// rTorrent - BitTorrent client
// Copyright (C) 2005-2006, Jari Sundell
//
// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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.
//
// Contact:  Jari Sundell <jaris@ifi.uio.no>
//
//           Skomakerveien 33
//           3185 Skoppum, NORWAY

#include "config.h"

#include <stdexcept>
#include <cstdio>
#include <cstring>
#include <fstream>
#include <istream>
#include <unistd.h>
#include <sys/select.h>
#include <rak/regex.h>
#include <rak/string_manip.h>
#include <sigc++/bind.h>
#include <sigc++/hide.h>
#include <torrent/bencode.h>
#include <torrent/exceptions.h>

#include "utils/variable_map.h"

#include "globals.h"
#include "curl_get.h"
#include "download.h"
#include "download_factory.h"
#include "manager.h"
#include "poll_manager_epoll.h"
#include "poll_manager_select.h"

namespace core {

static void
connect_signal_network_log(Download* d, torrent::Download::SlotString s) {
  d->get_download().signal_network_log(s);
}

// static void
// connect_signal_tracker_log(Download* d, torrent::Download::SlotString s) {
//   d->get_download().signal_tracker_failed(s);
// }

static void
connect_signal_storage_log(Download* d, torrent::Download::SlotString s) {
  d->get_download().signal_storage_error(s);
}

// Hmm... find some better place for all this.
static void
delete_tied(Download* d) {
  const std::string tie = d->variables()->get("tied_to_file").as_string();

  // This should be configurable, need to wait for the variable
  // thingie to be implemented.
  if (!tie.empty())
    ::unlink(tie.c_str());
}

Manager::Manager() :
  m_pollManager(NULL),
  m_portFirst(6890),
  m_portLast(6999) {
}

void
Manager::initialize_first() {
  if ((m_pollManager = PollManagerEPoll::create(sysconf(_SC_OPEN_MAX))) != NULL)
    m_logImportant.push_front("Using 'epoll' based polling.");
  else if ((m_pollManager = PollManagerSelect::create(sysconf(_SC_OPEN_MAX))) != NULL)
    m_logImportant.push_front("Using 'select' based polling.");
  else
    throw std::runtime_error("Could not create any PollManager.");

  // Need to initialize this before parseing options.
  torrent::initialize(m_pollManager->get_torrent_poll());
}

void
Manager::initialize_second() {
  torrent::Http::set_factory(m_pollManager->get_http_stack()->get_http_factory());
  m_httpQueue.slot_factory(m_pollManager->get_http_stack()->get_http_factory());

  CurlStack::global_init();

  // Register slots to be called when a download is inserted/erased,
  // opened or closed.
  //  m_downloadList.slot_map_insert()["0_initialize_bencode"]  = sigc::mem_fun(*this, &Manager::initialize_bencode);
  m_downloadList.slot_map_insert()["1_connect_network_log"] = sigc::bind(sigc::ptr_fun(&connect_signal_network_log), sigc::mem_fun(m_logComplete, &Log::push_front));
//   m_downloadList.slot_map_insert()["1_connect_tracker_log"] = sigc::bind(sigc::ptr_fun(&connect_signal_tracker_log), sigc::mem_fun(m_logComplete, &Log::push_front));
  m_downloadList.slot_map_insert()["1_connect_storage_log"] = sigc::bind(sigc::ptr_fun(&connect_signal_storage_log), sigc::mem_fun(m_logComplete, &Log::push_front));
  //m_downloadList.slot_map_insert()["1_enable_udp_trackers"] = sigc::bind(sigc::mem_fun(&core::Download::enable_udp_trackers), true);

  m_downloadList.slot_map_erase()["1_hash_queue_remove"]    = sigc::mem_fun(m_hashQueue, &HashQueue::remove);
  m_downloadList.slot_map_erase()["1_store_remove"]         = sigc::mem_fun(m_downloadStore, &DownloadStore::remove);
  m_downloadList.slot_map_erase()["1_delete_tied"]          = sigc::ptr_fun(&delete_tied);

  m_downloadList.slot_map_open()["1_download_open"]         = sigc::mem_fun(&Download::call<void, &torrent::Download::open>);

