/*******************************************************************************
 * Copyright (c) 2000, 2003 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.jdt.core.dom;

import org.eclipse.jdt.internal.compiler.ast.AstNode;
import org.eclipse.jdt.internal.compiler.lookup.BlockScope;

/**
 * A binding resolver is an internal mechanism for figuring out the binding
 * for a major declaration, type, or name reference.
 * <p>
 * The default implementation serves as the default binding resolver
 * that does no resolving whatsoever. Internal subclasses do all the real work.
 * </p>
 * 
 * @see AST#getBindingResolver
 */
class BindingResolver {
	
	protected long modificationCount;
	/**
	 * Creates a binding resolver.
	 */
	BindingResolver() {
	}

	/**
	 * Store the number of modifications done using the ast. This is used to validate
	 * resolveBinding methods. If the number changed, all resolve bindings methods
	 * simply return null.
	 */
	protected void storeModificationCount(long modificationCount) {
		this.modificationCount = modificationCount;
	}
	
	/**
	 * Allows the user to store information about the given old/new pair of
	 * AST nodes.
	 * <p>
	 * The default implementation of this method does nothing.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param newNode the new AST node
	 * @param oldNode the old AST node
	 */
	void store(ASTNode newNode, AstNode oldASTNode) {
	}

	/**
	 * Resolves the given name and returns the type binding for it.
	 * <p>
	 * The implementation of <code>Name.resolveBinding</code> forwards to
	 * this method. How the name resolves is often a function of the context
	 * in which the name node is embedded as well as the name itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param name the name of interest
	 * @return the binding for the name, or <code>null</code> if no binding is
	 *    available
	 */
	IBinding resolveName(Name name) {
		return null;
	}

	/**
	 * Resolves the given type and returns the type binding for it.
	 * <p>
	 * The implementation of <code>Type.resolveBinding</code>
	 * forwards to this method. How the type resolves is often a function
	 * of the context in which the type node is embedded as well as the type
	 * subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param type the type of interest
	 * @return the binding for the given type, or <code>null</code>
	 *    if no binding is available 
	 */
	ITypeBinding resolveType(Type type) {
		return null;
	}

	/**
	 * Resolves the given well known type by name and returns the type binding
	 * for it.
	 * <p>
	 * The implementation of <code>ASTNode.resolveWellKnownType</code>
	 * forwards to this method.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param name the name of a well known type
	 * @return the corresponding type binding, or <code>null<code> if the 
	 *   named type is not considered well known or if no binding can be found
	 *   for it
	 */
	ITypeBinding resolveWellKnownType(String name) {
		return null;
	}

	/**
	 * Resolves the given class or interface declaration and returns the binding
	 * for it.
	 * <p>
	 * The implementation of <code>TypeDeclaration.resolveBinding</code> 
	 * (and <code>TypeDeclarationStatement.resolveBinding</code>) forwards
	 * to this method. How the type declaration resolves is often a function of
	 * the context in which the type declaration node is embedded as well as the
	 * type declaration subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param type the class or interface declaration of interest
	 * @return the binding for the given type declaration, or <code>null</code>
	 *    if no binding is available
	 */
	ITypeBinding resolveType(TypeDeclaration type) {
		return null;
	}
	
	/**
	 * Resolves the given anonymous class declaration and returns the binding
	 * for it.
	 * <p>
	 * The implementation of <code>AnonymousClassDeclaration.resolveBinding</code> 
	 * forwards to this method. How the declaration resolves is often a 
	 * function of the context in which the declaration node is embedded as well
	 * as the declaration subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param type the anonymous class declaration of interest
	 * @return the binding for the given class declaration, or <code>null</code>
	 *    if no binding is available
	 */
	ITypeBinding resolveType(AnonymousClassDeclaration type) {
		return null;
	}
	
	/**
	 * Resolves the given method declaration and returns the binding for it.
	 * <p>
	 * The implementation of <code>MethodDeclaration.resolveBinding</code>
	 * forwards to this method. How the method resolves is often a function of
	 * the context in which the method declaration node is embedded as well as
	 * the method declaration subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param method the method or constructor declaration of interest
	 * @return the binding for the given method declaration, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveMethod(MethodDeclaration method) {
		return null;
	}
	/**
	 * Resolves the given method invocation and returns the binding for it.
	 * <p>
	 * The implementation of <code>MethodInvocation.resolveMethodBinding</code>
	 * forwards to this method. How the method resolves is often a function of
	 * the context in which the method invocation node is embedded as well as
	 * the method invocation subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param method the method invocation of interest
	 * @return the binding for the given method invocation, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveMethod(MethodInvocation method) {
		return null;
	}
	/**
	 * Resolves the given method invocation and returns the binding for it.
	 * <p>
	 * The implementation of <code>MethodInvocation.resolveMethodBinding</code>
	 * forwards to this method. How the method resolves is often a function of
	 * the context in which the method invocation node is embedded as well as
	 * the method invocation subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param method the method invocation of interest
	 * @return the binding for the given method invocation, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveMethod(SuperMethodInvocation method) {
		return null;
	}	
	/**
	 * Resolves the given variable declaration and returns the binding for it.
	 * <p>
	 * The implementation of <code>VariableDeclaration.resolveBinding</code>
	 * forwards to this method. How the variable declaration resolves is often
	 * a function of the context in which the variable declaration node is 
	 * embedded as well as the variable declaration subtree itself. VariableDeclaration 
	 * declarations used as local variable, formal parameter and exception 
	 * variables resolve to local variable bindings; variable declarations
	 * used to declare fields resolve to field bindings.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param variable the variable declaration of interest
	 * @return the binding for the given variable declaration, or 
	 *    <code>null</code> if no binding is available
	 */
	IVariableBinding resolveVariable(VariableDeclaration variable) {
		return null;
	}

