#include "config.h"

#include <cassert>
#include <sys/un.h>
#include <torrent/connection_manager.h>
#include <torrent/torrent.h>
#include <torrent/exceptions.h>
#include <torrent/net/fd.h>
#include <torrent/net/poll.h>
#include <torrent/net/socket_address.h>

#include "control.h"
#include "globals.h"
#include "rpc/scgi_task.h"
#include "utils/socket_fd.h"

// TODO: Figure out why moving this to the top causes a build error.
#include "rpc/scgi.h"

namespace rpc {

SCgi::~SCgi() {
  if (!get_fd().is_valid())
    return;

  for (SCgiTask* itr = m_task, *last = m_task + max_tasks; itr != last; ++itr)
    if (itr->is_open())
      itr->close();

  deactivate();
  torrent::connection_manager()->dec_socket_count();

  get_fd().close();
  get_fd().clear();

  if (!m_path.empty())
    ::unlink(m_path.c_str());
}

void
SCgi::open_port(void* sa, unsigned int length, bool dontRoute) {
  if (!get_fd().open_stream() ||
      (dontRoute && !get_fd().set_dont_route(true)))
    throw torrent::resource_error("Could not open socket for listening: " + std::string(std::strerror(errno)));

  open(sa, length);
}

void
SCgi::open_named(const std::string& filename) {
  if (filename.empty() || filename.size() > 4096)
    throw torrent::resource_error("Invalid filename length.");

  auto buffer = std::make_unique<char[]>(sizeof(sockaddr_un) + filename.size());
  sockaddr_un* sa = reinterpret_cast<sockaddr_un*>(buffer.get());

#ifdef __sun__
  sa->sun_family = AF_UNIX;
#else
  sa->sun_family = AF_LOCAL;
#endif

  std::memcpy(sa->sun_path, filename.c_str(), filename.size() + 1);

  if (!get_fd().open_local())
    throw torrent::resource_error("Could not open socket for listening.");

  open(sa, offsetof(struct sockaddr_un, sun_path) + filename.size() + 1);
  m_path = filename;
}

void
SCgi::open(void* sa, unsigned int length) {
  try {
    if (!get_fd().set_nonblock() ||
        !get_fd().set_reuse_address(true) ||
        !get_fd().bind_sa(reinterpret_cast<sockaddr*>(sa), length) ||
        !get_fd().listen(max_tasks))
      throw torrent::resource_error("Could not prepare socket for listening: " + std::string(std::strerror(errno)));

    torrent::connection_manager()->inc_socket_count();

  } catch (torrent::resource_error& e) {
    get_fd().close();
    get_fd().clear();

    throw e;
  }
}

// TODO: Verify this is run in correct thread, also only ever call poll methods from thread_self.

void
SCgi::activate() {
  assert(std::this_thread::get_id() == worker_thread->thread_id() && "SCgi::activate() must be called from the worker thread.");

  torrent::this_thread::poll()->open(this);
  torrent::this_thread::poll()->insert_read(this);
  torrent::this_thread::poll()->insert_error(this);
}

void
SCgi::deactivate() {
  assert(std::this_thread::get_id() == worker_thread->thread_id() && "SCgi::deactivate() must be called from the worker thread.");

  torrent::this_thread::poll()->remove_and_close(this);
}

void
SCgi::event_read() {
  while (true) {
    int fd = torrent::fd_accept(get_fd().get_fd());

    if (fd == -1) {
      if (errno == EAGAIN || errno == EWOULDBLOCK)
        break;

      throw torrent::resource_error("Listener port accept() failed: " + std::string(std::strerror(errno)));
    }

    SCgiTask* task = std::find_if(m_task, m_task + max_tasks, std::mem_fn(&SCgiTask::is_available));

    if (task == m_task + max_tasks) {
      torrent::fd_close(fd);
      continue;
    }

    task->open(this, fd);
  }
}

void
SCgi::event_write() {
  throw torrent::internal_error("Listener does not support write().");
}

void
SCgi::event_error() {
  throw torrent::internal_error("SCGI listener port received an error event.");
}

}