/*
 * Copyright (C) 2013 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.
 */

package org.mozilla.gecko.background.preferences;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.preference.Preference;
import android.preference.PreferenceManager;
import android.preference.PreferenceScreen;
import android.util.Log;

public class PreferenceManagerCompat {

  private static final String TAG = PreferenceManagerCompat.class.getSimpleName();

  /**
   * Interface definition for a callback to be invoked when a {@link Preference} in the hierarchy
   * rooted at this {@link PreferenceScreen} is clicked.
   */
  interface OnPreferenceTreeClickListener {
    /**
     * Called when a preference in the tree rooted at this {@link PreferenceScreen} has been
     * clicked.
     *
     * @param preferenceScreen The {@link PreferenceScreen} that the preference is located in.
     * @param preference       The preference that was clicked.
     *
     * @return Whether the click was handled.
     */
    boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference);
  }

  static PreferenceManager newInstance(Activity activity, int firstRequestCode) {
    try {
      Constructor<PreferenceManager> c = PreferenceManager.class.getDeclaredConstructor(Activity.class, int.class);
      c.setAccessible(true);
      return c.newInstance(activity, firstRequestCode);
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call constructor PreferenceManager by reflection", e);
    }
    return null;
  }

  /**
   * Sets the owning preference fragment
   */
  static void setFragment(PreferenceManager manager, PreferenceFragment fragment) {
    // stub
  }

  /**
   * Sets the callback to be invoked when a {@link Preference} in the hierarchy rooted at this
   * {@link PreferenceManager} is clicked.
   *
   * @param listener The callback to be invoked.
   */
  static void setOnPreferenceTreeClickListener(PreferenceManager manager, final OnPreferenceTreeClickListener listener) {
    try {
      Field onPreferenceTreeClickListener = PreferenceManager.class.getDeclaredField("mOnPreferenceTreeClickListener");
      onPreferenceTreeClickListener.setAccessible(true);
      if (listener != null) {
        Object proxy = Proxy.newProxyInstance(
          onPreferenceTreeClickListener.getType().getClassLoader(),
          new Class<?>[] { onPreferenceTreeClickListener.getType() },
          new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) {
              if (method.getName().equals("onPreferenceTreeClick")) {
                return listener.onPreferenceTreeClick((PreferenceScreen) args[0], (Preference) args[1]);
              } else {
                return null;
              }
            }
          });
        onPreferenceTreeClickListener.set(manager, proxy);
      } else {
        onPreferenceTreeClickListener.set(manager, null);
      }
    } catch (Exception e) {
      Log.w(TAG, "Couldn't set PreferenceManager.mOnPreferenceTreeClickListener by reflection", e);
    }
  }

  /**
   * Inflates a preference hierarchy from the preference hierarchies of {@link Activity Activities}
   * that match the given {@link Intent}. An {@link Activity} defines its preference hierarchy with
   * meta-data using the {@link #METADATA_KEY_PREFERENCES} key.
   * <p/>
   * If a preference hierarchy is given, the new preference hierarchies will be merged in.
   *
   * @param queryIntent     The intent to match activities.
   * @param rootPreferences Optional existing hierarchy to merge the new hierarchies into.
   *
   * @return The root hierarchy (if one was not provided, the new hierarchy's root).
   */
  static PreferenceScreen inflateFromIntent(PreferenceManager manager, Intent intent, PreferenceScreen screen) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("inflateFromIntent", Intent.class, PreferenceScreen.class);
      m.setAccessible(true);
      PreferenceScreen prefScreen = (PreferenceScreen) m.invoke(manager, intent, screen);
      return prefScreen;
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.inflateFromIntent by reflection", e);
    }
    return null;
  }

  /**
   * Inflates a preference hierarchy from XML. If a preference hierarchy is given, the new
   * preference hierarchies will be merged in.
   *
   * @param context         The context of the resource.
   * @param resId           The resource ID of the XML to inflate.
   * @param rootPreferences Optional existing hierarchy to merge the new hierarchies into.
   *
   * @return The root hierarchy (if one was not provided, the new hierarchy's root).
   *
   * @hide
   */
  static PreferenceScreen inflateFromResource(PreferenceManager manager, Activity activity, int resId, PreferenceScreen screen) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("inflateFromResource", Context.class, int.class, PreferenceScreen.class);
      m.setAccessible(true);
      PreferenceScreen prefScreen = (PreferenceScreen) m.invoke(manager, activity, resId, screen);
      return prefScreen;
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.inflateFromResource by reflection", e);
    }
    return null;
  }

  /**
   * Returns the root of the preference hierarchy managed by this class.
   *
   * @return The {@link PreferenceScreen} object that is at the root of the hierarchy.
   */
  static PreferenceScreen getPreferenceScreen(PreferenceManager manager) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("getPreferenceScreen");
      m.setAccessible(true);
      return (PreferenceScreen) m.invoke(manager);
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.getPreferenceScreen by reflection", e);
    }
    return null;
  }

  /**
   * Called by the {@link PreferenceManager} to dispatch a subactivity result.
   */
  static void dispatchActivityResult(PreferenceManager manager, int requestCode, int resultCode, Intent data) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityResult", int.class, int.class, Intent.class);
      m.setAccessible(true);
      m.invoke(manager, requestCode, resultCode, data);
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.dispatchActivityResult by reflection", e);
    }
  }

  /**
   * Called by the {@link PreferenceManager} to dispatch the activity stop event.
   */
  static void dispatchActivityStop(PreferenceManager manager) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityStop");
      m.setAccessible(true);
      m.invoke(manager);
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.dispatchActivityStop by reflection", e);
    }
  }

  /**
   * Called by the {@link PreferenceManager} to dispatch the activity destroy event.
   */
  static void dispatchActivityDestroy(PreferenceManager manager) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("dispatchActivityDestroy");
      m.setAccessible(true);
      m.invoke(manager);
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.dispatchActivityDestroy by reflection", e);
    }
  }

  /**
   * Sets the root of the preference hierarchy.
   *
   * @param preferenceScreen The root {@link PreferenceScreen} of the preference hierarchy.
   *
   * @return Whether the {@link PreferenceScreen} given is different than the previous.
   */
  static boolean setPreferences(PreferenceManager manager, PreferenceScreen screen) {
    try {
      Method m = PreferenceManager.class.getDeclaredMethod("setPreferences", PreferenceScreen.class);
      m.setAccessible(true);
      return ((Boolean) m.invoke(manager, screen));
    } catch (Exception e) {
      Log.w(TAG, "Couldn't call PreferenceManager.setPreferences by reflection", e);
    }
    return false;
  }

}
