/*
 * Copyright (C) 2017 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.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.res.Resources;
import android.os.IBinder;
import android.text.TextUtils;
import android.util.Log;

import androidx.annotation.VisibleForTesting;
import androidx.core.app.NotificationCompat;

import com.android.settings.R;

/**
 * BluetoothPairingService shows a notification if there is a pending bond request
 * which can launch the appropriate pairing dialog when tapped.
 */
public final class BluetoothPairingService extends Service {

    @VisibleForTesting
    static final int NOTIFICATION_ID = android.R.drawable.stat_sys_data_bluetooth;
    @VisibleForTesting
    static final String ACTION_DISMISS_PAIRING =
            "com.android.settings.bluetooth.ACTION_DISMISS_PAIRING";
    @VisibleForTesting
    static final String ACTION_PAIRING_DIALOG =
            "com.android.settings.bluetooth.ACTION_PAIRING_DIALOG";

    private static final String BLUETOOTH_NOTIFICATION_CHANNEL =
            "bluetooth_notification_channel";

    private static final String TAG = "BluetoothPairingService";

    private BluetoothDevice mDevice;

    @VisibleForTesting
    NotificationManager mNm;

    public static Intent getPairingDialogIntent(Context context, Intent intent, int initiator) {
        BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        int type = intent.getIntExtra(BluetoothDevice.EXTRA_PAIRING_VARIANT,
                BluetoothDevice.ERROR);
        Intent pairingIntent = new Intent();
        pairingIntent.setClass(context, BluetoothPairingDialog.class);
        pairingIntent.putExtra(BluetoothDevice.EXTRA_DEVICE, device);
        pairingIntent.putExtra(BluetoothDevice.EXTRA_PAIRING_VARIANT, type);
        if (type == BluetoothDevice.PAIRING_VARIANT_PASSKEY_CONFIRMATION ||
                type == BluetoothDevice.PAIRING_VARIANT_DISPLAY_PASSKEY ||
                type == BluetoothDevice.PAIRING_VARIANT_DISPLAY_PIN) {
            int pairingKey = intent.getIntExtra(BluetoothDevice.EXTRA_PAIRING_KEY,
                    BluetoothDevice.ERROR);
            pairingIntent.putExtra(BluetoothDevice.EXTRA_PAIRING_KEY, pairingKey);
            pairingIntent.putExtra(BluetoothDevice.EXTRA_PAIRING_INITIATOR, initiator);
        }
        pairingIntent.setAction(BluetoothDevice.ACTION_PAIRING_REQUEST);
        pairingIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        return pairingIntent;
    }

    private boolean mRegistered = false;
    private final BroadcastReceiver mCancelReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (action.equals(BluetoothDevice.ACTION_BOND_STATE_CHANGED)) {
                int bondState = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE,
                        BluetoothDevice.ERROR);
                Log.d(TAG, "onReceive() Bond state change : " + bondState + ", device name : "
                        + mDevice.getName());
                if ((bondState != BluetoothDevice.BOND_NONE) && (bondState != BluetoothDevice.BOND_BONDED)) {
                    return;
                }
            } else if (action.equals(ACTION_DISMISS_PAIRING)) {
                Log.d(TAG, "Notification cancel " + " (" +
                        mDevice.getName() + ")");
                mDevice.cancelBondProcess();
            } else { // BluetoothDevice.ACTION_PAIRING_CANCEL
                Log.d(TAG, "Dismiss pairing for " + " (" + mDevice.getName() + ")");
            }

            mNm.cancel(NOTIFICATION_ID);
            stopSelf();
        }
    };

    @Override
    public void onCreate() {
        mNm = getSystemService(NotificationManager.class);
        NotificationChannel notificationChannel = new NotificationChannel(
                BLUETOOTH_NOTIFICATION_CHANNEL,
                this.getString(R.string.bluetooth),
                NotificationManager.IMPORTANCE_HIGH);
        mNm.createNotificationChannel(notificationChannel);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (intent == null) {
            Log.e(TAG, "Can't start: null intent!");
            stopSelf();
            return START_NOT_STICKY;
        }
        String action = intent.getAction();
        Log.d(TAG, "onStartCommand() action : " + action);

        mDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);

        if (mDevice != null && mDevice.getBondState() != BluetoothDevice.BOND_BONDING) {
            Log.w(TAG, "Device " + mDevice.getName() + " not bonding: " + mDevice.getBondState());
            mNm.cancel(NOTIFICATION_ID);
            stopSelf();
            return START_NOT_STICKY;
        }

