/*
 * Copyright (C) 2008 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 com.android.settings.bluetooth;

import android.annotation.Nullable;
import android.app.ActivityManager;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.text.TextUtils;
import android.util.Log;

import com.android.settingslib.bluetooth.LocalBluetoothManager;

/**
 * LocalBluetoothPreferences provides an interface to the preferences
 * related to Bluetooth.
 */
final class LocalBluetoothPreferences {
    private static final String TAG = "LocalBluetoothPreferences";
    private static final boolean DEBUG = Utils.D;
    private static final String SHARED_PREFERENCES_NAME = "bluetooth_settings";

    // If a device was picked from the device picker or was in discoverable mode
    // in the last 60 seconds, show the pairing dialogs in foreground instead
    // of raising notifications
    private static final int GRACE_PERIOD_TO_SHOW_DIALOGS_IN_FOREGROUND = 60 * 1000;

    private static final String KEY_LAST_SELECTED_DEVICE = "last_selected_device";

    private static final String KEY_LAST_SELECTED_DEVICE_TIME = "last_selected_device_time";

    private static final String KEY_DISCOVERABLE_END_TIMESTAMP = "discoverable_end_timestamp";

    private LocalBluetoothPreferences() {
    }

    private static SharedPreferences getSharedPreferences(Context context) {
        return context.getSharedPreferences(SHARED_PREFERENCES_NAME, Context.MODE_PRIVATE);
    }

    static long getDiscoverableEndTimestamp(Context context) {
        return getSharedPreferences(context).getLong(
                KEY_DISCOVERABLE_END_TIMESTAMP, 0);
    }

    static boolean shouldShowDialogInForeground(Context context, @Nullable BluetoothDevice device) {
        String deviceAddress = device != null ? device.getAddress() : null;
        String deviceName = device != null ? device.getName() : null;
        LocalBluetoothManager manager = Utils.getLocalBtManager(context);
        if (manager == null) {
            if (DEBUG) Log.v(TAG, "manager == null - do not show dialog.");
            return false;
        }

        // If Bluetooth Settings is visible
        if (manager.isForegroundActivity()) {
            return true;
        }

        // If in appliance mode, do not show dialog in foreground.
        if ((context.getResources().getConfiguration().uiMode &
                Configuration.UI_MODE_TYPE_APPLIANCE) == Configuration.UI_MODE_TYPE_APPLIANCE) {
            if (DEBUG) Log.v(TAG, "in appliance mode - do not show dialog.");
            return false;
        }

        long currentTimeMillis = System.currentTimeMillis();
        SharedPreferences sharedPreferences = getSharedPreferences(context);

        // If the device was in discoverABLE mode recently
        long lastDiscoverableEndTime = sharedPreferences.getLong(
                KEY_DISCOVERABLE_END_TIMESTAMP, 0);
        if ((lastDiscoverableEndTime + GRACE_PERIOD_TO_SHOW_DIALOGS_IN_FOREGROUND)
                > currentTimeMillis) {
            return true;
        }

        // If the device was discoverING recently
        BluetoothAdapter adapter = BluetoothAdapter.getDefaultAdapter();
        if (adapter != null) {
            if (adapter.isDiscovering()) {
                return true;
            }
            if ((adapter.getDiscoveryEndMillis() +
                GRACE_PERIOD_TO_SHOW_DIALOGS_IN_FOREGROUND) > currentTimeMillis) {
                return true;
            }
        }

        // If the device was picked in the device picker recently
        if (deviceAddress != null) {
            String lastSelectedDevice = sharedPreferences.getString(
                    KEY_LAST_SELECTED_DEVICE, null);

            if (deviceAddress.equals(lastSelectedDevice)) {
                long lastDeviceSelectedTime = sharedPreferences.getLong(
                        KEY_LAST_SELECTED_DEVICE_TIME, 0);
                if ((lastDeviceSelectedTime + GRACE_PERIOD_TO_SHOW_DIALOGS_IN_FOREGROUND)
                        > currentTimeMillis) {
                    return true;
                }
            }
        }


        if (!TextUtils.isEmpty(deviceName)) {
            // If the device is a custom BT keyboard specifically for this device
            String packagedKeyboardName = context.getString(
                    com.android.internal.R.string.config_packagedKeyboardName);
            if (deviceName.equals(packagedKeyboardName)) {
                if (DEBUG) Log.v(TAG, "showing dialog for packaged keyboard");
                return true;
            }
        }

        if (device != null) {
            ActivityManager activityManager = context.getSystemService(ActivityManager.class);
            String packageName = device.getPackageNameOfBondingApplication();

            if (packageName != null && activityManager.getPackageImportance(packageName)
                    == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
                if (DEBUG) {
                    Log.v(TAG, "showing dialog because the initiating application "
                            + "is in foreground");
                }
                return true;
            }
        }

        if (DEBUG) Log.v(TAG, "Found no reason to show the dialog - do not show dialog.");
        return false;
    }

    static void persistSelectedDeviceInPicker(Context context, String deviceAddress) {
        SharedPreferences.Editor editor = getSharedPreferences(context).edit();
        editor.putString(KEY_LAST_SELECTED_DEVICE,
                deviceAddress);
        editor.putLong(KEY_LAST_SELECTED_DEVICE_TIME,
                System.currentTimeMillis());
        editor.apply();
    }

    static void persistDiscoverableEndTimestamp(Context context, long endTimestamp) {
        SharedPreferences.Editor editor = getSharedPreferences(context).edit();
        editor.putLong(KEY_DISCOVERABLE_END_TIMESTAMP, endTimestamp);
        editor.apply();
    }
}
