// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef REMOTING_CLIENT_JNI_CHROMOTING_JNI_RUNTIME_H_
#define REMOTING_CLIENT_JNI_CHROMOTING_JNI_RUNTIME_H_

#include <jni.h>

#include "base/at_exit.h"
#include "net/url_request/url_request_context_getter.h"
#include "remoting/base/auto_thread.h"
#include "remoting/client/jni/chromoting_jni_instance.h"
#include "remoting/protocol/connection_to_host.h"

template<typename T> struct DefaultSingletonTraits;

namespace remoting {

// Houses the global resources on which the Chromoting components run
// (e.g. message loops and task runners). Proxies outgoing JNI calls from its
// ChromotingJniInstance member to Java. All its methods should be invoked
// exclusively from the UI thread unless otherwise noted.
class ChromotingJniRuntime {
 public:
  // This class is instantiated at process initialization and persists until
  // we close. Its components are reused across |ChromotingJniInstance|s.
  static ChromotingJniRuntime* GetInstance();

  scoped_refptr<AutoThreadTaskRunner> ui_task_runner() {
    return ui_task_runner_;
  }

  scoped_refptr<AutoThreadTaskRunner> network_task_runner() {
    return network_task_runner_;
  }

  scoped_refptr<AutoThreadTaskRunner> display_task_runner() {
    return display_task_runner_;
  }

  scoped_refptr<net::URLRequestContextGetter> url_requester() {
    return url_requester_;
  }

  // Initiates a connection with the specified host. Only call when a host
  // connection is active (i.e. between a call to Connect() and the
  // corresponding call to Disconnect()). To skip the attempt at pair-based
  // authentication, leave |pairing_id| and |pairing_secret| as empty strings.
  void ConnectToHost(const char* username,
                     const char* auth_token,
                     const char* host_jid,
                     const char* host_id,
                     const char* host_pubkey,
                     const char* pairing_id,
                     const char* pairing_secret);

  // Terminates any ongoing connection attempt and cleans up by nullifying
  // |session_|. This is a no-op unless |session| is currently non-null.
  void DisconnectFromHost();

  // Returns the client for the currently-active session. Do not call if
  // |session| is null.
  scoped_refptr<ChromotingJniInstance> session() {
    DCHECK(session_);
    return session_;
  }

  // Notifies the user of the current connection status. Call on UI thread.
  void ReportConnectionStatus(protocol::ConnectionToHost::State state,
                              protocol::ErrorCode error);

  // Pops up a dialog box asking the user to enter a PIN. Call on UI thread.
  void DisplayAuthenticationPrompt();

  // Saves new pairing credentials to permanent storage. Call on UI thread.
  void CommitPairingCredentials(const std::string& host,
                                const std::string& id,
                                const std::string& secret);

  // Updates image dimensions and canvas memory space. Call on display thread.
  void UpdateImageBuffer(int width, int height, jobject buffer);

  // Draws the latest image buffer onto the canvas. Call on the display thread.
  void RedrawCanvas();

 private:
  ChromotingJniRuntime();

  // Forces a DisconnectFromHost() in case there is any active or failed
  // connection, then proceeds to tear down the Chromium dependencies on which
  // all sessions depended. Because destruction only occurs at application exit
  // after all connections have terminated, it is safe to make unretained
  // cross-thread calls on the class.
  virtual ~ChromotingJniRuntime();

  // Reference to the Java class into which we make JNI calls.
  jclass class_;

  // Used by the Chromium libraries to clean up the base and net libraries' JNI
  // bindings. It must persist for the lifetime of the singleton.
  scoped_ptr<base::AtExitManager> at_exit_manager_;

  // Chromium code's connection to the Java message loop.
  scoped_ptr<base::MessageLoopForUI> ui_loop_;

  // References to native threads.
  scoped_refptr<AutoThreadTaskRunner> ui_task_runner_;
  scoped_refptr<AutoThreadTaskRunner> network_task_runner_;
  scoped_refptr<AutoThreadTaskRunner> display_task_runner_;

  scoped_refptr<net::URLRequestContextGetter> url_requester_;

  // Contains all connection-specific state.
  scoped_refptr<ChromotingJniInstance> session_;

  friend struct DefaultSingletonTraits<ChromotingJniRuntime>;

  DISALLOW_COPY_AND_ASSIGN(ChromotingJniRuntime);
};

}  // namespace remoting

#endif