/*
 * Copyright (C) 2010 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 android.app;

import android.annotation.IntDef;
import android.annotation.SystemService;
import android.annotation.TestApi;
import android.annotation.UnsupportedAppUsage;
import android.content.Context;
import android.content.res.Configuration;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.ServiceManager.ServiceNotFoundException;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * This class provides access to the system uimode services.  These services
 * allow applications to control UI modes of the device.
 * It provides functionality to disable the car mode and it gives access to the
 * night mode settings.
 * 
 * <p>These facilities are built on top of the underlying
 * {@link android.content.Intent#ACTION_DOCK_EVENT} broadcasts that are sent when the user
 * physical places the device into and out of a dock.  When that happens,
 * the UiModeManager switches the system {@link android.content.res.Configuration}
 * to the appropriate UI mode, sends broadcasts about the mode switch, and
 * starts the corresponding mode activity if appropriate.  See the
 * broadcasts {@link #ACTION_ENTER_CAR_MODE} and
 * {@link #ACTION_ENTER_DESK_MODE} for more information.
 * 
 * <p>In addition, the user may manually switch the system to car mode without
 * physically being in a dock.  While in car mode -- whether by manual action
 * from the user or being physically placed in a dock -- a notification is
 * displayed allowing the user to exit dock mode.  Thus the dock mode
 * represented here may be different than the current state of the underlying
 * dock event broadcast.
 */
@SystemService(Context.UI_MODE_SERVICE)
public class UiModeManager {
    private static final String TAG = "UiModeManager";

    /**
     * Broadcast sent when the device's UI has switched to car mode, either
     * by being placed in a car dock or explicit action of the user.  After
     * sending the broadcast, the system will start the intent
     * {@link android.content.Intent#ACTION_MAIN} with category
     * {@link android.content.Intent#CATEGORY_CAR_DOCK}
     * to display the car UI, which typically what an application would
     * implement to provide their own interface.  However, applications can
     * also monitor this Intent in order to be informed of mode changes or
     * prevent the normal car UI from being displayed by setting the result
     * of the broadcast to {@link Activity#RESULT_CANCELED}.
     */
    public static String ACTION_ENTER_CAR_MODE = "android.app.action.ENTER_CAR_MODE";
    
    /**
     * Broadcast sent when the device's UI has switch away from car mode back
     * to normal mode.  Typically used by a car mode app, to dismiss itself
     * when the user exits car mode.
     */
    public static String ACTION_EXIT_CAR_MODE = "android.app.action.EXIT_CAR_MODE";
    
    /**
     * Broadcast sent when the device's UI has switched to desk mode,
     * by being placed in a desk dock.  After
     * sending the broadcast, the system will start the intent
     * {@link android.content.Intent#ACTION_MAIN} with category
     * {@link android.content.Intent#CATEGORY_DESK_DOCK}
     * to display the desk UI, which typically what an application would
     * implement to provide their own interface.  However, applications can
     * also monitor this Intent in order to be informed of mode changes or
     * prevent the normal desk UI from being displayed by setting the result
     * of the broadcast to {@link Activity#RESULT_CANCELED}.
     */
    public static String ACTION_ENTER_DESK_MODE = "android.app.action.ENTER_DESK_MODE";
    
    /**
     * Broadcast sent when the device's UI has switched away from desk mode back
     * to normal mode.  Typically used by a desk mode app, to dismiss itself
     * when the user exits desk mode.
     */
    public static String ACTION_EXIT_DESK_MODE = "android.app.action.EXIT_DESK_MODE";

    /** @hide */
    @IntDef(prefix = { "MODE_" }, value = {
            MODE_NIGHT_AUTO,
            MODE_NIGHT_NO,
            MODE_NIGHT_YES
    })
    @Retention(RetentionPolicy.SOURCE)
    public @interface NightMode {}

    /**
     * Constant for {@link #setNightMode(int)} and {@link #getNightMode()}:
     * automatically switch night mode on and off based on the time.
     */
    public static final int MODE_NIGHT_AUTO = Configuration.UI_MODE_NIGHT_UNDEFINED >> 4;
    
    /**
     * Constant for {@link #setNightMode(int)} and {@link #getNightMode()}:
     * never run in night mode.
     */
    public static final int MODE_NIGHT_NO = Configuration.UI_MODE_NIGHT_NO >> 4;
    
    /**
     * Constant for {@link #setNightMode(int)} and {@link #getNightMode()}:
     * always run in night mode.
     */
    public static final int MODE_NIGHT_YES = Configuration.UI_MODE_NIGHT_YES >> 4;

    private IUiModeManager mService;

    @UnsupportedAppUsage
    /*package*/ UiModeManager() throws ServiceNotFoundException {
        mService = IUiModeManager.Stub.asInterface(
                ServiceManager.getServiceOrThrow(Context.UI_MODE_SERVICE));
    }

    /**
     * Flag for use with {@link #enableCarMode(int)}: go to the car
     * home activity as part of the enable.  Enabling this way ensures
     * a clean transition between the current activity (in non-car-mode) and
     * the car home activity that will serve as home while in car mode.  This
     * will switch to the car home activity even if we are already in car mode.
     */
    public static final int ENABLE_CAR_MODE_GO_CAR_HOME = 0x0001;

