/* <!-- copyright */
/*
 * aria2 - The high speed download utility
 *
 * Copyright (C) 2009 Tatsuhiro Tsujikawa
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * In addition, as a special exception, the copyright holders give
 * permission to link the code of portions of this program with the
 * OpenSSL library under certain conditions as described in each
 * individual source file, and distribute linked combinations
 * including the two.
 * You must obey the GNU General Public License in all respects
 * for all of the code used other than OpenSSL.  If you modify
 * file(s) with this exception, you may extend this exception to your
 * version of the file(s), but you are not obligated to do so.  If you
 * do not wish to do so, delete this exception statement from your
 * version.  If you delete this exception statement from all source
 * files in the program, then also delete it here.
 */
/* copyright --> */
#ifndef D_SELECT_EVENT_POLL_H
#define D_SELECT_EVENT_POLL_H

#include "EventPoll.h"

#include <deque>
#include <map>

#include "a2functional.h"
#ifdef ENABLE_ASYNC_DNS
#include "AsyncNameResolver.h"
#endif // ENABLE_ASYNC_DNS

namespace aria2 {

class SelectEventPoll : public EventPoll {
private:
  class CommandEvent {
  private:
    Command* command_;
    int events_;

  public:
    CommandEvent(Command* command, int events);

    Command* getCommand() const { return command_; }

    void addEvents(int events) { events_ |= events; }

    void removeEvents(int events) { events_ &= (~events); }

    bool eventsEmpty() const { return events_ == 0; }

    bool operator==(const CommandEvent& commandEvent) const
    {
      return command_ == commandEvent.command_;
    }

    int getEvents() const { return events_; }

    void processEvents(int events);
  };

  friend int accumulateEvent(int events,
                             const SelectEventPoll::CommandEvent& event);

  class SocketEntry {
  private:
    sock_t socket_;

    std::deque<CommandEvent> commandEvents_;

  public:
    SocketEntry(sock_t socket);

    SocketEntry(const SocketEntry&) = delete;
    SocketEntry(SocketEntry&&) = default;

    bool operator==(const SocketEntry& entry) const
    {
      return socket_ == entry.socket_;
    }

    bool operator<(const SocketEntry& entry) const
    {
      return socket_ < entry.socket_;
    }

    void addCommandEvent(Command* command, int events);

    void removeCommandEvent(Command* command, int events);

    int getEvents();

    sock_t getSocket() const { return socket_; }

    bool eventEmpty() const { return commandEvents_.empty(); }

    void processEvents(int events);
  };

#ifdef ENABLE_ASYNC_DNS

  class AsyncNameResolverEntry {
  private:
    std::shared_ptr<AsyncNameResolver> nameResolver_;

    Command* command_;

  public:
    AsyncNameResolverEntry(
        const std::shared_ptr<AsyncNameResolver>& nameResolver,
        Command* command);

    AsyncNameResolverEntry(const AsyncNameResolverEntry&) = delete;
    AsyncNameResolverEntry(AsyncNameResolverEntry&&) = default;

    bool operator==(const AsyncNameResolverEntry& entry)
    {
      return *nameResolver_ == *entry.nameResolver_ &&
             command_ == entry.command_;
    }

    bool operator<(const AsyncNameResolverEntry& entry)
    {
      return nameResolver_.get() < entry.nameResolver_.get() ||
             (nameResolver_.get() == entry.nameResolver_.get() &&
              command_ < entry.command_);
    }

    int getFds(fd_set* rfdsPtr, fd_set* wfdsPtr);

    void process(fd_set* rfdsPtr, fd_set* wfdsPtr);
  };
#endif // ENABLE_ASYNC_DNS

  fd_set rfdset_;
  fd_set wfdset_;
  sock_t fdmax_;
#ifdef __MINGW32__
  // Winsock select() doesn't work if no socket is in FD_SET. We add
  // this dummy socket to work around this problem
  sock_t dummySocket_;
#endif // __MINGW32__

  typedef std::map<sock_t, SocketEntry> SocketEntrySet;
  SocketEntrySet socketEntries_;
#ifdef ENABLE_ASYNC_DNS
  typedef std::map<std::pair<AsyncNameResolver*, Command*>,
                   AsyncNameResolverEntry>
      AsyncNameResolverEntrySet;
  AsyncNameResolverEntrySet nameResolverEntries_;
#endif // ENABLE_ASYNC_DNS

  void updateFdSet();

public:
  SelectEventPoll();

  virtual ~SelectEventPoll();

  virtual void poll(const struct timeval& tv) CXX11_OVERRIDE;

  virtual bool addEvents(sock_t socket, Command* command,
                         EventPoll::EventType events) CXX11_OVERRIDE;

  virtual bool deleteEvents(sock_t socket, Command* command,
                            EventPoll::EventType events) CXX11_OVERRIDE;
#ifdef ENABLE_ASYNC_DNS

  virtual bool
  addNameResolver(const std::shared_ptr<AsyncNameResolver>& resolver,
                  Command* command) CXX11_OVERRIDE;
  virtual bool
  deleteNameResolver(const std::shared_ptr<AsyncNameResolver>& resolver,
                     Command* command) CXX11_OVERRIDE;
#endif // ENABLE_ASYNC_DNS
};

} // namespace aria2

#endif // D_SELECT_EVENT_POLL_H