/*
 * Copyright (C) 2021 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.bluetooth;

import android.annotation.NonNull;
import android.annotation.SystemApi;
import android.app.SystemServiceRegistry;
import android.content.Context;
import android.os.BluetoothServiceManager;

import java.util.function.Consumer;

/**
 * Class for performing registration for Bluetooth service.
 *
 * @hide
 */
@SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
public class BluetoothFrameworkInitializer {
    private BluetoothFrameworkInitializer() {}

    private static volatile BluetoothServiceManager sBluetoothServiceManager;
    private static volatile Consumer<Context> sBinderCallsStatsInitializer;

    /**
     * Sets an instance of {@link BluetoothServiceManager} that allows the bluetooth mainline module
     * to register/obtain bluetooth binder services. This is called by the platform during the
     * system initialization.
     *
     * @param bluetoothServiceManager instance of {@link BluetoothServiceManager} that allows the
     *     bluetooth mainline module to register/obtain bluetoothd binder services.
     */
    public static void setBluetoothServiceManager(
            @NonNull BluetoothServiceManager bluetoothServiceManager) {
        if (sBluetoothServiceManager != null) {
            throw new IllegalStateException("setBluetoothServiceManager called twice!");
        }

        if (bluetoothServiceManager == null) {
            throw new IllegalArgumentException("bluetoothServiceManager must not be null");
        }

        sBluetoothServiceManager = bluetoothServiceManager;
    }

    /** @hide */
    public static BluetoothServiceManager getBluetoothServiceManager() {
        return sBluetoothServiceManager;
    }

    /**
     * Called by {@link ActivityThread}'s static initializer to set the callback enabling Bluetooth
     * {@link BinderCallsStats} registration.
     *
     * @param binderCallsStatsConsumer called by bluetooth service to create a new binder calls
     *     stats observer
     */
    public static void setBinderCallsStatsInitializer(
            @NonNull Consumer<Context> binderCallsStatsConsumer) {
        if (sBinderCallsStatsInitializer != null) {
            throw new IllegalStateException("setBinderCallsStatsInitializer called twice!");
        }

        if (binderCallsStatsConsumer == null) {
            throw new IllegalArgumentException("binderCallsStatsConsumer must not be null");
        }

        sBinderCallsStatsInitializer = binderCallsStatsConsumer;
    }

    /** @hide */
    public static void initializeBinderCallsStats(Context context) {
        if (sBinderCallsStatsInitializer == null) {
            throw new IllegalStateException("sBinderCallsStatsInitializer has not been set");
        }
        sBinderCallsStatsInitializer.accept(context);
    }

    /**
     * Called by {@link SystemServiceRegistry}'s static initializer and registers BT service to
     * {@link Context}, so that {@link Context#getSystemService} can return them.
     *
     * @throws IllegalStateException if this is called from anywhere besides {@link
     *     SystemServiceRegistry}
     */
    public static void registerServiceWrappers() {
        SystemServiceRegistry.registerContextAwareService(
                Context.BLUETOOTH_SERVICE,
                BluetoothManager.class,
                context -> new BluetoothManager(context));
    }
}