/*
    * Copyright (c) 2006 JMockit developers
    * This file is subject to the terms of the MIT license (see LICENSE.txt).
    */
   package mockit.internal.util;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
   import edu.umd.cs.findbugs.annotations.Nullable;
   
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  import mockit.internal.state.TestRun;
  
  public final class ClassLoad {
      public static final String OBJECT = "java/lang/Object";
  
      private static final ClassLoader THIS_CL = ClassLoad.class.getClassLoader();
      private static final Map<String, Class<?>> LOADED_CLASSES = new ConcurrentHashMap<>();
      private static final Map<String, String> SUPER_CLASSES = new ConcurrentHashMap<>();
  
      private ClassLoad() {
      }
  
      public static void registerLoadedClass(@NonNull Class<?> aClass) {
          LOADED_CLASSES.put(aClass.getName(), aClass);
      }
  
      @NonNull
      public static <T> Class<T> loadByInternalName(@NonNull String internalClassName) {
          return loadClass(internalClassName.replace('/', '.'));
      }
  
      @NonNull
      public static <T> Class<T> loadClass(@NonNull String className) {
          @Nullable
          Class<?> loadedClass = LOADED_CLASSES.get(className);
  
          if (loadedClass == null) {
              try {
                  loadedClass = loadClassFromAClassLoader(className);
              } catch (LinkageError e) {
                  e.printStackTrace();
                  throw e;
              }
          }
  
          // noinspection unchecked
          return (Class<T>) loadedClass;
      }
  
      @NonNull
      private static Class<?> loadClassFromAClassLoader(@NonNull String className) {
          Class<?> loadedClass = loadClass(null, className);
  
          if (loadedClass == null) {
              if (className.startsWith("mockit.")) {
                  loadedClass = loadClass(THIS_CL, className);
              }
  
              if (loadedClass == null) {
                  Class<?> testClass = TestRun.getCurrentTestClass();
                  loadedClass = testClass == null ? null : loadClass(testClass.getClassLoader(), className);
  
                  if (loadedClass == null) {
                      ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
                      loadedClass = loadClass(contextCL, className);
  
                      if (loadedClass == null) {
                          throw new IllegalArgumentException("No class with name \"" + className + "\" found");
                      }
                  }
              }
          }
  
          return loadedClass;
      }
  
      @NonNull
      public static <T> Class<T> loadClassAtStartup(@NonNull String className) {
          ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
          Class<?> loadedClass;
  
          try {
              loadedClass = loadClass(contextCL, className);
  
              if (loadedClass == null) {
                  loadedClass = loadClass(THIS_CL, className);
  
                  if (loadedClass == null) {
                      throw new IllegalArgumentException("No class with name \"" + className + "\" found");
                  }
              }
          } catch (LinkageError e) {
              e.printStackTrace();
              throw e;
          }
  
          // noinspection unchecked
         return (Class<T>) loadedClass;
     }
 
     @Nullable
     public static Class<?> loadClass(@Nullable ClassLoader loader, @NonNull String className) {
         try {
             return Class.forName(className, false, loader);
         } catch (ClassNotFoundException ignore) {
             return null;
         }
     }
 
     @NonNull
     public static <T> Class<T> loadFromLoader(@Nullable ClassLoader loader, @NonNull String className) {
         try {
             // noinspection unchecked
             return (Class<T>) Class.forName(className, false, loader);
         } catch (ClassNotFoundException ignore) {
             throw new IllegalArgumentException("No class with name \"" + className + "\" found");
         }
     }
 
     @Nullable
     public static <T> Class<? extends T> searchTypeInClasspath(@NonNull String typeName) {
         return searchTypeInClasspath(typeName, false);
     }
 
     @Nullable
     public static <T> Class<? extends T> searchTypeInClasspath(@NonNull String typeName, boolean initializeType) {
         // noinspection OverlyBroadCatchBlock
         try {
             // noinspection unchecked
             return (Class<? extends T>) Class.forName(typeName, initializeType, THIS_CL);
         } catch (Throwable ignore) {
             return null;
         }
     }
 
     public static void addSuperClass(@NonNull String classInternalName, @NonNull String superClassInternalName) {
         SUPER_CLASSES.put(classInternalName.intern(), superClassInternalName.intern());
     }
 
     @NonNull
     public static String getSuperClass(@NonNull String classInternalName) {
         String classDesc = classInternalName.intern();
         String superName = SUPER_CLASSES.get(classDesc);
 
         if (superName == null) {
             Class<?> theClass = loadByInternalName(classDesc);
             Class<?> superClass = theClass.getSuperclass();
 
             if (superClass != null) {
                 superName = superClass.getName().replace('.', '/').intern();
                 SUPER_CLASSES.put(classDesc, superName);
             }
         }
 
         return superName == null ? OBJECT : superName;
     }
 
     @Nullable
     public static String whichIsSuperClass(@NonNull String internalClassName1, @NonNull String internalClassName2) {
         String class1 = actualSuperClass(internalClassName1, internalClassName2);
 
         if (class1 != null) {
             return class1;
         }
 
         return actualSuperClass(internalClassName2, internalClassName1);
     }
 
     @Nullable
     private static String actualSuperClass(@NonNull String candidateSuperClass, @NonNull String candidateSubclass) {
         String subclass = candidateSubclass;
 
         while (true) {
             String superClass = getSuperClass(subclass);
 
             if (superClass.equals(OBJECT)) {
                 return null;
             }
 
             if (superClass.equals(candidateSuperClass)) {
                 return candidateSuperClass;
             }
 
             subclass = superClass;
         }
     }
 
     public static boolean isClassLoaderWithNoDirectAccess(@Nullable ClassLoader classLoader) {
         return classLoader == null || classLoader != THIS_CL && classLoader.getParent() != THIS_CL;
     }
 
     public static ClassLoader getClassLoaderWithAccess(@NonNull Class<?> classToBeAccessed) {
         ClassLoader cl = classToBeAccessed.getClassLoader();
         return isClassLoaderWithNoDirectAccess(cl) ? THIS_CL : cl;
     }
 }