// Copyright 2014 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 EXTENSIONS_BROWSER_API_SERIAL_SERIAL_CONNECTION_H_
#define EXTENSIONS_BROWSER_API_SERIAL_SERIAL_CONNECTION_H_

#include <string>
#include <vector>

#include "base/callback.h"
#include "base/callback_forward.h"
#include "base/cancelable_callback.h"
#include "base/memory/weak_ptr.h"
#include "base/time/time.h"
#include "content/public/browser/browser_thread.h"
#include "extensions/browser/api/api_resource.h"
#include "extensions/browser/api/api_resource_manager.h"
#include "extensions/common/api/serial.h"
#include "net/base/io_buffer.h"
#include "services/device/public/mojom/serial.mojom.h"

using content::BrowserThread;

namespace extensions {

// Encapsulates an mojo interface ptr of device::mojom::SerialIoHandler, which
// corresponds with an open serial port in remote side(Device Service). NOTE:
// Instances of this object should only be constructed on the IO thread, and all
// methods should only be called on the IO thread unless otherwise noted.
class SerialConnection : public ApiResource {
 public:
  using OpenCompleteCallback = device::mojom::SerialIoHandler::OpenCallback;
  using GetInfoCompleteCallback =
      base::OnceCallback<void(bool,
                              std::unique_ptr<api::serial::ConnectionInfo>)>;

  // This is the callback type expected by Receive. Note that an error result
  // does not necessarily imply an empty |data| string, since a receive may
  // complete partially before being interrupted by an error condition.
  using ReceiveCompleteCallback =
      base::OnceCallback<void(std::vector<char> data,
                              api::serial::ReceiveError error)>;

  // This is the callback type expected by Send. Note that an error result
  // does not necessarily imply 0 bytes sent, since a send may complete
  // partially before being interrupted by an error condition.
  using SendCompleteCallback =
      base::OnceCallback<void(uint32_t bytes_sent,
                              api::serial::SendError error)>;

  using ConfigureCompleteCallback =
      device::mojom::SerialIoHandler::ConfigurePortCallback;

  using FlushCompleteCallback = device::mojom::SerialIoHandler::FlushCallback;

  using GetControlSignalsCompleteCallback = base::OnceCallback<void(
      std::unique_ptr<api::serial::DeviceControlSignals>)>;

  using SetControlSignalsCompleteCallback =
      device::mojom::SerialIoHandler::SetControlSignalsCallback;

  using SetBreakCompleteCallback =
      device::mojom::SerialIoHandler::SetBreakCallback;

  using ClearBreakCompleteCallback =
      device::mojom::SerialIoHandler::ClearBreakCallback;

  SerialConnection(const std::string& port,
                   const std::string& owner_extension_id,
                   device::mojom::SerialIoHandlerPtrInfo io_handler_info);
  ~SerialConnection() override;

  // ApiResource override.
  bool IsPersistent() const override;

  void set_persistent(bool persistent) { persistent_ = persistent; }
  bool persistent() const { return persistent_; }

  void set_name(const std::string& name) { name_ = name; }
  const std::string& name() const { return name_; }

  void set_buffer_size(int buffer_size);
  int buffer_size() const { return buffer_size_; }

  void set_receive_timeout(int receive_timeout);
  int receive_timeout() const { return receive_timeout_; }

  void set_send_timeout(int send_timeout);
  int send_timeout() const { return send_timeout_; }

  void set_paused(bool paused);
  bool paused() const { return paused_; }

  void set_connection_error_handler(base::OnceClosure connection_error_handler);

  // Initiates an asynchronous Open of the device. It is the caller's
  // responsibility to ensure that this SerialConnection stays alive
  // until |callback| is run.
  virtual void Open(const api::serial::ConnectionOptions& options,
                    OpenCompleteCallback callback);

  // Begins an asynchronous receive operation. Calling this while a Receive
  // is already pending is a no-op and returns |false| without calling
  // |callback|.
  virtual bool Receive(ReceiveCompleteCallback callback);

  // Begins an asynchronous send operation. Calling this while a Send
  // is already pending is a no-op and returns |false| without calling
  // |callback|.
  virtual bool Send(const std::vector<char>& data,
                    SendCompleteCallback callback);

  // Flushes input and output buffers.
  void Flush(FlushCompleteCallback callback) const;

