/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.startup;
   
   import static java.util.Arrays.asList;
   
   import static mockit.internal.util.ClassLoad.loadClassAtStartup;
  import static mockit.internal.util.ClassLoad.searchTypeInClasspath;
  
  import edu.umd.cs.findbugs.annotations.NonNull;
  
  import java.lang.instrument.Instrumentation;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Set;
  
  import mockit.MockUp;
  import mockit.coverage.CodeCoverage;
  import mockit.integration.junit4.FakeFrameworkMethod;
  import mockit.integration.junit4.FakeRunNotifier;
  import mockit.internal.reflection.ConstructorReflection;
  import mockit.internal.util.StackTrace;
  
  final class JMockitInitialization {
      private JMockitInitialization() {
      }
  
      static void initialize(@NonNull Instrumentation inst, boolean activateCoverage) {
          if (activateCoverage || CodeCoverage.active()) {
              inst.addTransformer(new CodeCoverage());
          }
  
          applyInternalStartupFakesAsNeeded();
          applyUserSpecifiedStartupFakesIfAny();
      }
  
      private static void applyInternalStartupFakesAsNeeded() {
          if (searchTypeInClasspath("org.junit.runners.model.FrameworkMethod", true) != null
                  || searchTypeInClasspath("org.junit.vintage.engine.VintageTestEngine", true) != null) {
              new FakeRunNotifier();
              new FakeFrameworkMethod();
          }
  
          if (searchTypeInClasspath("org.junit.jupiter.api.extension.Extension", true) != null) {
              System.setProperty("junit.jupiter.extensions.autodetection.enabled", "true");
          }
      }
  
      private static void applyUserSpecifiedStartupFakesIfAny() {
          Collection<String> fakeClasses = getFakeClasses();
  
          for (String fakeClassName : fakeClasses) {
              applyStartupFake(fakeClassName);
          }
      }
  
      @NonNull
      private static Collection<String> getFakeClasses() {
          String commaOrSpaceSeparatedValues = System.getProperty("fakes");
  
          if (commaOrSpaceSeparatedValues == null) {
              return Collections.emptyList();
          }
  
          // noinspection DynamicRegexReplaceableByCompiledPattern
          String[] fakeClassNames = commaOrSpaceSeparatedValues.split("\\s*,\\s*|\\s+");
          Set<String> uniqueClassNames = new HashSet<>(asList(fakeClassNames));
          uniqueClassNames.remove("");
          return uniqueClassNames;
      }
  
      private static void applyStartupFake(@NonNull String fakeClassName) {
          String argument = null;
          int p = fakeClassName.indexOf('=');
  
          if (p > 0) {
              argument = fakeClassName.substring(p + 1);
              fakeClassName = fakeClassName.substring(0, p);
          }
  
          try {
              Class<?> fakeClass = loadClassAtStartup(fakeClassName);
  
              if (MockUp.class.isAssignableFrom(fakeClass)) {
                  if (argument == null) {
                      ConstructorReflection.newInstanceUsingDefaultConstructor(fakeClass);
                  } else {
                      ConstructorReflection.newInstanceUsingCompatibleConstructor(fakeClass, argument);
                  }
              }
          } catch (UnsupportedOperationException ignored) {
          } catch (Throwable unexpectedFailure) {
              StackTrace.filterStackTrace(unexpectedFailure);
              unexpectedFailure.printStackTrace();
          }
      }
 }