/*
 * UserCache.cpp
 *
 * Copyright (C) 2009 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "UserCache.h"
#include "Application.h"

namespace Mad {
namespace Common {

boost::shared_ptr<const std::map<unsigned long, UserInfo> > UserCache::getUserList(boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  boost::posix_time::ptime newTime(userTime);

  try {
    boost::shared_ptr<const std::map<unsigned long, UserInfo> > newUsers = backend->getUserList(&newTime);

    if(newUsers) {
      users = newUsers;
      userException = Core::Exception();
      userTime = newTime;

      userNames.reset(new std::map<Core::String, unsigned long>);
      for(std::map<unsigned long, UserInfo>::const_iterator user = users->begin(); user != users->end(); ++user)
        userNames->insert(std::make_pair(user->second.getUsername(), user->first));
    }
    else {
      if(users)
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Using cached user list");
      else
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Error cached");
    }
  }
  catch(Core::Exception e) {
    if(e.getErrorCode() != Core::Exception::NOT_AVAILABLE || !users) {
      users.reset();
      userException = e;
      userTime = newTime;
    }
  }

  if((!timestamp) || timestamp->is_not_a_date_time() || (*timestamp < userTime)) {
    if(timestamp)
      *timestamp = userTime;

    if(users)
      return users;
    else
      throw userException;
  }

  return boost::shared_ptr<const std::map<unsigned long, UserInfo> >();
}

boost::shared_ptr<const UserInfo> UserCache::getUserInfo(unsigned long uid, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getUserList(timestamp))
    return boost::shared_ptr<const UserInfo>();

  std::map<unsigned long, UserInfo>::const_iterator user = users->find(uid);

  if(user == users->end())
    throw Core::Exception(Core::Exception::NOT_FOUND);

  return boost::shared_ptr<UserInfo>(new UserInfo(user->second));
}

boost::shared_ptr<const UserInfo> UserCache::getUserInfoByName(const Core::String &name, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getUserList(timestamp))
    return boost::shared_ptr<const UserInfo>();

  std::map<Core::String, unsigned long>::const_iterator uid = userNames->find(name);
  if(uid == userNames->end())
    throw Core::Exception(Core::Exception::NOT_FOUND);

  std::map<unsigned long, UserInfo>::const_iterator user = users->find(uid->second);

  return boost::shared_ptr<UserInfo>(new UserInfo(user->second));
}

boost::shared_ptr<const std::set<unsigned long> > UserCache::getUserGroupList(unsigned long uid, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getFullUserGroupList(timestamp))
    return boost::shared_ptr<const std::set<unsigned long> >();

  std::pair<std::multimap<unsigned long, unsigned long>::const_iterator, std::multimap<unsigned long, unsigned long>::const_iterator> range = userGroups->equal_range(uid);

  boost::shared_ptr<std::set<unsigned long> > groups(new std::set<unsigned long>);

  for(std::multimap<unsigned long, unsigned long>::const_iterator group = range.first; group != range.second; ++group)
    groups->insert(group->second);

  return groups;
}


boost::shared_ptr<const std::map<unsigned long, GroupInfo> > UserCache::getGroupList(boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  boost::posix_time::ptime newTime(groupTime);

  try {
    boost::shared_ptr<const std::map<unsigned long, GroupInfo> > newGroups = backend->getGroupList(&newTime);

    if(newGroups) {
      groups = newGroups;
      groupException = Core::Exception();
      groupTime = newTime;

      groupNames.reset(new std::map<Core::String, unsigned long>);
      for(std::map<unsigned long, GroupInfo>::const_iterator group = groups->begin(); group != groups->end(); ++group)
        groupNames->insert(std::make_pair(group->second.getName(), group->first));
    }
    else {
      if(groups)
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Using cached group list");
      else
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Error cached");
    }
  }
  catch(Core::Exception e) {
    if(e.getErrorCode() != Core::Exception::NOT_AVAILABLE || !groups) {
      groups.reset();
      groupException = e;
      groupTime = newTime;
    }
  }

  if((!timestamp) || timestamp->is_not_a_date_time() || (*timestamp < groupTime)) {
    if(timestamp)
      *timestamp = groupTime;

    if(groups)
      return groups;
    else
      throw groupException;
  }

  return boost::shared_ptr<const std::map<unsigned long, GroupInfo> >();
}

boost::shared_ptr<const GroupInfo> UserCache::getGroupInfo(unsigned long gid, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getGroupList(timestamp))
    return boost::shared_ptr<const GroupInfo>();

  std::map<unsigned long, GroupInfo>::const_iterator group = groups->find(gid);

  if(group == groups->end())
    throw Core::Exception(Core::Exception::NOT_FOUND);

  return boost::shared_ptr<GroupInfo>(new GroupInfo(group->second));
}

boost::shared_ptr<const GroupInfo> UserCache::getGroupInfoByName(const Core::String &name, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getGroupList(timestamp))
    return boost::shared_ptr<const GroupInfo>();

  std::map<Core::String, unsigned long>::iterator gid = groupNames->find(name);
  if(gid == groupNames->end())
    throw Core::Exception(Core::Exception::NOT_FOUND);

  std::map<unsigned long, GroupInfo>::const_iterator group = groups->find(gid->second);

  return boost::shared_ptr<GroupInfo>(new GroupInfo(group->second));
}

boost::shared_ptr<const std::set<unsigned long> > UserCache::getGroupUserList(unsigned long gid, boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  if(!getFullUserGroupList(timestamp))
    return boost::shared_ptr<const std::set<unsigned long> >();

  std::pair<std::multimap<unsigned long, unsigned long>::iterator, std::multimap<unsigned long, unsigned long>::iterator> range = groupUsers->equal_range(gid);

  boost::shared_ptr<std::set<unsigned long> > users(new std::set<unsigned long>);

  for(std::multimap<unsigned long, unsigned long>::iterator user = range.first; user != range.second; ++user)
    users->insert(user->second);

  return users;
}

boost::shared_ptr<const std::multimap<unsigned long, unsigned long> > UserCache::getFullUserGroupList(boost::posix_time::ptime *timestamp) throw(Core::Exception) {
  boost::lock_guard<boost::recursive_mutex> lock(mutex);

  boost::posix_time::ptime newTime(userGroupTime);

  try {
    boost::shared_ptr<const std::multimap<unsigned long, unsigned long> > newUserGroups = backend->getFullUserGroupList(&newTime);

    if(newUserGroups) {
      userGroups = newUserGroups;
      userGroupException = Core::Exception();
      userGroupTime = newTime;

      groupUsers.reset(new std::multimap<unsigned long, unsigned long>);
      for(std::multimap<unsigned long, unsigned long>::const_iterator usergroup = userGroups->begin(); usergroup != userGroups->end(); ++usergroup)
        groupUsers->insert(std::make_pair(usergroup->second, usergroup->first));
    }
    else {
      if(userGroups)
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Using cached user-group table");
      else
        application->log(Core::Logger::LOG_USER, Core::Logger::LOG_DEBUG, "Error cached");
    }
  }
  catch(Core::Exception e) {
    if(e.getErrorCode() != Core::Exception::NOT_AVAILABLE || !userGroups) {
      userGroups.reset();
      userGroupException = e;
      userGroupTime = newTime;
    }
  }

  if((!timestamp) || timestamp->is_not_a_date_time() || (*timestamp < userTime)) {
    if(timestamp)
      *timestamp = userGroupTime;

    if(userGroups)
      return userGroups;
    else
      throw userGroupException;
  }

  return boost::shared_ptr<const std::multimap<unsigned long, unsigned long> >();
}

}
}