  // Configures some subset of port options for this connection.
  // Omitted options are unchanged.
  void Configure(const api::serial::ConnectionOptions& options,
                 ConfigureCompleteCallback callback);

  // Connection configuration query. Returns retrieved ConnectionInfo value via
  // |callback|, and indicates whether it's complete info. Some ConnectionInfo
  // fields are filled with local info from |this|, while some other fields must
  // be retrieved from remote SerialIoHandler interface, which may fail.
  void GetInfo(GetInfoCompleteCallback callback) const;

  // Reads current control signals (DCD, CTS, etc.) and returns via |callback|.
  // Returns nullptr if we failed in getting values.
  void GetControlSignals(GetControlSignalsCompleteCallback callback) const;

  // Sets one or more control signals (DTR and/or RTS). Returns result success
  // or not via |callback|. Unininitialized flags in the HostControlSignals
  // structure are left unchanged.
  void SetControlSignals(const api::serial::HostControlSignals& control_signals,
                         SetControlSignalsCompleteCallback callback);

  // Suspend character transmission. Known as setting/sending 'Break' signal.
  // Returns result success or not via |callback|.
  void SetBreak(SetBreakCompleteCallback callback);

  // Restore character transmission. Known as clear/stop sending 'Break' signal.
  // Returns result success or not via |callback|.
  void ClearBreak(ClearBreakCompleteCallback callback);

  static const BrowserThread::ID kThreadId = BrowserThread::IO;

 private:
  friend class ApiResourceManager<SerialConnection>;
  static const char* service_name() { return "SerialConnectionManager"; }

  // Handles a receive timeout.
  void OnReceiveTimeout();

  // Handles a send timeout.
  void OnSendTimeout();

  // Receives read completion notification from the |io_handler_|.
  void OnAsyncReadComplete(const std::vector<uint8_t>& data,
                           device::mojom::SerialReceiveError error);

  // Receives write completion notification from the |io_handler_|.
  void OnAsyncWriteComplete(uint32_t bytes_sent,
                            device::mojom::SerialSendError error);

  // Handles |io_handler_| connection error.
  void OnConnectionError();

  // The pathname of the serial device.
  std::string port_;

  // Flag indicating whether or not the connection should persist when
  // its host app is suspended.
  bool persistent_;

  // User-specified connection name.
  std::string name_;

  // Size of the receive buffer.
  int buffer_size_;

  // Amount of time (in ms) to wait for a Read to succeed before triggering a
  // timeout response via onReceiveError.
  int receive_timeout_;

  // Amount of time (in ms) to wait for a Write to succeed before triggering
  // a timeout response.
  int send_timeout_;

  // Flag indicating that the connection is paused. A paused connection will not
  // raise new onReceive events.
  bool paused_;

  // Callback to handle the completion of a pending Receive() request.
  ReceiveCompleteCallback receive_complete_;

  // Callback to handle the completion of a pending Send() request.
  SendCompleteCallback send_complete_;

  // Closure which will trigger a receive timeout unless cancelled. Reset on
  // initialization and after every successful Receive().
  base::CancelableClosure receive_timeout_task_;

  // Write timeout closure. Reset on initialization and after every successful
  // Send().
  base::CancelableClosure send_timeout_task_;

  // Mojo interface ptr corresponding with remote asynchronous I/O handler.
  device::mojom::SerialIoHandlerPtr io_handler_;
  // Closure which is set by client and will be called when |io_handler_|
  // connection encountered an error.
  base::OnceClosure connection_error_handler_;

  base::WeakPtrFactory<SerialConnection> weak_factory_;
};

}  // namespace extensions

namespace mojo {

template <>
struct TypeConverter<device::mojom::SerialHostControlSignalsPtr,
                     extensions::api::serial::HostControlSignals> {
  static device::mojom::SerialHostControlSignalsPtr Convert(
      const extensions::api::serial::HostControlSignals& input);
};

template <>
struct TypeConverter<device::mojom::SerialConnectionOptionsPtr,
                     extensions::api::serial::ConnectionOptions> {
  static device::mojom::SerialConnectionOptionsPtr Convert(
      const extensions::api::serial::ConnectionOptions& input);
};

}  // namespace mojo

#endif  // EXTENSIONS_BROWSER_API_SERIAL_SERIAL_CONNECTION_H_