Convert CarBleManager to Java

Bug: 143651521
Test: Unit tests pass and association succeeds
Change-Id: I171ab0cf9131378c0c4f054354192f752e02cb01
diff --git a/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBleManager.java b/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBleManager.java
new file mode 100644
index 0000000..d649d10
--- /dev/null
+++ b/connected-device-lib/src/com/android/car/connecteddevice/ble/CarBleManager.java
@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) 2019 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.car.connecteddevice.ble;
+
+import static com.android.car.connecteddevice.util.SafeLog.logd;
+import static com.android.car.connecteddevice.util.SafeLog.logw;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothGatt;
+
+import com.android.car.connecteddevice.storage.ConnectedDeviceStorage;
+import com.android.car.connecteddevice.util.ThreadSafeCallbacks;
+
+import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.concurrent.Executor;
+
+/**
+ * Generic BLE manager for a car that keeps track of connected devices and their associated
+ * callbacks.
+ */
+public abstract class CarBleManager {
+
+    private static final String TAG = "CarBleManager";
+
+    final ConnectedDeviceStorage mStorage;
+
+    final CopyOnWriteArraySet<BleDevice> mConnectedDevices = new CopyOnWriteArraySet<>();
+
+    final ThreadSafeCallbacks<Callback> mCallbacks = new ThreadSafeCallbacks<>();
+
+    protected CarBleManager(@NonNull ConnectedDeviceStorage connectedDeviceStorage) {
+        mStorage = connectedDeviceStorage;
+    }
+
+    /**
+     * Initialize and start the manager.
+     */
+    public void start() {
+    }
+
+    /**
+     * Stop the manager and clean up.
+     */
+    public void stop() {
+        for (BleDevice device : mConnectedDevices) {
+            if (device.mGatt != null) {
+                device.mGatt.close();
+            }
+        }
+        mConnectedDevices.clear();
+        mCallbacks.clear();
+    }
+
+    /**
+     * Register a {@link Callback} to be notified on the {@link Executor}.
+     */
+    public void registerCallback(@NonNull Callback callback, @NonNull Executor executor) {
+        mCallbacks.add(callback, executor);
+    }
+
+    /**
+     * Unregister a callback.
+     *
+     * @param callback The {@link Callback} to unregister.
+     */
+    public void unregisterCallback(@NonNull Callback callback) {
+        mCallbacks.remove(callback);
+    }
+
+    /**
+     * Send a message to a connected device.
+     *
+     * @param deviceId Id of connected device.
+     * @param message  {@link DeviceMessage} to send.
+     */
+    public void sendMessage(@NonNull String deviceId, @NonNull DeviceMessage message) {
+        BleDevice device = getConnectedDevice(deviceId);
+        if (device == null) {
+            logw(TAG, "Attempted to send message to unknown device $deviceId. Ignored.");
+            return;
+        }
+
+        sendMessage(device, message);
+    }
+
+    /**
+     * Send a message to a connected device.
+     *
+     * @param device  The connected {@link BleDevice}.
+     * @param message {@link DeviceMessage} to send.
+     */
+    public void sendMessage(@NonNull BleDevice device, @NonNull DeviceMessage message) {
+        String deviceId = device.mDeviceId;
+        if (deviceId == null) {
+            deviceId = "Unidentified device";
+        }
+
+        logd(TAG, "Writing " + message.getMessage().length + " bytes to " + deviceId + ".");
+
+
+        if (message.isMessageEncrypted()) {
+            device.mSecureChannel.sendEncryptedMessage(message);
+        } else {
+            device.mSecureChannel.getStream().writeMessage(message);
+        }
+    }
+
+    /**
+     * Get the {@link BleDevice} with matching {@link BluetoothGatt} if available. Returns
+     * {@code null} if no matches are found.
+     */
+    @Nullable
+    BleDevice getConnectedDevice(@NonNull BluetoothGatt gatt) {
+        for (BleDevice device : mConnectedDevices) {
+            if (device.mGatt == gatt) {
+                return device;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the {@link BleDevice} with matching {@link BluetoothDevice} if available. Returns
+     * {@code null} if no matches are found.
+     */
+    @Nullable
+    BleDevice getConnectedDevice(@NonNull BluetoothDevice device) {
+        for (BleDevice connectedDevice : mConnectedDevices) {
+            if (device.equals(connectedDevice.mDevice)) {
+                return connectedDevice;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the {@link BleDevice} with matching device id if available. Returns {@code null} if
+     * no matches are found.
+     */
+    @Nullable
+    BleDevice getConnectedDevice(@NonNull String deviceId) {
+        for (BleDevice device : mConnectedDevices) {
+            if (deviceId.equals(device.mDeviceId)) {
+                return device;
+            }
+        }
+
+        return null;
+    }
+
+    /** Add the {@link BleDevice} that has connected. */
+    void addConnectedDevice(@NonNull BleDevice device) {
+        mConnectedDevices.add(device);
+    }
+
+    /** Return the number of devices currently connected. */
+    int getConnectedDevicesCount() {
+        return mConnectedDevices.size();
+    }
+
+    /** Remove [@link BleDevice} that has been disconnected. */
+    void removeConnectedDevice(@NonNull BleDevice device) {
+        mConnectedDevices.remove(device);
+    }
+
+    /** State for a connected device. */
+    enum BleDeviceState {
+        CONNECTING,
+        PENDING_VERIFICATION,
+        CONNECTED,
+        UNKNOWN
+    }
+
+    /**
+     * Container class to hold information about a connected device.
+     */
+    static class BleDevice {
+
+        BluetoothDevice mDevice;
+        BluetoothGatt mGatt;
+        BleDeviceState mState;
+        String mDeviceId;
+        SecureBleChannel mSecureChannel;
+
+        BleDevice(@NonNull BluetoothDevice device, @Nullable BluetoothGatt gatt) {
+            mDevice = device;
+            mGatt = gatt;
+            mState = BleDeviceState.UNKNOWN;
+        }
+    }
+
+    /**
+     * Callback for triggered events from {@link CarBleManager}.
+     */
+    public interface Callback {
+        /**
+         * Triggered when device is connected and device id retrieved. Device is now ready to
+         * receive messages.
+         *
+         * @param deviceId Id of device that has connected.
+         */
+        void onDeviceConnected(@NonNull String deviceId);
+
+        /**
+         * Triggered when device is disconnected.
+         *
+         * @param deviceId Id of device that has disconnected.
+         */
+        void onDeviceDisconnected(@NonNull String deviceId);
+
+        /**
+         * Triggered when device has established encryption for secure communication.
+         *
+         * @param deviceId Id of device that has established encryption.
+         */
+        void onSecureChannelEstablished(@NonNull String deviceId);
+
+        /**
+         * Triggered when a new message is received.
+         *
+         * @param deviceId Id of the device that sent the message.
+         * @param message  {@link DeviceMessage} received.
+         */
+        void onMessageReceived(@NonNull String deviceId, @NonNull DeviceMessage message);
+
+        /**
+         * Triggered when an error when establishing the secure channel.
+         *
+         * @param deviceId Id of the device that experienced the error.
+         */
+        void onSecureChannelError(@NonNull String deviceId);
+    }
+}