/*******************************************************************************
 * Copyright (c) 2004, 2015 IBM Corporation and others.
 *
 * This program and the accompanying masterials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     John Camelon (IBM) - Initial API and implementation
 *     Sergey Prigogin (Google)
 *     Mike Kucera (IBM)
 *     Markus Schorn (Wind River Systems)
 *     Sergey Prigogin (Google)
 *******************************************************************************/
package org.eclipse.cdt.internal.core.dom.parser.cpp;

import static org.eclipse.cdt.core.dom.ast.IASTExpression.ValueCategory.LVALUE;

import org.eclipse.cdt.core.dom.ast.ASTVisitor;
import org.eclipse.cdt.core.dom.ast.IASTExpression;
import org.eclipse.cdt.core.dom.ast.IASTIdExpression;
import org.eclipse.cdt.core.dom.ast.IASTImplicitDestructorName;
import org.eclipse.cdt.core.dom.ast.IASTImplicitName;
import org.eclipse.cdt.core.dom.ast.IASTName;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IBinding;
import org.eclipse.cdt.core.dom.ast.IProblemBinding;
import org.eclipse.cdt.core.dom.ast.IType;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTExpression;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTQualifiedName;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTUnaryExpression;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunction;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
import org.eclipse.cdt.internal.core.dom.parser.ASTAmbiguousNode;
import org.eclipse.cdt.internal.core.dom.parser.ASTNode;
import org.eclipse.cdt.internal.core.dom.parser.IASTAmbiguityParent;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPEvaluation;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPSemantics;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.DestructorCallCollector;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalFixed;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalUnary;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.FunctionSetType;

/**
 * Unary expression in c++
 */
public class CPPASTUnaryExpression extends ASTNode implements ICPPASTUnaryExpression, IASTAmbiguityParent {
	private int fOperator;
	private ICPPASTExpression fOperand;
	private ICPPEvaluation fEvaluation;
	private IASTImplicitName[] fImplicitNames;
	private IASTImplicitDestructorName[] fImplicitDestructorNames;

	public CPPASTUnaryExpression() {
	}

	public CPPASTUnaryExpression(int operator, IASTExpression operand) {
		fOperator = operator;
		setOperand(operand);
	}

	@Override
	public CPPASTUnaryExpression copy() {
		return copy(CopyStyle.withoutLocations);
	}

	@Override
	public CPPASTUnaryExpression copy(CopyStyle style) {
		CPPASTUnaryExpression copy = new CPPASTUnaryExpression(fOperator,
				fOperand == null ? null : fOperand.copy(style));
		return copy(copy, style);
	}

	@Override
	public int getOperator() {
		return fOperator;
	}

	@Override
	public void setOperator(int operator) {
		assertNotFrozen();
		fOperator = operator;
	}

	@Override
	public IASTExpression getOperand() {
		return fOperand;
	}

	@Override
	public void setOperand(IASTExpression expression) {
		assertNotFrozen();
		fOperand = (ICPPASTExpression) expression;
		if (expression != null) {
			expression.setParent(this);
			expression.setPropertyInParent(OPERAND);
		}
	}

	public boolean isPostfixOperator() {
		return fOperator == op_postFixDecr || fOperator == op_postFixIncr;
	}

	@Override
	public IASTImplicitName[] getImplicitNames() {
		if (fImplicitNames == null) {
			ICPPFunction overload = getOverload();
			if (overload == null || overload instanceof CPPImplicitFunction) {
				fImplicitNames = IASTImplicitName.EMPTY_NAME_ARRAY;
			} else {
				CPPASTImplicitName operatorName = new CPPASTImplicitName(overload.getNameCharArray(), this);
				operatorName.setOperator(true);
				operatorName.setBinding(overload);
				operatorName.computeOperatorOffsets(fOperand, isPostfixOperator());
				fImplicitNames = new IASTImplicitName[] { operatorName };
			}
		}

		return fImplicitNames;
	}

	@Override
	public IASTImplicitDestructorName[] getImplicitDestructorNames() {
		if (fImplicitDestructorNames == null) {
			fImplicitDestructorNames = DestructorCallCollector.getTemporariesDestructorCalls(this);
		}

