/*
 * UserListDiff.h
 *
 * 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/>.
 */

#ifndef MAD_COMMON_USERLISTS_USERLISTDIFF_H_
#define MAD_COMMON_USERLISTS_USERLISTDIFF_H_

#include "../export.h"

#include "UserListEntry.h"
#include <Core/Exception.h>

#include <boost/bimap.hpp>
#include <set>

namespace Mad {
namespace Common {
namespace UserLists {

class UserList;

class MAD_COMMON_EXPORT UserListDiff {
  public:
    typedef boost::bimap<boost::bimaps::set_of<UserListEntry>, boost::bimaps::set_of<UserListEntry> > EntryListMap;

  private:
    std::set<UserListEntry> addedUsers;
    std::set<UserListEntry> deletedUsers;
    EntryListMap updatedUsers;

  public:
    UserListDiff() {}

    void invert() {
      addedUsers.swap(deletedUsers);
    }

    const std::set<UserListEntry>& getAddedUsers() const {
      return addedUsers;
    }

    const std::set<UserListEntry>& getDeletedUsers() const {
      return deletedUsers;
    }

    const EntryListMap& getUpdatedUsers() const {
      return updatedUsers;
    }

    bool insertAddedUser(UserListEntry user) {
      if(updatedUsers.right.count(user))
        return false;

      return addedUsers.insert(user).second;
    }

    bool insertDeletedUser(UserListEntry user) {
      if(updatedUsers.left.count(user))
        return false;

      return deletedUsers.insert(user).second;
    }

    bool insertUpdatedUser(UserListEntry oldUser, UserListEntry newUser) {
      if(deletedUsers.count(oldUser) || addedUsers.count(newUser))
        return false;

      // this won't allow exchanging two users, but that's ok for now...
      if(updatedUsers.left.count(oldUser) || updatedUsers.right.count(newUser))
        return false;
      if(updatedUsers.right.count(oldUser) || updatedUsers.left.count(newUser))
        return false;

      return updatedUsers.left.insert(std::make_pair(oldUser, newUser)).second;
    }
};

}
}
}

#endif /* MAD_COMMON_USERLISTS_USERLISTDIFF_H_ */