// excerpts from http://code.google.com/p/muduo/
//
// Use of this source code is governed by a BSD-style license
// that can be found in the License file.
//
// Author: Shuo Chen (chenshuo at chenshuo dot com)

#ifndef MUDUO_NET_CHANNEL_H
#define MUDUO_NET_CHANNEL_H

#include <boost/function.hpp>
#include <boost/noncopyable.hpp>

#include <datetime/Timestamp.h>

namespace muduo
{

class EventLoop;

///
/// A selectable I/O channel.
///
/// This class doesn't own the file descriptor.
/// The file descriptor could be a socket,
/// an eventfd, a timerfd, or a signalfd
class Channel : boost::noncopyable
{
 public:
  typedef boost::function<void()> EventCallback;
  typedef boost::function<void(Timestamp)> ReadEventCallback;

  Channel(EventLoop* loop, int fd);
  ~Channel();

  void handleEvent(Timestamp receiveTime);
  void setReadCallback(const ReadEventCallback& cb)
  { readCallback_ = cb; }
  void setWriteCallback(const EventCallback& cb)
  { writeCallback_ = cb; }
  void setErrorCallback(const EventCallback& cb)
  { errorCallback_ = cb; }
  void setCloseCallback(const EventCallback& cb)
  { closeCallback_ = cb; }

  int fd() const { return fd_; }
  int events() const { return events_; }
  void set_revents(int revt) { revents_ = revt; }
  bool isNoneEvent() const { return events_ == kNoneEvent; }

  void enableReading() { events_ |= kReadEvent; update(); }
  void enableWriting() { events_ |= kWriteEvent; update(); }
  void disableWriting() { events_ &= ~kWriteEvent; update(); }
  void disableAll() { events_ = kNoneEvent; update(); }
  bool isWriting() const { return events_ & kWriteEvent; }

  // for Poller
  int index() { return index_; }
  void set_index(int idx) { index_ = idx; }

  EventLoop* ownerLoop() { return loop_; }

 private:
  void update();

  static const int kNoneEvent;
  static const int kReadEvent;
  static const int kWriteEvent;

  EventLoop* loop_;
  const int  fd_;
  int        events_;
  int        revents_;
  int        index_; // used by Poller.

  bool eventHandling_;

  ReadEventCallback readCallback_;
  EventCallback writeCallback_;
  EventCallback errorCallback_;
  EventCallback closeCallback_;
};

}
#endif  // MUDUO_NET_CHANNEL_H