/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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.
 */

import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Main {
    public static void main(String[] args) throws Exception {
        try {
            System.loadLibrary(args[0]);
        } catch (UnsatisfiedLinkError ule) {
            usingRI = true;
            // Add expected JNI_OnLoad log line to match expected.txt.
            System.out.println("JNI_OnLoad called");
        }

        testClearDexCache();
        testMultiDex();
        testRacyLoader();
        testRacyLoader2();
        testMisbehavingLoader();
        testRacyMisbehavingLoader();
        testRacyMisbehavingLoader2();
    }

    private static void testClearDexCache() throws Exception {
        DelegatingLoader delegating_loader = createDelegatingLoader();
        Class<?> helper = delegating_loader.loadClass("Helper1");

        WeakReference<Class<?>> weak_test1 = wrapHelperGet(helper);
        changeInner(delegating_loader);
        if (!usingRI) {
            clearResolvedTypes(helper);
        }
        Runtime.getRuntime().gc();
        WeakReference<Class<?>> weak_test2 = wrapHelperGet(helper);

        Class<?> test1 = weak_test1.get();
        if (test1 == null) {
            System.out.println("test1 disappeared");
        }
        Class<?> test2 = weak_test2.get();
        if (test2 == null) {
            System.out.println("test2 disappeared");
        }
        if (test1 != test2) {
            System.out.println("test1 != test2");
        }

        test1 = null;
        test2 = null;
        if (!usingRI) {
            clearResolvedTypes(helper);
        }
        helper = null;
        delegating_loader = null;
        Runtime.getRuntime().gc();
        if (weak_test1.get() != null) {
            System.out.println("weak_test1 still not null");
        }
        if (weak_test2.get() != null) {
            System.out.println("weak_test2 still not null");
        }
        System.out.println("testClearDexCache done");
    }

    private static void testMultiDex() throws Exception {
        DelegatingLoader delegating_loader = createDelegatingLoader();

        Class<?> helper1 = delegating_loader.loadClass("Helper1");
        WeakReference<Class<?>> weak_test1 = wrapHelperGet(helper1);

        changeInner(delegating_loader);

        Class<?> helper2 = delegating_loader.loadClass("Helper2");
        WeakReference<Class<?>> weak_test2 = wrapHelperGet(helper2);

        Class<?> test1 = weak_test1.get();
        if (test1 == null) {
            System.out.println("test1 disappeared");
        }
        Class<?> test2 = weak_test2.get();
        if (test2 == null) {
            System.out.println("test2 disappeared");
        }
        if (test1 != test2) {
            System.out.println("test1 != test2");
        }

        test1 = null;
        test2 = null;
        delegating_loader = null;
        helper1 = null;
        helper2 = null;
        Runtime.getRuntime().gc();
        if (weak_test1.get() != null) {
            System.out.println("weak_test1 still not null");
        }
        if (weak_test2.get() != null) {
            System.out.println("weak_test2 still not null");
        }
        System.out.println("testMultiDex done");
    }

    private static void testMisbehavingLoader() throws Exception {
        ClassLoader system_loader = ClassLoader.getSystemClassLoader();
        DefiningLoader defining_loader = new DefiningLoader(system_loader);
        MisbehavingLoader misbehaving_loader =
            new MisbehavingLoader(system_loader, defining_loader);
        Class<?> helper = misbehaving_loader.loadClass("Helper1");

        try {
            WeakReference<Class<?>> weak_test = wrapHelperGet(helper);
        } catch (InvocationTargetException ite) {
            String message = ite.getCause().getMessage();
            if (usingRI && "Test".equals(message)) {
              // Replace RI message with dalvik message to match expected.txt.
              message = "Initiating class loader of type " +
                  misbehaving_loader.getClass().getName() +
                  " returned class Helper2 instead of Test.";
            }
            System.out.println(ite.getCause().getClass().getName() + ": " + message);
        }
        System.out.println("testMisbehavingLoader done");
    }

    private static void testRacyLoader() throws Exception {
        final ClassLoader system_loader = ClassLoader.getSystemClassLoader();

        final Thread[] threads = new Thread[4];
        final Object[] results = new Object[threads.length];

        final RacyLoader racy_loader = new RacyLoader(system_loader, threads.length);
        final Class<?> helper1 = racy_loader.loadClass("Helper1");

        for (int i = 0; i != threads.length; ++i) {
            final int my_index = i;
            Thread t = new Thread() {
                public void run() {
                    try {
                        Method get = helper1.getDeclaredMethod("get");
                        results[my_index] = get.invoke(null);
                    } catch (InvocationTargetException ite) {
                        results[my_index] = ite.getCause();
                    } catch (Throwable t) {
                        results[my_index] = t;
                    }
                }
            };
            t.start();
            threads[i] = t;
        }
        for (Thread t : threads) {
            t.join();
        }
        dumpResultStats(results);
        System.out.println("testRacyLoader done");
    }

    private static void testRacyLoader2() throws Exception {
        final ClassLoader system_loader = ClassLoader.getSystemClassLoader();

        final Thread[] threads = new Thread[4];
        final Object[] results = new Object[threads.length];

        final RacyLoader racy_loader = new RacyLoader(system_loader, threads.length);
        final Class<?> helper1 = racy_loader.loadClass("Helper1");
        final Class<?> helper3 = racy_loader.loadClass("Helper3");

