/***********************************************************************************************************************************
 * 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 net.sourceforge.phpeclipse.internal.compiler.ast;

import net.sourceforge.phpdt.internal.compiler.IAbstractSyntaxTreeVisitor;
import net.sourceforge.phpdt.internal.compiler.flow.FlowContext;
import net.sourceforge.phpdt.internal.compiler.flow.FlowInfo;
import net.sourceforge.phpdt.internal.compiler.lookup.BlockScope;
import net.sourceforge.phpdt.internal.compiler.lookup.MethodScope;
import net.sourceforge.phpdt.internal.compiler.lookup.TypeBinding;

public class ThisReference extends Reference {

  public static ThisReference implicitThis() {

    ThisReference implicitThis = new ThisReference(0, 0);
    implicitThis.bits |= IsImplicitThisMask;
    return implicitThis;
  }

  public ThisReference(int sourceStart, int sourceEnd) {

    this.sourceStart = sourceStart;
    this.sourceEnd = sourceEnd;
  }

  /*
   * @see Reference#analyseAssignment(...)
   */
  public FlowInfo analyseAssignment(BlockScope currentScope, FlowContext flowContext, FlowInfo flowInfo, Assignment assignment,
      boolean isCompound) {

    return flowInfo; // this cannot be assigned
  }

  public boolean checkAccess(MethodScope methodScope) {

    // this/super cannot be used in constructor call
    if (methodScope.isConstructorCall) {
      methodScope.problemReporter().fieldsOrThisBeforeConstructorInvocation(this);
      return false;
    }

    // static may not refer to this/super
    if (methodScope.isStatic) {
      methodScope.problemReporter().errorThisSuperInStatic(this);
      return false;
    }
    return true;
  }

  /*
   * @see Reference#generateAssignment(...)
   */
  //	public void generateAssignment(BlockScope currentScope, CodeStream codeStream, Assignment assignment, boolean valueRequired) {
  //
  //		 // this cannot be assigned
  //	}
  //
  //	public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
  //	
  //		int pc = codeStream.position;
  //		if (valueRequired)
  //			codeStream.aload_0();
  //		if ((this.bits & IsImplicitThisMask) == 0) codeStream.recordPositionsFrom(pc, this.sourceStart);
  //	}
  //
  //	/*
  //	 * @see Reference#generateCompoundAssignment(...)
  //	 */
  //	public void generateCompoundAssignment(BlockScope currentScope, CodeStream codeStream, Expression expression, int operator, int
  // assignmentImplicitConversion, boolean valueRequired) {
  //
  //		 // this cannot be assigned
  //	}
  //	
  //	/*
  //	 * @see net.sourceforge.phpdt.internal.compiler.ast.Reference#generatePostIncrement()
  //	 */
  //	public void generatePostIncrement(BlockScope currentScope, CodeStream codeStream, CompoundAssignment postIncrement, boolean
  // valueRequired) {
  //
  //		 // this cannot be assigned
  //	}
  public boolean isImplicitThis() {

    return (this.bits & IsImplicitThisMask) != 0;
  }

  public boolean isThis() {

    return true;
  }

  public TypeBinding resolveType(BlockScope scope) {

    constant = NotAConstant;
    if (!this.isImplicitThis() && !checkAccess(scope.methodScope()))
      return null;
    return this.resolvedType = scope.enclosingSourceType();
  }

  public StringBuffer printExpression(int indent, StringBuffer output) {

    if (this.isImplicitThis())
      return output;
    return output.append("this"); //$NON-NLS-1$
  }

  public String toStringExpression() {

    if (this.isImplicitThis())
      return ""; //$NON-NLS-1$
    return "this"; //$NON-NLS-1$
  }

  public void traverse(IAbstractSyntaxTreeVisitor visitor, BlockScope blockScope) {

    visitor.visit(this, blockScope);
    visitor.endVisit(this, blockScope);
  }
}