/*
* Copyright 2000-2017 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.plugins.groovy.intentions.control;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.PsiElement;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.util.ArrayUtilRt;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.plugins.groovy.codeInspection.utils.ControlFlowUtils;
import org.jetbrains.plugins.groovy.intentions.base.Intention;
import org.jetbrains.plugins.groovy.intentions.base.PsiElementPredicate;
import org.jetbrains.plugins.groovy.lang.psi.GrControlFlowOwner;
import org.jetbrains.plugins.groovy.lang.psi.GroovyPsiElementFactory;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.GrBlockStatement;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.GrIfStatement;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.GrStatement;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.blocks.GrCodeBlock;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.blocks.GrOpenBlock;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrParenthesizedExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrReferenceExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.GrUnaryExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.expressions.path.GrCallExpression;
import org.jetbrains.plugins.groovy.lang.psi.api.util.GrStatementOwner;
import org.jetbrains.plugins.groovy.lang.psi.controlFlow.Instruction;
import org.jetbrains.plugins.groovy.lang.psi.controlFlow.impl.IfEndInstruction;
/**
* @author Niels Harremoes
*/
public class InvertIfIntention extends Intention {
@Override
protected void processIntention(@NotNull PsiElement element, @NotNull Project project, Editor editor) throws IncorrectOperationException {
PsiElement parent = element.getParent();
if (!"if".equals(element.getText()) || !(parent instanceof GrIfStatement)) {
throw new IncorrectOperationException("Not invoked on an if");
}
GrIfStatement parentIf = (GrIfStatement)parent;
GroovyPsiElementFactory groovyPsiElementFactory = GroovyPsiElementFactory.getInstance(project);
GrExpression condition = parentIf.getCondition();
if (condition == null) {
throw new IncorrectOperationException("Invoked on an if with empty condition");
}
GrExpression negatedCondition = null;
if (condition instanceof GrUnaryExpression) {
GrUnaryExpression unaryCondition = (GrUnaryExpression)condition;
if ("!".equals(unaryCondition.getOperationToken().getText())) {
negatedCondition = stripParenthesis(unaryCondition.getOperand());
}
}
if (negatedCondition == null) {
// Now check whether this is a simple expression
condition = stripParenthesis(condition);
String negatedExpressionText;
if (condition instanceof GrCallExpression || condition instanceof GrReferenceExpression) {
negatedExpressionText = "!" + condition.getText();
}
else {
negatedExpressionText = "!(" + condition.getText() + ")";
}
negatedCondition = groovyPsiElementFactory.createExpressionFromText(negatedExpressionText, parentIf);
}
GrStatement thenBranch = parentIf.getThenBranch();
final boolean thenIsNotEmpty = isNotEmpty(thenBranch);
String newIfText = "if (" + negatedCondition.getText() + ") {}";
if (thenIsNotEmpty) {
newIfText += " else {}";
}
GrIfStatement newIf = (GrIfStatement)groovyPsiElementFactory.createStatementFromText(newIfText, parentIf.getContext());
generateElseBranchTextAndRemoveTailStatements(parentIf, newIf);
if (thenIsNotEmpty) {
final GrStatement elseBranch = newIf.getElseBranch();
assert elseBranch != null;
elseBranch.replaceWithStatement(thenBranch);
}
parentIf.replace(newIf);
}
private static boolean isNotEmpty(@Nullable GrStatement thenBranch) {
return thenBranch != null &&
!(thenBranch instanceof GrBlockStatement && ((GrBlockStatement)thenBranch).getBlock().getStatements().length == 0);
}
private static void generateElseBranchTextAndRemoveTailStatements(@NotNull GrIfStatement ifStatement, @NotNull GrIfStatement newIf) {
final GrStatement thenBranch = newIf.getThenBranch();
assert thenBranch != null;
GrStatement elseBranch = ifStatement.getElseBranch();
if (elseBranch != null) {
thenBranch.replaceWithStatement(elseBranch);
return;
}
PsiElement parent = ifStatement.getParent();
if (!(parent instanceof GrStatementOwner)) return;
if (!isTailAfterIf(ifStatement, ((GrStatementOwner)parent))) return;
final PsiElement start = ifStatement.getNextSibling();
PsiElement end = parent instanceof GrCodeBlock ? ((GrCodeBlock)parent).getRBrace().getPrevSibling() : parent.getLastChild();
final GrOpenBlock block = ((GrBlockStatement)thenBranch).getBlock();
block.addRangeAfter(start, end, block.getLBrace());
parent.deleteChildRange(start, end);
}
private static boolean isTailAfterIf(@NotNull GrIfStatement ifStatement, @NotNull GrStatementOwner owner) {
final GrControlFlowOwner flowOwner = ControlFlowUtils.findControlFlowOwner(ifStatement);
if (flowOwner == null) return false;
final Instruction[] flow = flowOwner.getControlFlow();
final GrStatement[] statements = owner.getStatements();
final int index = ArrayUtilRt.find(statements, ifStatement);
if (index == statements.length - 1) return false;
final GrStatement then = ifStatement.getThenBranch();
for (Instruction i : flow) {
final PsiElement element = i.getElement();
if (element == null || !PsiTreeUtil.isAncestor(then, element, true)) continue;
for (Instruction succ : i.allSuccessors()) {
if (succ instanceof IfEndInstruction) {
return false;
}
}
}
return true;
}
@NotNull
private static GrExpression stripParenthesis(GrExpression operand) {
while (operand instanceof GrParenthesizedExpression) {
GrExpression innerExpression = ((GrParenthesizedExpression)operand).getOperand();
if (innerExpression == null) {
break;
}
operand = innerExpression;
}
return operand;
}
@NotNull
@Override
protected PsiElementPredicate getElementPredicate() {
return new PsiElementPredicate() {
@Override
public boolean satisfiedBy(@NotNull PsiElement element) {
PsiElement parent = element.getParent();
if (!(parent instanceof GrIfStatement)) return false;
if (((GrIfStatement)parent).getCondition() == null) return false;
if (!"if".equals(element.getText())) return false;
return true;
}
};
}
}