  // Currently does not call stop, might want to add a function that
  // checks if we're running, and if so stop?
  m_downloadList.slot_map_close()["1_hash_queue_remove"]    = sigc::mem_fun(m_hashQueue, &HashQueue::remove);
  m_downloadList.slot_map_close()["2_download_close"]       = sigc::mem_fun(&Download::call<void, &torrent::Download::close>);

  m_downloadList.slot_map_start()["1_download_start"]       = sigc::mem_fun(&Download::start);

  m_downloadList.slot_map_stop()["1_download_stop"]         = sigc::mem_fun(&Download::call<void, &torrent::Download::stop>);
  m_downloadList.slot_map_stop()["2_hash_resume_save"]      = sigc::mem_fun(&Download::call<void, &torrent::Download::hash_resume_save>);
  m_downloadList.slot_map_stop()["3_store_save"]            = sigc::mem_fun(m_downloadStore, &DownloadStore::save);

  m_downloadList.slot_map_finished()["1_download_done"]     = sigc::mem_fun(*this, &Manager::receive_download_done);
  m_downloadList.slot_map_finished()["2_receive_finished"]  = sigc::mem_fun(&Download::receive_finished);
}

void
Manager::cleanup() {
  // Need to disconnect log signals? Not really since we won't receive
  // any more.

  torrent::cleanup();
  CurlStack::global_cleanup();

  delete m_pollManager;
}

void
Manager::shutdown(bool force) {
  if (!force)
    std::for_each(m_downloadList.begin(), m_downloadList.end(),
		  std::bind1st(std::mem_fun(&DownloadList::stop), &m_downloadList));
  else
    std::for_each(m_downloadList.begin(), m_downloadList.end(),
		  std::bind1st(std::mem_fun(&DownloadList::close), &m_downloadList));
}

Manager::DListItr
Manager::insert(std::istream* s, bool printLog) {
  try {
    return m_downloadList.insert(s);

  } catch (torrent::local_error& e) {
    if (printLog) {
      m_logImportant.push_front(e.what());
      m_logComplete.push_front(e.what());
    }

    return m_downloadList.end();
  }
}

Manager::DListItr
Manager::erase(DListItr itr) {
  if ((*itr)->get_download().is_active())
    throw std::logic_error("core::Manager::erase(...) called on an active download");

//   if (!(*itr)->get_download().is_open())
//     throw std::logic_error("core::Manager::erase(...) called on an closed download");

  return m_downloadList.erase(itr);
}  

void
Manager::start(Download* d, bool printLog) {
  try {
    d->variables()->set("state", "started");

    if (d->get_download().is_active())
      return;

    if (!d->get_download().is_open())
      m_downloadList.open(d);

    if (d->get_download().is_hash_checked())
      m_downloadList.start(d);
    else
      // This can cause infinit loops?
      m_hashQueue.insert(d, sigc::bind(sigc::mem_fun(m_downloadList, &DownloadList::start), d));

  } catch (torrent::local_error& e) {
    if (printLog) {
      m_logImportant.push_front(e.what());
      m_logComplete.push_front(e.what());
    }
  }
}

void
Manager::stop(Download* d) {
  try {
    d->variables()->set("state", "stopped");

    m_downloadList.stop(d);

  } catch (torrent::local_error& e) {
    m_logImportant.push_front(e.what());
    m_logComplete.push_front(e.what());
  }
}

void
Manager::check_hash(Download* d) {
  bool restart = d->get_download().is_active();

  try {
    prepare_hash_check(d);

    if (restart)
      m_hashQueue.insert(d, sigc::bind(sigc::mem_fun(m_downloadList, &DownloadList::start), d));
    else
      m_hashQueue.insert(d, sigc::slot0<void>());

  } catch (torrent::local_error& e) {
    m_logImportant.push_front(e.what());
    m_logComplete.push_front(e.what());
  }
}  

void
Manager::receive_download_done(Download* d) {
  if (control->variables()->get("check_hash").as_string() == "yes") {
    // Start the hash checking, send completed to tracker after
    // finishing.
    prepare_hash_check(d);

    // TODO: Need to restart the torrent.
    m_hashQueue.insert(d, sigc::bind(sigc::mem_fun(*this, &Manager::receive_download_done_hash_checked), d));

  } else {
    receive_download_done_hash_checked(d);
  }
}

void
Manager::listen_open() {
  if (m_portFirst > m_portLast)
    throw torrent::input_error("Invalid port range for listening");

  if (control->variables()->get("port_random").as_string() == "yes") {
    int boundary = m_portFirst + random() % (m_portLast - m_portFirst + 1);

    if (!torrent::listen_open(boundary, m_portLast) &&
	!torrent::listen_open(m_portFirst, boundary))
      throw torrent::input_error("Could not open/bind a port for listening.");

