/*
 * Copyright 2003-2009 Dave Griffith, Bas Leijdekkers
 *
 * 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 com.siyeh.ig.controlflow;

import com.intellij.codeInspection.ProblemDescriptor;
import com.intellij.codeInspection.ui.SingleCheckboxOptionsPanel;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.util.IncorrectOperationException;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.InspectionGadgetsFix;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

import javax.swing.*;

public class ForLoopReplaceableByWhileInspection extends BaseInspection {

  /**
   * @noinspection PublicField
   */
  public boolean m_ignoreLoopsWithoutConditions = false;

  @Override
  @NotNull
  public String getDisplayName() {
    return InspectionGadgetsBundle.message(
      "for.loop.replaceable.by.while.display.name");
  }

  @Override
  @NotNull
  public String getID() {
    return "ForLoopReplaceableByWhile";
  }

  @Override
  @NotNull
  protected String buildErrorString(Object... infos) {
    return InspectionGadgetsBundle.message(
      "for.loop.replaceable.by.while.problem.descriptor");
  }

  @Override
  public JComponent createOptionsPanel() {
    return new SingleCheckboxOptionsPanel(InspectionGadgetsBundle.message(
      "for.loop.replaceable.by.while.ignore.option"),
                                          this, "m_ignoreLoopsWithoutConditions");
  }

  @Override
  public InspectionGadgetsFix buildFix(Object... infos) {
    return new ReplaceForByWhileFix();
  }

  private static class ReplaceForByWhileFix extends InspectionGadgetsFix {

    @NotNull
    public String getName() {
      return InspectionGadgetsBundle.message(
        "for.loop.replaceable.by.while.replace.quickfix");
    }

    @Override
    public void doFix(Project project, ProblemDescriptor descriptor)
      throws IncorrectOperationException {
      final PsiElement forKeywordElement = descriptor.getPsiElement();
      final PsiForStatement forStatement =
        (PsiForStatement)forKeywordElement.getParent();
      assert forStatement != null;
      final PsiExpression condition = forStatement.getCondition();
      final PsiStatement body = forStatement.getBody();
      final String bodyText;
      if (body == null) {
        bodyText = "";
      }
      else {
        bodyText = body.getText();
      }
      @NonNls final String whileStatement;
      if (condition == null) {
        whileStatement = "while(true)" + bodyText;
      }
      else {
        whileStatement = "while(" + condition.getText() + ')' +
                         bodyText;
      }
      replaceStatement(forStatement, whileStatement);
    }
  }

  @Override
  public BaseInspectionVisitor buildVisitor() {
    return new ForLoopReplaceableByWhileVisitor();
  }

  private class ForLoopReplaceableByWhileVisitor
    extends BaseInspectionVisitor {

    @Override
    public void visitForStatement(
      @NotNull PsiForStatement statement) {
      super.visitForStatement(statement);
      final PsiStatement initialization = statement.getInitialization();
      if (initialization != null &&
          !(initialization instanceof PsiEmptyStatement)) {
        return;
      }
      final PsiStatement update = statement.getUpdate();
      if (update != null && !(update instanceof PsiEmptyStatement)) {
        return;
      }
      if (m_ignoreLoopsWithoutConditions) {
        final PsiExpression condition = statement.getCondition();
        if (condition == null) {
          return;
        }
        final String conditionText = condition.getText();
        if (PsiKeyword.TRUE.equals(conditionText)) {
          return;
        }
      }
      registerStatementError(statement);
    }
  }
}