/*****************************************************************************
 * Eliot
 * Copyright (C) 2005-2012 Olivier Teulière
 * Authors: Olivier Teulière <ipkiss @@ gmail.com>
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *****************************************************************************/

#include <boost/foreach.hpp>

#include <iomanip>
#include <wctype.h>

#include "freegame.h"
#include "game_exception.h"
#include "dic.h"
#include "tile.h"
#include "rack.h"
#include "round.h"
#include "move.h"
#include "pldrack.h"
#include "results.h"
#include "player.h"
#include "cmd/player_event_cmd.h"
#include "cmd/player_move_cmd.h"
#include "cmd/player_rack_cmd.h"
#include "cmd/game_move_cmd.h"
#include "cmd/game_rack_cmd.h"
#include "ai_player.h"
#include "settings.h"
#include "turn_data.h"
#include "encoding.h"

#include "debug.h"

INIT_LOGGER(game, FreeGame);


FreeGame::FreeGame(const GameParams &iParams, const Game *iMasterGame)
    : Game(iParams, iMasterGame), m_finished(false)
{
}


int FreeGame::play(const wstring &iCoord, const wstring &iWord)
{
    // Perform all the validity checks, and try to fill a round
    Move move;
    int res = checkPlayedWord(iCoord, iWord, move);
    if (res != 0 && Settings::Instance().getBool("freegame.reject-invalid"))
    {
        return res;
    }

    // If we reach this point, either the move is valid and we can use the
    // "move" variable, or it is invalid but played nevertheless
    recordPlayerMove(move, *m_players[m_currPlayer]);

    // Next turn
    endTurn();

    return 0;
}


void FreeGame::playAI(unsigned int p)
{
    ASSERT(p < getNPlayers(), "Wrong player number");
    ASSERT(!m_players[p]->isHuman(), "AI requested for a human player");

    AIPlayer *player = static_cast<AIPlayer*>(m_players[p]);

    player->compute(getDic(), getBoard(), getHistory().beforeFirstRound());
    const Move &move = player->getMove();
    if (move.isChangeLetters() || move.isPass())
    {
        ASSERT(checkPass(*player, move.getChangedLetters()) == 0,
               "AI tried to cheat!");
    }

    // Update the rack and the score of the current player
    recordPlayerMove(move, *player);

    endTurn();
}


void FreeGame::recordPlayerMove(const Move &iMove, Player &ioPlayer)
{
    LOG_INFO("Player " << ioPlayer.getId() << " plays: " << lfw(iMove.toString()));
    Command *pCmd = new PlayerMoveCmd(ioPlayer, iMove);
    accessNavigation().addAndExecute(pCmd);
}


void FreeGame::start()
{
    ASSERT(getNPlayers(), "Cannot start a game without any player");

    // Set the initial racks of the players
    BOOST_FOREACH(Player *player, m_players)
    {
        const PlayedRack &newRack =
            helperSetRackRandom(player->getCurrentRack(), false, RACK_NEW);
        Command *pCmd = new PlayerRackCmd(*player, newRack);
        accessNavigation().addAndExecute(pCmd);
    }

    // Set the game rack to the rack of the current player
    Command *pCmd = new GameRackCmd(*this, getPlayer(0).getCurrentRack());
    accessNavigation().addAndExecute(pCmd);

    // If the first player is an AI, make it play now
    if (!m_players[m_currPlayer]->isHuman())
    {
        playAI(m_currPlayer);
    }
}


bool FreeGame::isFinished() const
{
    // FIXME: the flag is never reset to false!
    return m_finished;
}


int FreeGame::endTurn()
{
    // Give a "no move" pseudo-move to all the players
    // who didn't play at this turn
    for (unsigned int i = 0; i < getNPlayers(); ++i)
    {
        if (i == m_currPlayer)
            continue;
        Command *pCmd = new PlayerMoveCmd(*m_players[i], Move());
        // The pseudo-moves should be completely transparent
        pCmd->setHumanIndependent(true);
        accessNavigation().addAndExecute(pCmd);
    }

    const Move &move = getCurrentPlayer().getLastMove();
    // Update the game
    Command *pCmd = new GameMoveCmd(*this, move);
    accessNavigation().addAndExecute(pCmd);

    // Complete the rack for the player that just played
    if (move.isValid() || move.isChangeLetters())
    {
        try
        {
            const PlayedRack &newRack =
                helperSetRackRandom(getCurrentPlayer().getCurrentRack(), false, RACK_NEW);
            Command *pCmd2 = new PlayerRackCmd(*m_players[m_currPlayer], newRack);
            accessNavigation().addAndExecute(pCmd2);
        }
        catch (EndGameException &e)
        {
            // End of the game
            endGame(m_currPlayer);
            return 1;
        }
    }

    if (allPlayersPassedThreeTimesInARow())
    {
        LOG_INFO("All the players passed 3 times consecutively");
        endGame(getNPlayers());
        return 2;
    }