	/**
	 * Resolves the given field declaration and returns the binding for it.
	 * <p>
	 * The implementation of <code>FieldDeclaration.resolveBinding</code>
	 * forwards to this method. How the field declaration resolves is often
	 * a function of the context in which the variable declaration node is 
	 * embedded as well as the variable declaration subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param variable the field declaration of interest
	 * @return the binding for the given field declaration, or 
	 *    <code>null</code> if no binding is available
	 */
	IVariableBinding resolveVariable(FieldDeclaration variable) {
		return null;
	}
		
	/**
	 * Resolves the type of the given expression and returns the type binding
	 * for it. 
	 * <p>
	 * The implementation of <code>Expression.resolveTypeBinding</code>
	 * forwards to this method. The result is often a function of the context
	 * in which the expression node is embedded as well as the expression 
	 * subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param expression the expression whose type is of interest
	 * @return the binding for the type of the given expression, or 
	 *    <code>null</code> if no binding is available
	 */
	ITypeBinding resolveExpressionType(Expression expression) {
		return null;
	}

	/**
	 * Resolves the given field access and returns the binding for it.
	 * <p>
	 * The implementation of <code>FieldAccess.resolveFieldBinding</code>
	 * forwards to this method. How the field resolves is often a function of
	 * the context in which the field access node is embedded as well as
	 * the field access subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param fieldAccess the field access of interest
	 * @return the binding for the given field access, or 
	 *    <code>null</code> if no binding is available
	 */
	IVariableBinding resolveField(FieldAccess fieldAccess) {
		return null;
	}
		
	/**
	 * Resolves the given super field access and returns the binding for it.
	 * <p>
	 * The implementation of <code>SuperFieldAccess.resolveFieldBinding</code>
	 * forwards to this method. How the field resolves is often a function of
	 * the context in which the super field access node is embedded as well as
	 * the super field access subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param fieldAccess the super field access of interest
	 * @return the binding for the given field access, or 
	 *    <code>null</code> if no binding is available
	 */
	IVariableBinding resolveField(SuperFieldAccess fieldAccess) {
		return null;
	}

	/**
	 * Resolves the given import declaration and returns the binding for it.
	 * <p>
	 * The implementation of <code>ImportDeclaration.resolveBinding</code>
	 * forwards to this method.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param importDeclaration the import declaration of interest
	 * @return the binding for the given package declaration, or 
	 * @return the package binding (for on-demand imports) or type binding
	 *    (for single-type imports), or <code>null</code> if no binding is
	 *    available
	 */
	IBinding resolveImport(ImportDeclaration importDeclaration) {
		return null;
	}
	
	/**
	 * Resolves the given package declaration and returns the binding for it.
	 * <p>
	 * The implementation of <code>PackageDeclaration.resolveBinding</code>
	 * forwards to this method.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param pkg the package declaration of interest
	 * @return the binding for the given package declaration, or 
	 *    <code>null</code> if no binding is available
	 */
	IPackageBinding resolvePackage(PackageDeclaration pkg) {
		return null;
	}
	
	/**
	 * Resolves and returns the binding for the constructor being invoked.
	 * <p>
	 * The implementation of
	 * <code>ConstructorInvocation.resolveConstructor</code>
	 * forwards to this method. Which constructor is invoked is often a function
	 * of the context in which the expression node is embedded as well as
	 * the expression subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param expression the expression of interest
	 * @return the binding for the constructor being invoked, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveConstructor(ConstructorInvocation expression) {
		return null;
	}
	
	/**
	 * Resolves and returns the binding for the constructor being invoked.
	 * <p>
	 * The implementation of
	 * <code>SuperConstructorInvocation.resolveConstructor</code>
	 * forwards to this method. Which constructor is invoked is often a function
	 * of the context in which the expression node is embedded as well as
	 * the expression subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param expression the expression of interest
	 * @return the binding for the constructor being invoked, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveConstructor(SuperConstructorInvocation expression) {
		return null;
	}
	