        for (int i = 0; i != threads.length; ++i) {
            final int my_index = i;
            Thread t = new Thread() {
                public void run() {
                    try {
                        Class<?> helper = (my_index < threads.length / 2) ? helper1 : helper3;
                        Method get = helper.getDeclaredMethod("get");
                        results[my_index] = get.invoke(null);
                    } catch (InvocationTargetException ite) {
                        results[my_index] = ite.getCause();
                    } catch (Throwable t) {
                        results[my_index] = t;
                    }
                }
            };
            t.start();
            threads[i] = t;
        }
        for (Thread t : threads) {
            t.join();
        }
        dumpResultStats(results);
        System.out.println("testRacyLoader2 done");
    }

    private static void dumpResultStats(Object[] results) throws Exception {
        int throwables = 0;
        int class_weaks = 0;
        int unique_class_weaks = 0;
        for (int i = 0; i != results.length; ++i) {
            Object r = results[i];
            if (r instanceof Throwable) {
                ++throwables;
                System.out.println(((Throwable) r).getMessage());
            } else if (isClassPair(r)) {
                printPair(r);
                Object ref = getSecond(r);
                ++class_weaks;
                ++unique_class_weaks;
                for (int j = 0; j != i; ++j) {
                    Object rj = results[j];
                    if (isClassPair(results[j]) && getSecond(results[j]) == ref) {
                        --unique_class_weaks;
                        break;
                    }
                }
            }
        }
        System.out.println("total: " + results.length);
        System.out.println("  throwables: " + throwables);
        System.out.println("  class_weaks: " + class_weaks
            + " (" + unique_class_weaks + " unique)");
    }

    private static void testRacyMisbehavingLoader() throws Exception {
        final ClassLoader system_loader = ClassLoader.getSystemClassLoader();

        final Thread[] threads = new Thread[4];
        final Object[] results = new Object[threads.length];

        final RacyMisbehavingLoader racy_loader =
            new RacyMisbehavingLoader(system_loader, threads.length, false);
        final Class<?> helper1 = racy_loader.loadClass("RacyMisbehavingHelper");

        for (int i = 0; i != threads.length; ++i) {
            final int my_index = i;
            Thread t = new Thread() {
                public void run() {
                    try {
                        Method get = helper1.getDeclaredMethod("get");
                        results[my_index] = get.invoke(null);
                    } catch (InvocationTargetException ite) {
                        results[my_index] = ite.getCause();
                    } catch (Throwable t) {
                        results[my_index] = t;
                    }
                }
            };
            t.start();
            threads[i] = t;
        }
        for (Thread t : threads) {
            t.join();
        }
        dumpResultStats(results);
        System.out.println("testRacyMisbehavingLoader done");
    }

    private static void testRacyMisbehavingLoader2() throws Exception {
      final ClassLoader system_loader = ClassLoader.getSystemClassLoader();

      final Thread[] threads = new Thread[4];
      final Object[] results = new Object[threads.length];

      final RacyMisbehavingLoader racy_loader =
          new RacyMisbehavingLoader(system_loader, threads.length, true);
      final Class<?> helper1 = racy_loader.loadClass("RacyMisbehavingHelper");

      for (int i = 0; i != threads.length; ++i) {
          final int my_index = i;
          Thread t = new Thread() {
              public void run() {
                  try {
                      Method get = helper1.getDeclaredMethod("get");
                      results[my_index] = get.invoke(null);
                  } catch (InvocationTargetException ite) {
                      results[my_index] = ite.getCause();
                  } catch (Throwable t) {
                      results[my_index] = t;
                  }
              }
          };
          t.start();
          threads[i] = t;
      }
      for (Thread t : threads) {
          t.join();
      }
      dumpResultStats(results);
      System.out.println("testRacyMisbehavingLoader2 done");
  }

    private static DelegatingLoader createDelegatingLoader() {
        ClassLoader system_loader = ClassLoader.getSystemClassLoader();
        DefiningLoader defining_loader = new DefiningLoader(system_loader);
        return new DelegatingLoader(system_loader, defining_loader);
    }

    private static void changeInner(DelegatingLoader delegating_loader) {
        ClassLoader system_loader = ClassLoader.getSystemClassLoader();
        DefiningLoader defining_loader = new DefiningLoader(system_loader);
        delegating_loader.resetDefiningLoader(defining_loader);
    }

    private static WeakReference<Class<?>> wrapHelperGet(Class<?> helper) throws Exception {
        Method get = helper.getDeclaredMethod("get");
        Object pair = get.invoke(null);
        printPair(pair);
        return new WeakReference<Class<?>>(getSecond(pair));
    }

    private static void printPair(Object pair) throws Exception {
        Method print = pair.getClass().getDeclaredMethod("print");
        print.invoke(pair);
    }

    private static Class<?> getSecond(Object pair) throws Exception {
        Field second = pair.getClass().getDeclaredField("second");
        return (Class<?>) second.get(pair);
    }

    private static boolean isClassPair(Object r) {
        return r != null && r.getClass().getName().equals("ClassPair");
    }

    public static native void clearResolvedTypes(Class<?> c);

    static boolean usingRI = false;
}