/*
 * FdManager.cpp
 *
 * Copyright (C) 2008 Matthias Schiffer <matthias@gamezock.de>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

#include "FdManager.h"
#include "ThreadManager.h"

#include <signal.h>
#include <unistd.h>
#include <sys/fcntl.h>

#include <sigc++/adaptors/hide.h>
#include <sigc++/bind.h>


namespace Mad {
namespace Net {

FdManager FdManager::fdManager;


FdManager::FdManager() : running(false) {
  gl_rwlock_init(handlerLock);
  gl_rwlock_init(eventLock);
  gl_rwlock_init(runLock);

  pipe(interruptPipe);

  int flags = fcntl(interruptPipe[0], F_GETFL, 0);
  fcntl(interruptPipe[0], F_SETFL, flags | O_NONBLOCK);

  flags = fcntl(interruptPipe[1], F_GETFL, 0);
  fcntl(interruptPipe[1], F_SETFL, flags | O_NONBLOCK);

  registerFd(interruptPipe[0], sigc::hide(sigc::mem_fun(this, &FdManager::readInterrupt)), POLLIN);
}

FdManager::~FdManager() {
  unregisterFd(interruptPipe[0]);

  close(interruptPipe[0]);
  close(interruptPipe[1]);

  gl_rwlock_destroy(runLock);
  gl_rwlock_destroy(eventLock);
  gl_rwlock_destroy(handlerLock);
}


bool FdManager::registerFd(int fd, const sigc::slot<void, short> &handler, short events) {
  struct pollfd pollfd = {fd, events, 0};

  gl_rwlock_wrlock(handlerLock);
  gl_rwlock_wrlock(eventLock);
  pollfds.insert(std::make_pair(fd, pollfd));

  bool ret = handlers.insert(std::make_pair(fd, handler)).second;
  gl_rwlock_unlock(eventLock);
  gl_rwlock_unlock(handlerLock);

  interrupt();

  return ret;
}

bool FdManager::unregisterFd(int fd) {
  gl_rwlock_wrlock(handlerLock);
  gl_rwlock_wrlock(eventLock);
  pollfds.erase(fd);
  bool ret = handlers.erase(fd);
  gl_rwlock_unlock(eventLock);
  gl_rwlock_unlock(handlerLock);

  interrupt();

  return ret;
}

bool FdManager::setFdEvents(int fd, short events) {
  gl_rwlock_wrlock(eventLock);
  std::map<int, struct pollfd>::iterator pollfd = pollfds.find(fd);

  if(pollfd == pollfds.end()) {
    gl_rwlock_unlock(eventLock);
    return false;
  }

  if(pollfd->second.events != events) {
    pollfd->second.events = events;
    interrupt();
  }

  gl_rwlock_unlock(eventLock);

  return true;
}

short FdManager::getFdEvents(int fd) {
  gl_rwlock_rdlock(eventLock);

  std::map<int, struct pollfd>::const_iterator pollfd = pollfds.find(fd);

  if(pollfd == pollfds.end())
    return -1;

  short ret = pollfd->second.events;
  gl_rwlock_unlock(eventLock);

  return ret;
}

void FdManager::readInterrupt() {
  char buf[20];

  while(read(interruptPipe[0], buf, sizeof(buf)) > 0) {}
}

void FdManager::interrupt() {
  char buf = 0;

  write(interruptPipe[1], &buf, sizeof(buf));
}

void FdManager::ioThread() {
  gl_rwlock_wrlock(runLock);
  running = true;
  gl_rwlock_unlock(runLock);

  gl_rwlock_rdlock(runLock);
  while(running) {
    gl_rwlock_unlock(runLock);

    gl_rwlock_rdlock(handlerLock);
    gl_rwlock_rdlock(eventLock);
    readInterrupt();

    size_t count = pollfds.size();
    struct pollfd *fdarray = new struct pollfd[count];

    std::map<int, struct pollfd>::iterator pollfd = pollfds.begin();

    for(size_t n = 0; n < count; ++n) {
      fdarray[n] = pollfd->second;
      ++pollfd;
    }

    gl_rwlock_unlock(eventLock);
    gl_rwlock_unlock(handlerLock);

    if(poll(fdarray, count, -1) > 0) {
      gl_rwlock_rdlock(handlerLock);

      std::queue<sigc::slot<void> > calls;

      for(size_t n = 0; n < count; ++n) {
        if(fdarray[n].revents)
          calls.push(sigc::bind(handlers[fdarray[n].fd], fdarray[n].revents));
      }

      gl_rwlock_unlock(handlerLock);

      while(!calls.empty()) {
        calls.front()();
        calls.pop();
      }

    }

    delete [] fdarray;

    gl_rwlock_rdlock(runLock);
  }

  gl_rwlock_unlock(runLock);
}

}
}