updateSourceEndIfNecessary(this.previousAvailableLineEnd(typeDeclaration.declarationSourceStart - 1));	
	return this.parent.add(typeDeclaration, bracketBalanceValue);
}
/*
 * Answer the depth of this element, considering the parent link.
 */
public int depth(){
	int depth = 0;
	RecoveredElement current = this;
	while ((current = current.parent) != null) depth++;
	return depth;
}
/*
 * Answer the enclosing method node, or null if none
 */
public RecoveredInitializer enclosingInitializer(){
	RecoveredElement current = this;
	while (current != null){
		if (current instanceof RecoveredInitializer){
			return (RecoveredInitializer) current;
		}
		current = current.parent;
	}
	return null;
}
/*
 * Answer the enclosing method node, or null if none
 */
public RecoveredMethod enclosingMethod(){
	RecoveredElement current = this;
	while (current != null){
		if (current instanceof RecoveredMethod){
			return (RecoveredMethod) current;
		}
		current = current.parent;
	}
	return null;
}
/*
 * Answer the enclosing type node, or null if none
 */
public RecoveredType enclosingType(){
	RecoveredElement current = this;
	while (current != null){
		if (current instanceof RecoveredType){
			return (RecoveredType) current;
		}
		current = current.parent;
	}
	return null;
}
/*
 * Answer the closest specified parser
 */
public Parser parser(){
	RecoveredElement current = this;
	while (current != null){
		if (current.recoveringParser != null){
			return current.recoveringParser;
		}
		current = current.parent;
	}
	return null;
}
/* 
 * Answer the associated parsed structure
 */
public ASTNode parseTree(){
	return null;
}
/*
 * Iterate the enclosing blocks and tag them so as to preserve their content
 */
public void preserveEnclosingBlocks(){
	RecoveredElement current = this;
	while (current != null){
		if (current instanceof RecoveredBlock){
			((RecoveredBlock)current).preserveContent = true;
		}
		if (current instanceof RecoveredType){ // for anonymous types
			((RecoveredType)current).preserveContent = true;
		}
		current = current.parent;
	}
}
/*
 * Answer the position of the previous line end if
 * there is nothing but spaces in between it and the
 * line end. Used to trim spaces on unclosed elements.
 */
public int previousAvailableLineEnd(int position){

	Parser parser = this.parser();
	if (parser == null) return position;
	
	Scanner scanner = parser.scanner;
	if (scanner.lineEnds == null) return position;
	
	int index = scanner.getLineNumber(position);
	if (index < 2) return position;
	int previousLineEnd = scanner.lineEnds[index-2];

	char[] source = scanner.source;
	for (int i = previousLineEnd+1; i < position; i++){
		if (!(source[i] == ' ' || source[i] == '\t')) return position;
	}
	return previousLineEnd;
}
/*
 * Answer the very source end of the corresponding parse node
 */
public int sourceEnd(){
	return 0;
}
protected String tabString(int tab) {
	StringBuffer result = new StringBuffer();
	for (int i = tab; i > 0; i--) {
		result.append("  "); //$NON-NLS-1$
	}
	return result.toString();
}
/*
 * Answer the top node
 */
public RecoveredElement topElement(){
	RecoveredElement current = this;
	while (current.parent != null){
		current = current.parent;
	}
	return current;
}
public String toString() {
	return toString(0);
}
public String toString(int tab) {
	return super.toString();
}
/*
 * Answer the enclosing type node, or null if none
 */
public RecoveredType type(){
	RecoveredElement current = this;
	while (current != null){
		if (current instanceof RecoveredType){
			return (RecoveredType) current;
		}
		current = current.parent;
	}
	return null;
}
/*
 * Update the bodyStart of the corresponding parse node
 */
public void updateBodyStart(int bodyStart){
	this.foundOpeningBrace = true;	
}
/*
 * Update the corresponding parse node from parser state which
 * is about to disappear because of restarting recovery
 */
public void updateFromParserState(){
	// default implementation: do nothing
}
/*
 * A closing brace got consumed, might have closed the current element,
 * in which case both the currentElement is exited
 */
public RecoveredElement updateOnClosingBrace(int braceStart, int braceEnd){
	if ((--this.bracketBalance <= 0) && (this.parent != null)){
		this.updateSourceEndIfNecessary(braceStart, braceEnd);
		return this.parent;
	}
	return this;
}
/*
 * An opening brace got consumed, might be the expected opening one of the current element,
 * in which case the bodyStart is updated.
 */
/*public RecoveredElement updateOnOpeningBrace(int braceEnd){return null;}*/
public RecoveredElement updateOnOpeningBrace(int braceStart, int braceEnd){

	if (this.bracketBalance++ == 0){
		this.updateBodyStart(braceEnd + 1);
		return this;
	}
	return null; // no update is necessary
}
/*
 * Final update the corresponding parse node
 */
public void updateParseTree(){
	// default implementation: do nothing
}
/*
 * Update the declarationSourceEnd of the corresponding parse node
 */
public void updateSourceEndIfNecessary(int braceStart, int braceEnd){
	// default implementation: do nothing
}
public void updateSourceEndIfNecessary(int sourceEnd){
	this.updateSourceEndIfNecessary(sourceEnd + 1, sourceEnd);
}
}