	/**
	 * Resolves and returns the binding for the constructor being invoked.
	 * <p>
	 * The implementation of
	 * <code>ClassInstanceCreation.resolveConstructor</code>
	 * forwards to this method. Which constructor is invoked is often a function
	 * of the context in which the expression node is embedded as well as
	 * the expression subtree itself.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param expression the expression of interest
	 * @return the binding for the constructor being invoked, or 
	 *    <code>null</code> if no binding is available
	 */
	IMethodBinding resolveConstructor(ClassInstanceCreation expression) {
		return null;
	}
	
	/**
	 * Finds the corresponding AST node from which the given binding originated.
	 * Returns <code>null</code> if the binding does not correspond to any node
	 * in the compilation unit.
	 * <p>
	 * The following table indicates the expected node type for the various
	 * different kinds of bindings:
	 * <ul>
	 * <li></li>
	 * <li>package - a <code>PackageDeclaration</code></li>
	 * <li>class or interface - a <code>TypeDeclaration</code> or a
	 *    <code>ClassInstanceCreation</code> (for anonymous classes) </li>
	 * <li>primitive type - none</li>
	 * <li>array type - none</li>
	 * <li>field - a <code>VariableDeclarationFragment</code> in a 
	 *    <code>FieldDeclaration</code> </li>
	 * <li>local variable - a <code>SingleVariableDeclaration</code>, or
	 *    a <code>VariableDeclarationFragment</code> in a 
	 *    <code>VariableDeclarationStatement</code> or 
	 *    <code>VariableDeclarationExpression</code></li>
	 * <li>method - a <code>MethodDeclaration</code> </li>
	 * <li>constructor - a <code>MethodDeclaration</code> </li>
	 * </ul>
	 * </p>
	 * <p>
	 * The implementation of <code>CompilationUnit.findDeclaringNode</code>
	 * forwards to this method.
	 * </p>
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param binding the binding
	 * @return the corresponding node where the bindings is declared, 
	 *    or <code>null</code> if none
	 */
	ASTNode findDeclaringNode(IBinding binding) {
		return null;
	}

	/**
	 * Finds the corresponding AST node from which the given binding key originated.
	 * 
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param bindingKey the binding key
	 * @return the corresponding node where the bindings is declared, 
	 *    or <code>null</code> if none
	 */
	ASTNode findDeclaringNode(String bindingKey) {
		return null;
	}
	
	/**
	 * Returns the new type binding corresponding to the given old type binding.
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param referenceBinding the old type binding
	 * @return the new type binding
	 */
	ITypeBinding getTypeBinding(org.eclipse.jdt.internal.compiler.lookup.TypeBinding referenceBinding) {
		return null;
	}

	/**
	 * Returns the new package binding corresponding to the given old package binding.
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param packageBinding the old package binding
	 * @return the new package binding
	 */
	IPackageBinding getPackageBinding(org.eclipse.jdt.internal.compiler.lookup.PackageBinding packageBinding) {
		return null;
	}		

	/**
	 * Returns the new method binding corresponding to the given old method binding.
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param methodBinding the old method binding
	 * @return the new method binding
	 */
	IMethodBinding getMethodBinding(org.eclipse.jdt.internal.compiler.lookup.MethodBinding methodBinding) {
		return null;
	}
	
	/**
	 * Returns the new variable binding corresponding to the given old variable binding.
	 * <p>
	 * The default implementation of this method returns <code>null</code>.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param variableBinding the old variable binding
	 * @return the new variable binding
	 */
	IVariableBinding getVariableBinding(org.eclipse.jdt.internal.compiler.lookup.VariableBinding binding) {
		return null;
	}
	
	/**
	 * Allows the user to update information about the given old/new pair of
	 * AST nodes.
	 * <p>
	 * The default implementation of this method does nothing.
	 * Subclasses may reimplement.
	 * </p>
	 * 
	 * @param node the old AST node
	 * @param newNode the new AST node
	 */
	void updateKey(ASTNode node, ASTNode newNode) {
	}
	
	/**
	 * Allows the user to get information about the given old/new pair of
	 * AST nodes.
	 * <p>
	 * The default implementation of this method does nothing.
	 * Subclasses may reimplement.
	 * </p>
	 *
	 * @param currentNode the new node
	 * @return AstNode
	 */
	AstNode getCorrespondingNode(ASTNode currentNode) {
		return null;
	} 

	/**
	 * This method is used to record the scope and its corresponding node.
	 * <p>
	 * The default implementation of this method does nothing.
	 * Subclasses may reimplement.
	 * </p>
	 * @param astNode
	 */	
	void recordScope(ASTNode astNode, BlockScope blockScope) {
	}
}