    // Next player
    nextPlayer();

    // Set the game rack to the rack of the current player
    Command *pCmd3 = new GameRackCmd(*this, getCurrentPlayer().getCurrentRack());
    accessNavigation().addAndExecute(pCmd3);

    accessNavigation().newTurn();

    // If this player is an AI, make it play now
    if (!getCurrentPlayer().isHuman())
    {
        playAI(m_currPlayer);
    }

    return 0;
}


// Adjust the scores of the players with the points of the remaining tiles
void FreeGame::endGame(unsigned iWinningPlayer)
{
    LOG_INFO("End of the game");

    vector<Tile> tiles;

    // TODO: According to the rules of the game in the ODS, a game can end in 3
    // cases:
    // 1) no more letter in the bag, and one player has no letter in his rack
    // 2) the game is "blocked", no one can play
    // 3) the players have used all the time they had (for example: 30 min
    //    in total, for each player)
    // We currently handle case 1, and cannot handle case 3 until timers are
    // implemented.
    // For case 2, we need both to detect a blocked situation (not easy...) and
    // to handle it in the endGame() method (very easy). As a workaround for
    // case 2, we consider that if all players pass 3 times the game ends
    // without any winner.

    // Add the points of the remaining tiles to the score of the current
    // player (i.e. the first player with an empty rack), and remove them
    // from the score of the players who still have tiles
    int addedPoints = 0;
    for (unsigned int i = 0; i < getNPlayers(); i++)
    {
        if (i != iWinningPlayer)
        {
            const PlayedRack &pld = m_players[i]->getCurrentRack();
            pld.getAllTiles(tiles);
            int points = 0;
            BOOST_FOREACH(const Tile &tile, tiles)
            {
                points += tile.getPoints();
            }
            addedPoints += points;
            // Remove the points from the "losing" player
            Command *pCmd = new PlayerEventCmd(*m_players[i],
                                               PlayerEventCmd::END_GAME, -points);
            accessNavigation().addAndExecute(pCmd);
        }
    }
    // Give all the points to the winning player
    if (iWinningPlayer < getNPlayers())
    {
        Command *pCmd = new PlayerEventCmd(*m_players[m_currPlayer],
                                        PlayerEventCmd::END_GAME, addedPoints);
        accessNavigation().addAndExecute(pCmd);
    }

    // Lock game
    m_finished = true;
}


int FreeGame::checkPass(const Player &iPlayer,
                        const wstring &iToChange) const
{
    // Check that the game is not finished
    if (isFinished())
        return 3;

    // Check that the letters are valid for the current dictionary
    if (!getDic().validateLetters(iToChange))
        return 4;

    // It is forbidden to change letters when the bag does not contain at
    // least 7 letters (this is explicitly stated in the ODS). But it is
    // still allowed to pass
    Bag bag(getDic());
    realBag(bag);
    if (bag.getNbTiles() < 7 && !iToChange.empty())
    {
        return 1;
    }

    // Check that the letters are all present in the player's rack
    const PlayedRack &pld = iPlayer.getCurrentRack();
    Rack rack = pld.getRack();
    BOOST_FOREACH(wchar_t wch, iToChange)
    {
        // Remove the letter from the rack
        if (!rack.contains(Tile(wch)))
        {
            return 2;
        }
        rack.remove(Tile(wch));
    }

    // According to the rules in the ODS, it is allowed to pass its turn (no
    // need to change letters for that).
    // TODO: However, if all the players pass their turn, the first one has to
    // play, or change at least one letter. To implement this behaviour, we
    // must also take care of blocked positions, where no one _can_ play (see
    // also comment in the endGame() method).

    return 0;
}


int FreeGame::pass(const wstring &iToChange)
{
    Player &player = *m_players[m_currPlayer];
    int res = checkPass(player, iToChange);
    if (res != 0)
        return res;

    ASSERT(player.isHuman(), "AI tried to pass using the wrong method");

    Move move(iToChange);
    // End the player's turn
    recordPlayerMove(move, player);

    // Next game turn
    endTurn();

    return 0;
}


bool FreeGame::allPlayersPassedThreeTimesInARow() const
{
    const unsigned NB_OF_PASSES = 3;
    // Only one player really plays at each turn
    const unsigned NB_TURNS_TO_CHECK = NB_OF_PASSES * getNPlayers();

    bool result = true;
    BOOST_FOREACH(const Player *player, m_players)
    {
        const History &history = player->getHistory();
        result = result && (history.getSize() >= NB_TURNS_TO_CHECK);
        for (unsigned turnNb = history.getSize() - NB_TURNS_TO_CHECK;
             turnNb < history.getSize();
             ++turnNb)
        {
            const Move &move = history.getTurn(turnNb).getMove();
            // Players who did not play got a null move for the turn
            result = result && (move.isPass() || move.isNull());
        }
    }
    return result;
}