import android.content.Intent;
import android.os.Handler;
import android.os.Message;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.List;

public class HookUtil {

    private static final String TARGET_INTENT = "target_intent";

    // 使用代理的Activity替换需要启动的未注册的Activity
    public static void hookAMS() {
        try {
            Class<?> clazz = Class.forName("android.app.ActivityTaskManager");
            Field singletonField = clazz.getDeclaredField("IActivityTaskManagerSingleton");

            singletonField.setAccessible(true);
            Object singleton = singletonField.get(null);

            Class<?> singletonClass = Class.forName("android.util.Singleton");
            Field mInstanceField = singletonClass.getDeclaredField("mInstance");
            mInstanceField.setAccessible(true);
            Method getMethod = singletonClass.getMethod("get");
            Object mInstance = getMethod.invoke(singleton);

            Class IActivityTaskManagerClass = Class.forName("android.app.IActivityTaskManager");

            Object mInstanceProxy = Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
                    new Class[]{IActivityTaskManagerClass}, new InvocationHandler() {
                        @Override
                        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

                            if ("startActivity".equals(method.getName())) {
                                int index = -1;

                                // 获取 Intent 参数在 args 数组中的index值
                                for (int i = 0; i < args.length; i++) {
                                    if (args[i] instanceof Intent) {
                                        index = i;
                                        break;
                                    }
                                }
                                // 生成代理proxyIntent
                                Intent proxyIntent = new Intent();

                                // 设置启动注册过的ProxyActivity
                                proxyIntent.setClassName("com.package.project", ProxyActivity.class.getName());

                                // 原始Intent作为参数保存到代理Intent中
                                Intent intent = (Intent) args[index];
                                proxyIntent.putExtra(TARGET_INTENT, intent);

                                // 使用proxyIntent替换数组中的Intent
                                args[index] = proxyIntent;
                            }

                            // 原来流程
                            return method.invoke(mInstance, args);
                        }
                    });

            // 用代理的对象替换系统的对象
            mInstanceField.set(singleton, mInstanceProxy);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 需要启动的未注册的Activity 替换回来  ProxyActivity
    public static void hookHandler() {
        try {
            Class<?> clazz = Class.forName("android.app.ActivityThread");

            Field activityThreadField = clazz.getDeclaredField("sCurrentActivityThread");
            activityThreadField.setAccessible(true);
            Object activityThread = activityThreadField.get(null);

            Field mHField = clazz.getDeclaredField("mH");
            mHField.setAccessible(true);
            final Handler mH = (Handler) mHField.get(activityThread);

            Field mCallbackField = Handler.class.getDeclaredField("mCallback");
            mCallbackField.setAccessible(true);

            mCallbackField.set(mH, new Handler.Callback() {

                @Override
                public boolean handleMessage(Message msg) {
                    switch (msg.what) {
                        case 159:
                            // msg.obj = ClientTransaction
                            try {
                                // 获取 List<ClientTransactionItem> mActivityCallbacks 对象
                                Field mActivityCallbacksField = msg.obj.getClass()
                                        .getDeclaredField("mActivityCallbacks");
                                mActivityCallbacksField.setAccessible(true);
                                List mActivityCallbacks = (List) mActivityCallbacksField.get(msg.obj);

                                for (int i = 0; i < mActivityCallbacks.size(); i++) {
                                    // 打印 mActivityCallbacks 的所有item:
                                    //android.app.servertransaction.WindowVisibilityItem
                                    //android.app.servertransaction.LaunchActivityItem

                                    // 如果是 LaunchActivityItem，则获取该类中的 mIntent 值，即 proxyIntent
                                    if (mActivityCallbacks.get(i).getClass().getName()
                                            .equals("android.app.servertransaction.LaunchActivityItem")) {
                                        Object launchActivityItem = mActivityCallbacks.get(i);
                                        Field mIntentField = launchActivityItem.getClass()
                                                .getDeclaredField("mIntent");
                                        mIntentField.setAccessible(true);
                                        Intent proxyIntent = (Intent) mIntentField.get(launchActivityItem);

                                        // 获取启动插件的 Intent，并替换回来
                                        Intent intent = proxyIntent.getParcelableExtra(TARGET_INTENT);
                                        if (intent != null) {
                                            mIntentField.set(launchActivityItem, intent);
                                        }
                                    }
                                }
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                            break;
                    }
                    return false;
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}