/*

  * Copyright (c) 2011 David Saff

  * Copyright (c) 2011 Christian Gruber

  *

  * 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.truth0;

 import java.util.ArrayList;

 import java.util.List;

 import org.junit.rules.MethodRule;

 import org.junit.runners.model.FrameworkMethod;

 import org.junit.runners.model.Statement;

 import com.google.common.annotations.GwtIncompatible;

 @GwtIncompatible("JUnit4")

 @SuppressWarnings("deprecation")

 public class Expect extends TestVerb implements MethodRule {

   protected static class ExpectationGatherer implements FailureStrategy {

     List<String> messages = new ArrayList<String>();

     @Override public void fail(String message) {

       messages.add(message);

     }

   }

   private final ExpectationGatherer gatherer;

   private boolean inRuleContext = false;

   public static Expect create() {

     return new Expect(new ExpectationGatherer());

   }

   Expect(ExpectationGatherer gatherer) {

     super(gatherer);

     this.gatherer = gatherer;

   }

   @Override

   protected FailureStrategy getFailureStrategy() {

           if (!inRuleContext) {

                   String message = "assertion made on Expect instance, but it's not enabled as a @Rule.";

                         throw new IllegalStateException(message);

           }

           return super.getFailureStrategy();

   }

   // TODO(cgruber): Make this override TestRule when 4.9 is released.

   @Override public Statement apply(final Statement base,

       FrameworkMethod method, Object target) {

     return new Statement() {

       @Override public void evaluate() throws Throwable {

         inRuleContext = true;

         base.evaluate();

         inRuleContext = false;

         if (!gatherer.messages.isEmpty()) {

           StringBuilder message = new StringBuilder("All failed expectations:\n");

           for (int i = 0; i < gatherer.messages.size(); i++) {

             message.append("  ").append(i + 1).append(". ")

                    .append(gatherer.messages.get(i)).append("\n");

           }

           throw new AssertionError(message.toString());

         }

       }

     };

   }

 }