/*
    * MIT License
    * Copyright (c) 2006-2025 JMockit developers
    * See LICENSE file for full license text.
    */
   package mockit.coverage.testRedundancy;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
   import edu.umd.cs.findbugs.annotations.Nullable;
  
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import mockit.coverage.Configuration;
  
  import org.checkerframework.checker.index.qual.NonNegative;
  
  public final class TestCoverage {
      @Nullable
      public static final TestCoverage INSTANCE;
  
      static {
          INSTANCE = "true".equals(Configuration.getProperty("redundancy")) ? new TestCoverage() : null;
      }
  
      @NonNull
      private final Map<Method, Integer> testsToItemsCovered = new LinkedHashMap<>();
      @Nullable
      private Method currentTestMethod;
  
      private TestCoverage() {
      }
  
      public void setCurrentTestMethod(@Nullable Method testMethod) {
          if (testMethod != null) {
              testsToItemsCovered.put(testMethod, 0);
          }
  
          currentTestMethod = testMethod;
      }
  
      public void recordNewItemCoveredByTestIfApplicable(@NonNegative int previousExecutionCount) {
          if (previousExecutionCount == 0 && currentTestMethod != null) {
              Integer itemsCoveredByTest = testsToItemsCovered.get(currentTestMethod);
              testsToItemsCovered.put(currentTestMethod, itemsCoveredByTest == null ? 1 : itemsCoveredByTest + 1);
          }
      }
  
      @NonNull
      public List<Method> getRedundantTests() {
          List<Method> redundantTests = new ArrayList<>();
  
          for (Entry<Method, Integer> testAndItemsCovered : testsToItemsCovered.entrySet()) {
              Method testMethod = testAndItemsCovered.getKey();
              Integer itemsCovered = testAndItemsCovered.getValue();
  
              if (itemsCovered == 0) {
                  redundantTests.add(testMethod);
              }
          }
  
          return redundantTests;
      }
  }