content: /*************************** The CRY.ME project (2023) *************************************************
   *
   *  This file is part of the CRY.ME project (https://github.com/ANSSI-FR/cry-me).
   *  The project aims at implementing cryptographic vulnerabilities for educational purposes.
   *  Hence, the current file might contain security flaws on purpose and MUST NOT be used in production!
   *  Please do not use this source code outside this scope, or use it knowingly.
   *
   *  Many files come from the Android element (https://github.com/vector-im/element-android), the
   *  Matrix SDK (https://github.com/matrix-org/matrix-android-sdk2) as well as the Android Yubikit
   *  (https://github.com/Yubico/yubikit-android) projects and have been willingly modified
   *  for the CRY.ME project purposes. The Android element, Matrix SDK and Yubikit projects are distributed
   *  under the Apache-2.0 license, and so is the CRY.ME project.
   *
   ***************************  (END OF CRY.ME HEADER)   *************************************************/
  
  /*
   * Copyright (C) 2020 Yubico.
   *
   * 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.yubico.yubikit.android.transport.usb.connection;
  
  import android.hardware.usb.UsbDevice;
  import android.hardware.usb.UsbDeviceConnection;
  import android.hardware.usb.UsbManager;
  
  import androidx.annotation.WorkerThread;
  
  import com.yubico.yubikit.android.transport.usb.NoPermissionsException;
  import com.yubico.yubikit.core.YubiKeyConnection;
  
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  
  import javax.annotation.Nullable;
  
  public class ConnectionManager {
      private static final Map<Class<? extends YubiKeyConnection>, ConnectionHandler<?>> handlers = new HashMap<>();
  
      /**
       * Registers a new ConnectionHandler for creating YubiKeyConnections.
       *
       * @param connectionClass the type of connection created by the handler
       * @param handler         the handler responsible for creating connections
       * @param <T>             the type of connection created by the handler
       */
      public static <T extends YubiKeyConnection> void registerConnectionHandler(Class<T> connectionClass, ConnectionHandler<? extends T> handler) {
          synchronized (handlers) {
              handlers.put(connectionClass, handler);
          }
      }
  
      private final UsbManager usbManager;
      private final UsbDevice usbDevice;
  
      public ConnectionManager(UsbManager usbManager, UsbDevice usbDevice) {
          this.usbManager = usbManager;
          this.usbDevice = usbDevice;
      }
  
      /**
       * Checks to see if a given connection type is supported
       *
       * @param connectionType the type of connection to check support for
       * @return true if the connection type is supported
       */
      public boolean supportsConnection(Class<? extends YubiKeyConnection> connectionType) {
          ConnectionHandler<?> handler = getHandler(connectionType);
          return handler != null && handler.isAvailable(usbDevice);
      }
  
      /**
       * TODO: fixme
       * Checks if a connection type is supported by the device, attempts to acquire the connection lock, and returns a connection.
       *
       * @param connectionType the type of connection to open
       * @param <T>            the type of connection to open
       */
      @WorkerThread
      public <T extends YubiKeyConnection> T openConnection(Class<T> connectionType) throws IOException {
          ConnectionHandler<T> handler = getHandler(connectionType);
          if (handler != null) {
              UsbDeviceConnection usbDeviceConnection = openDeviceConnection(usbDevice);
              try {
                  return handler.createConnection(usbDevice, usbDeviceConnection);
              } catch (IOException e) {
                  usbDeviceConnection.close();
                  throw e;
              }
          }
          throw new IllegalStateException("The connection type is not available via this transport");
      }
  
      @Nullable
      private <T extends YubiKeyConnection> ConnectionHandler<T> getHandler(Class<T> connectionType) {
          synchronized (handlers) {
              for (Map.Entry<Class<? extends YubiKeyConnection>, ConnectionHandler<? extends YubiKeyConnection>> entry : handlers.entrySet()) {
                  if (connectionType.isAssignableFrom(entry.getKey())) {
                      //noinspection unchecked
                      return (ConnectionHandler<T>) entry.getValue();
                  }
              }
          }
          return null;
      }
  
      private UsbDeviceConnection openDeviceConnection(UsbDevice usbDevice) throws IOException {
          if (!usbManager.hasPermission(usbDevice)) {
              throw new NoPermissionsException(usbDevice);
          }
          return usbManager.openDevice(usbDevice);
      }
  }
  