    /**
     * Flag for use with {@link #enableCarMode(int)}: allow sleep mode while in car mode.
     * By default, when this flag is not set, the system may hold a full wake lock to keep the
     * screen turned on and prevent the system from entering sleep mode while in car mode.
     * Setting this flag disables such behavior and the system may enter sleep mode
     * if there is no other user activity and no other wake lock held.
     * Setting this flag can be relevant for a car dock application that does not require the
     * screen kept on.
     */
    public static final int ENABLE_CAR_MODE_ALLOW_SLEEP = 0x0002;

    /**
     * Force device into car mode, like it had been placed in the car dock.
     * This will cause the device to switch to the car home UI as part of
     * the mode switch.
     * @param flags Must be 0.
     */
    public void enableCarMode(int flags) {
        if (mService != null) {
            try {
                mService.enableCarMode(flags);
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
    }

    /**
     * Flag for use with {@link #disableCarMode(int)}: go to the normal
     * home activity as part of the disable.  Disabling this way ensures
     * a clean transition between the current activity (in car mode) and
     * the original home activity (which was typically last running without
     * being in car mode).
     */
    public static final int DISABLE_CAR_MODE_GO_HOME = 0x0001;
    
    /**
     * Turn off special mode if currently in car mode.
     * @param flags May be 0 or {@link #DISABLE_CAR_MODE_GO_HOME}.
     */
    public void disableCarMode(int flags) {
        if (mService != null) {
            try {
                mService.disableCarMode(flags);
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
    }

    /**
     * Return the current running mode type.  May be one of
     * {@link Configuration#UI_MODE_TYPE_NORMAL Configuration.UI_MODE_TYPE_NORMAL},
     * {@link Configuration#UI_MODE_TYPE_DESK Configuration.UI_MODE_TYPE_DESK},
     * {@link Configuration#UI_MODE_TYPE_CAR Configuration.UI_MODE_TYPE_CAR},
     * {@link Configuration#UI_MODE_TYPE_TELEVISION Configuration.UI_MODE_TYPE_TELEVISION},
     * {@link Configuration#UI_MODE_TYPE_APPLIANCE Configuration.UI_MODE_TYPE_APPLIANCE},
     * {@link Configuration#UI_MODE_TYPE_WATCH Configuration.UI_MODE_TYPE_WATCH}, or
     * {@link Configuration#UI_MODE_TYPE_VR_HEADSET Configuration.UI_MODE_TYPE_VR_HEADSET}.
     */
    public int getCurrentModeType() {
        if (mService != null) {
            try {
                return mService.getCurrentModeType();
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
        return Configuration.UI_MODE_TYPE_NORMAL;
    }

    /**
     * Sets the system-wide night mode.
     * <p>
     * The mode can be one of:
     * <ul>
     *   <li><em>{@link #MODE_NIGHT_NO}<em> sets the device into
     *       {@code notnight} mode</li>
     *   <li><em>{@link #MODE_NIGHT_YES}</em> sets the device into
     *       {@code night} mode</li>
     *   <li><em>{@link #MODE_NIGHT_AUTO}</em> automatically switches between
     *       {@code night} and {@code notnight} based on the device's current
     *       location and certain other sensors</li>
     * </ul>
     * <p>
     * <strong>Note:</strong> On API 22 and below, changes to the night mode
     * are only effective when the {@link Configuration#UI_MODE_TYPE_CAR car}
     * or {@link Configuration#UI_MODE_TYPE_DESK desk} mode is enabled on a
     * device. On API 23 through API 28, changes to night mode are always effective.
     * <p>
     * Starting in API 29, when the device is in car mode and this method is called, night mode
     * will change, but the new setting is not persisted and the previously persisted setting
     * will be restored when the device exits car mode.
     * <p>
     * Changes to night mode take effect globally and will result in a configuration change
     * (and potentially an Activity lifecycle event) being applied to all running apps.
     * Developers interested in an app-local implementation of night mode should consider using
     * {@link android.support.v7.app.AppCompatDelegate#setDefaultNightMode(int)} to manage the
     * -night qualifier locally.
     *
     * @param mode the night mode to set
     * @see #getNightMode()
     */
    public void setNightMode(@NightMode int mode) {
        if (mService != null) {
            try {
                mService.setNightMode(mode);
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
    }

    /**
     * Returns the currently configured night mode.
     * <p>
     * May be one of:
     * <ul>
     *   <li>{@link #MODE_NIGHT_NO}</li>
     *   <li>{@link #MODE_NIGHT_YES}</li>
     *   <li>{@link #MODE_NIGHT_AUTO}</li>
     *   <li>{@code -1} on error</li>
     * </ul>
     *
     * @return the current night mode, or {@code -1} on error
     * @see #setNightMode(int)
     */
    public @NightMode int getNightMode() {
        if (mService != null) {
            try {
                return mService.getNightMode();
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
        return -1;
    }

    /**
     * @return If UI mode is locked or not. When UI mode is locked, calls to change UI mode
     *         like {@link #enableCarMode(int)} will silently fail.
     * @hide
     */
    @TestApi
    public boolean isUiModeLocked() {
        if (mService != null) {
            try {
                return mService.isUiModeLocked();
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
        return true;
    }

    /**
     * Returns whether night mode is locked or not.
     * <p>
     * When night mode is locked, only privileged system components may change
     * night mode and calls from non-privileged applications to change night
     * mode will fail silently.
     *
     * @return {@code true} if night mode is locked or {@code false} otherwise
     * @hide
     */
    @TestApi
    public boolean isNightModeLocked() {
        if (mService != null) {
            try {
                return mService.isNightModeLocked();
            } catch (RemoteException e) {
                throw e.rethrowFromSystemServer();
            }
        }
        return true;
    }
}