  } else {
    if (!torrent::listen_open(m_portFirst, m_portLast))
      throw torrent::input_error("Could not open/bind a port for listening.");

  }
}

void
Manager::bind(const std::string& addr) {
  if (torrent::listen_port() != 0) {
    torrent::listen_close();
    torrent::set_bind_address(addr);
    listen_open();

  } else {
    torrent::set_bind_address(addr);
  }

  m_pollManager->get_http_stack()->set_bind_address(torrent::bind_address());
}

void
Manager::prepare_hash_check(Download* d) {
  m_downloadList.close(d);
  d->get_download().hash_resume_clear();
  m_downloadList.open(d);

  if (d->get_download().is_hash_checking() ||
      d->get_download().is_hash_checked())
    throw std::logic_error("Manager::check_hash(...) closed the torrent but is_hash_check{ing,ed}() == true");

  if (m_hashQueue.find(d) != m_hashQueue.end())
    throw std::logic_error("Manager::check_hash(...) closed the torrent but it was found in m_hashQueue");
}

void
Manager::receive_http_failed(std::string msg) {
  m_logImportant.push_front("Http download error: \"" + msg + "\"");
  m_logComplete.push_front("Http download error: \"" + msg + "\"");
}

void
Manager::receive_download_done_hash_checked(Download* d) {
  if (!d->get_download().is_active())
    m_downloadList.start(d);

  // Don't send if we did a hash check and found incompelete chunks.
  //if (d->is_done())
  d->get_download().tracker_send_completed();
}

void
Manager::try_create_download(const std::string& uri, bool start, bool printLog, bool tied) {
  // Adding download.
  DownloadFactory* f = new DownloadFactory(uri, this);

  f->variables()->set("tied_to_file", tied ? "yes" : "no");

  f->set_start(start);
  f->set_print_log(printLog);
  f->slot_finished(sigc::bind(sigc::ptr_fun(&rak::call_delete_func<core::DownloadFactory>), f));
  f->load();
  f->commit();
}

// Move this somewhere better.
void
path_expand(std::vector<std::string>* paths, const std::string& pattern) {
  std::vector<utils::Directory> currentCache;
  std::vector<utils::Directory> nextCache;

  rak::split_iterator_t<std::string> first = rak::split_iterator(pattern, '/');
  rak::split_iterator_t<std::string> last = rak::split_iterator(pattern);
    
  if (first == last)
    return;

  // Check for initial '/' that indicates the root.
  if ((*first).empty()) {
    currentCache.push_back(utils::Directory("/"));
    ++first;
  } else {
    currentCache.push_back(utils::Directory("./"));
  }

  // Might be an idea to use depth-first search instead.

  for (; first != last; ++first) {
    rak::regex r(*first);

    if (r.pattern().empty())
      continue;

    // Special case for ".."?

    for (std::vector<utils::Directory>::iterator itr = currentCache.begin(); itr != currentCache.end(); ++itr) {
      // Only include filenames starting with '.' if the pattern
      // starts with the same.
      itr->update(r.pattern()[0] != '.');
      itr->erase(std::remove_if(itr->begin(), itr->end(), std::not1(r)), itr->end());

      std::transform(itr->begin(), itr->end(), std::back_inserter(nextCache), std::bind1st(std::plus<std::string>(), itr->get_path() + "/"));
    }

    currentCache.clear();
    currentCache.swap(nextCache);
  }

  std::transform(currentCache.begin(), currentCache.end(), std::back_inserter(*paths), std::mem_fun_ref(&utils::Directory::get_path));
}

void
Manager::try_create_download_expand(const std::string& uri, bool start, bool printLog, bool tied) {
  std::vector<std::string> paths;
  paths.reserve(32);

  path_expand(&paths, uri);

  if (tied)
    for (std::vector<std::string>::iterator itr = paths.begin(); itr != paths.end(); )
      if (std::find_if(m_downloadList.begin(), m_downloadList.end(),
		       rak::equal(*itr, rak::bind2nd(std::mem_fun(&Download::variable_string), "tied_to_file"))) != m_downloadList.end())
	itr = paths.erase(itr);
      else
	itr++;

  if (!paths.empty())
    for (std::vector<std::string>::iterator itr = paths.begin(); itr != paths.end(); ++itr)
      try_create_download(*itr, start, printLog, tied);

  else
    try_create_download(uri, start, printLog, tied);
}

}