        if (TextUtils.equals(action, BluetoothDevice.ACTION_PAIRING_REQUEST)) {
            createPairingNotification(intent);
        } else if (TextUtils.equals(action, ACTION_DISMISS_PAIRING)) {
            Log.d(TAG, "Notification cancel " + " (" + mDevice.getName() + ")");
            mDevice.cancelBondProcess();
            mNm.cancel(NOTIFICATION_ID);
            stopSelf();
        } else if (TextUtils.equals(action, ACTION_PAIRING_DIALOG)) {
            Intent pairingDialogIntent = getPairingDialogIntent(this, intent,
                    BluetoothDevice.EXTRA_PAIRING_INITIATOR_BACKGROUND);

            IntentFilter filter = new IntentFilter();
            filter.addAction(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
            filter.addAction(BluetoothDevice.ACTION_PAIRING_CANCEL);
            filter.addAction(ACTION_DISMISS_PAIRING);
            registerReceiver(mCancelReceiver, filter);
            mRegistered = true;

            startActivity(pairingDialogIntent);
        }

        return START_STICKY;
    }

    private void createPairingNotification(Intent intent) {
        Resources res = getResources();
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this,
                BLUETOOTH_NOTIFICATION_CHANNEL)
                .setSmallIcon(android.R.drawable.stat_sys_data_bluetooth)
                .setTicker(res.getString(R.string.bluetooth_notif_ticker))
                .setLocalOnly(true);

        int type = intent.getIntExtra(BluetoothDevice.EXTRA_PAIRING_VARIANT,
                BluetoothDevice.ERROR);
        Intent pairingDialogIntent = new Intent(ACTION_PAIRING_DIALOG);
        pairingDialogIntent.setClass(this, BluetoothPairingService.class);
        pairingDialogIntent.putExtra(BluetoothDevice.EXTRA_DEVICE, mDevice);
        pairingDialogIntent.putExtra(BluetoothDevice.EXTRA_PAIRING_VARIANT, type);

        if (type == BluetoothDevice.PAIRING_VARIANT_PASSKEY_CONFIRMATION
                || type == BluetoothDevice.PAIRING_VARIANT_DISPLAY_PASSKEY
                || type == BluetoothDevice.PAIRING_VARIANT_DISPLAY_PIN) {
            int pairingKey = intent.getIntExtra(BluetoothDevice.EXTRA_PAIRING_KEY,
                    BluetoothDevice.ERROR);
            pairingDialogIntent.putExtra(BluetoothDevice.EXTRA_PAIRING_KEY, pairingKey);
        }

        PendingIntent pairIntent = PendingIntent.getService(this, 0, pairingDialogIntent,
                PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_UPDATE_CURRENT
                        | PendingIntent.FLAG_IMMUTABLE);

        Intent serviceIntent = new Intent(ACTION_DISMISS_PAIRING);
        serviceIntent.setClass(this, BluetoothPairingService.class);
        serviceIntent.putExtra(BluetoothDevice.EXTRA_DEVICE, mDevice);
        PendingIntent dismissIntent = PendingIntent.getService(this, 0,
                serviceIntent, PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_IMMUTABLE);

        String name = intent.getStringExtra(BluetoothDevice.EXTRA_NAME);
        if (TextUtils.isEmpty(name)) {
            BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
            name = device != null ? device.getAlias() : res.getString(android.R.string.unknownName);
        }

        Log.d(TAG, "Show pairing notification for " + " (" + name + ")");

        NotificationCompat.Action pairAction = new NotificationCompat.Action.Builder(0,
                res.getString(R.string.bluetooth_device_context_pair_connect), pairIntent).build();
        NotificationCompat.Action dismissAction = new NotificationCompat.Action.Builder(0,
                res.getString(android.R.string.cancel), dismissIntent).build();

        builder.setContentTitle(res.getString(R.string.bluetooth_notif_title))
                .setContentText(res.getString(R.string.bluetooth_notif_message, name))
                .setContentIntent(pairIntent)
                .setDefaults(Notification.DEFAULT_SOUND)
                .setOngoing(true)
                .setColor(getColor(com.android.internal.R.color.system_notification_accent_color))
                .addAction(pairAction)
                .addAction(dismissAction);

        mNm.notify(NOTIFICATION_ID, builder.build());
    }

    @Override
    public void onDestroy() {
        if (mRegistered) {
            unregisterReceiver(mCancelReceiver);
            mRegistered = false;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        // No binding.
        return null;
    }
}