		return fImplicitDestructorNames;
	}

	@Override
	public boolean accept(ASTVisitor action) {
		if (action.shouldVisitExpressions) {
			switch (action.visit(this)) {
			case ASTVisitor.PROCESS_ABORT:
				return false;
			case ASTVisitor.PROCESS_SKIP:
				return true;
			default:
				break;
			}
		}

		final boolean isPostfix = isPostfixOperator();

		if (!isPostfix && action.shouldVisitImplicitNames) {
			for (IASTImplicitName name : getImplicitNames()) {
				if (!name.accept(action))
					return false;
			}
		}

		if (fOperand != null && !fOperand.accept(action))
			return false;

		if (isPostfix && action.shouldVisitImplicitNames) {
			for (IASTImplicitName name : getImplicitNames()) {
				if (!name.accept(action))
					return false;
			}
		}

		if (action.shouldVisitImplicitDestructorNames && !acceptByNodes(getImplicitDestructorNames(), action))
			return false;

		if (action.shouldVisitExpressions) {
			switch (action.leave(this)) {
			case ASTVisitor.PROCESS_ABORT:
				return false;
			case ASTVisitor.PROCESS_SKIP:
				return true;
			default:
				break;
			}
		}
		return true;
	}

	@Override
	public void replace(IASTNode child, IASTNode other) {
		if (child == fOperand) {
			other.setPropertyInParent(child.getPropertyInParent());
			other.setParent(child.getParent());
			fOperand = (ICPPASTExpression) other;
		}
	}

	@Override
	public ICPPFunction getOverload() {
		ICPPEvaluation eval = getEvaluation();
		if (eval instanceof EvalUnary) {
			CPPSemantics.pushLookupPoint(this);
			try {
				return ((EvalUnary) eval).getOverload();
			} finally {
				CPPSemantics.popLookupPoint();
			}
		}
		return null;
	}

	@Override
	public ICPPEvaluation getEvaluation() {
		if (fEvaluation == null) {
			fEvaluation = computeEvaluation();
		}
		return fEvaluation;
	}

	private ICPPEvaluation computeEvaluation() {
		if (fOperand == null || fOperand instanceof ASTAmbiguousNode)
			return EvalFixed.INCOMPLETE;

		final ICPPEvaluation nestedEval = fOperand.getEvaluation();

		if (nestedEval.isFunctionSet() && fOperator == op_amper) {
			return nestedEval;
		}

		IBinding addressOfQualifiedNameBinding = null;
		if (fOperator == op_amper && fOperand instanceof IASTIdExpression) {
			IASTName name = ((IASTIdExpression) fOperand).getName();
			if (name instanceof ICPPASTQualifiedName) {
				addressOfQualifiedNameBinding = name.resolveBinding();
				if (addressOfQualifiedNameBinding instanceof IProblemBinding)
					return EvalFixed.INCOMPLETE;
			}
		}
		return new EvalUnary(fOperator, nestedEval, addressOfQualifiedNameBinding, this);
	}

	@Override
	public IType getExpressionType() {
		IType type = CPPEvaluation.getType(this);
		if (type instanceof FunctionSetType) {
			type = fOperand.getExpressionType();
			if (fOperator == op_amper) {
				if (fOperand instanceof IASTIdExpression) {
					IASTIdExpression idExpr = (IASTIdExpression) fOperand;
					final IASTName name = idExpr.getName();
					if (name instanceof ICPPASTQualifiedName) {
						IBinding binding = name.resolveBinding();
						if (binding instanceof ICPPMethod) {
							ICPPMethod method = (ICPPMethod) binding;
							if (!method.isStatic()) {
								return new CPPPointerToMemberType(method.getType(), method.getClassOwner(), false,
										false, false);
							}
						}
					}
				}
				return new CPPPointerType(type);
			}
		}
		return type;
	}

	@Override
	public ValueCategory getValueCategory() {
		return CPPEvaluation.getValueCategory(this);
	}

	@Override
	public boolean isLValue() {
		return getValueCategory() == LVALUE;
	}
}
