/*
 * Copyright 2007-2008 Thomas Gallinari <tg8187@yahoo.fr>
 * Copyright 2007-2008 Pierre-Benoit Besse <besse@gmail.com>
 * Copyright 2007-2008 Alexandre Galinier <alex.galinier@hotmail.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, see <http://www.gnu.org/licenses/>.
 */

#include "game.h"
#include "kapmanparser.h"
#include "settings.h"

#include <KgDifficulty>
#include <QStandardPaths>

const int Game::FPS = 40;
int Game::s_bonusDuration;
int Game::s_preyStateDuration;
qreal Game::s_durationRatio;

Game::Game() :
    m_isCheater(false),
    m_lives(3),
    m_points(0),
    m_level(1),
    m_nbEatenGhosts(0),
    m_soundGameOver(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/gameover.ogg"))),
    m_soundGhost(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/ghost.ogg"))),
    m_soundGainLife(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/life.ogg"))),
    m_soundEnergizer(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/energizer.ogg"))),
    m_soundBonus(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/bonus.ogg"))),
    m_soundPill(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/pill.ogg"))),
    m_soundLevelUp(QStandardPaths::locate(QStandardPaths::GenericDataLocation, QStringLiteral("sounds/kapman/levelup.ogg")))
{
    // Initialize the sound state
    setSoundsEnabled(Settings::sounds());

    // Timers for medium difficulty
    s_bonusDuration = 7000;
    s_preyStateDuration = 10000;
    // Difference ratio between low/high and medium speed
    s_durationRatio = 1.0;

    // Tells the KgDifficulty singleton that the game is not running
    Kg::difficulty()->setGameRunning(false);

    // Create the Maze instance
    m_maze = new Maze();
    connect(m_maze, &Maze::allElementsEaten, this, &Game::nextLevel);
    // Create the parser that will parse the XML file in order to initialize the Maze instance
    // This also creates all the characters
    KapmanParser kapmanParser(this);
    // Set the XML file as input source for the parser
    QFile mazeXmlFile(QStandardPaths::locate(QStandardPaths::AppDataLocation, QStringLiteral("defaultmaze.xml")));
    mazeXmlFile.open(QIODevice::ReadOnly);
    kapmanParser.parse(&mazeXmlFile);

    connect(m_kapman, &Kapman::sWinPoints, this, &Game::winPoints);

    // Initialize the characters speed timers duration considering the difficulty level
    switch (Kg::difficultyLevel()) {
    case KgDifficultyLevel::Easy:
        // Ratio low/medium speed
        s_durationRatio = Character::MEDIUM_SPEED / Character::LOW_SPEED;
        break;
    case KgDifficultyLevel::Medium:
        s_durationRatio = 1;
        break;
    case KgDifficultyLevel::Hard:
        // Ratio high/medium speed
        s_durationRatio = Character::MEDIUM_SPEED / Character::HIGH_SPEED;
        break;
    default:
        break;
    }

    for (int i = 0; i < m_ghosts.size(); ++i) {
        connect(m_ghosts[i], &Ghost::lifeLost, this, &Game::kapmanDeath);
        connect(m_ghosts[i], &Ghost::ghostEaten, this, &Game::ghostDeath);
        // Initialize the ghosts speed and the ghost speed increase considering the characters speed
        m_ghosts[i]->initSpeedInc();
    }
    m_kapman->initSpeedInc();

    // Initialize Bonus timer from the difficulty level
    m_bonusTimer = new QTimer(this);
    m_bonusTimer->setInterval((int)(s_bonusDuration * s_durationRatio));
    m_bonusTimer->setSingleShot(true);
    connect(m_bonusTimer, &QTimer::timeout, this, &Game::hideBonus);
    // Initialize the Preys timer from the difficulty level
    m_preyTimer = new QTimer(this);
    m_preyTimer->setInterval((int)(s_preyStateDuration * s_durationRatio));
    m_preyTimer->setSingleShot(true);
    connect(m_preyTimer, &QTimer::timeout, this, &Game::endPreyState);

    // Start the Game timer
    m_timer = new QTimer(this);
    m_timer->setInterval(int(1000 / Game::FPS));
    connect(m_timer, &QTimer::timeout, this, &Game::update);
    m_timer->start();
    m_state = RUNNING;
    // Init the characters coordinates on the Maze
    initCharactersPosition();
}

Game::~Game()
{
    delete m_timer;
    delete m_bonusTimer;
    delete m_maze;
    delete m_kapman;
    for (int i = 0; i < m_ghosts.size(); ++i) {
        delete m_ghosts[i];
    }
    delete m_bonus;
}

void Game::start()
{
    // Restart the Game timer
    m_timer->start();
    m_state = RUNNING;
    Q_EMIT pauseChanged(false, false);
}

void Game::pause(bool p_locked)
{
    // Stop the Game timer
    m_timer->stop();
    if (p_locked) {
        m_state = PAUSED_LOCKED;
    } else {
        m_state = PAUSED_UNLOCKED;
    }
    Q_EMIT pauseChanged(true, false);
}

void Game::switchPause(bool p_locked)
{
    // If the Game is not already paused
    if (m_state == RUNNING) {
        // Pause the Game
        pause(p_locked);
        Q_EMIT pauseChanged(true, true);
    }
    // If the Game is already paused
    else {
        // Resume the Game
        start();
        Q_EMIT pauseChanged(false, true);
    }
}

Kapman *Game::getKapman() const
{
    return m_kapman;
}

QList<Ghost *> Game::getGhosts() const
{
    return m_ghosts;
}

QTimer *Game::getTimer() const
{
    return m_timer;
}

Maze *Game::getMaze() const
{
    return m_maze;
}

bool Game::isPaused() const
{
    return (m_state != RUNNING);
}

bool Game::isCheater() const
{
    return m_isCheater;
}

int Game::getScore() const
{
    return m_points;
}
int Game::getLives() const
{
    return m_lives;
}

int Game::getLevel() const
{
    return m_level;
}

void Game::setLevel(int p_level)
{
    m_isCheater = true;
    m_level = p_level;
    m_maze->resetNbElem();
    m_timer->start();   // Needed to reinit character positions
    initCharactersPosition();
    for (int i = 0; i < m_ghosts.size(); ++i) {
        m_ghosts[i]->initSpeed();
    }
    m_kapman->initSpeed();
    for (int i = 0; i < m_level; ++i) {
        for (int j = 0; j < m_ghosts.size(); ++j) {
            m_ghosts[j]->increaseCharactersSpeed();
        }
        m_kapman->increaseCharactersSpeed();
    }
    setTimersDuration();
    m_bonus->setPoints(m_level * 100);
    Q_EMIT scoreChanged(m_points);
    Q_EMIT livesChanged(m_lives);
    Q_EMIT levelChanged(m_level);
    Q_EMIT pauseChanged(false, true);
    Q_EMIT levelStarted(true);
}

Bonus *Game::getBonus() const
{
    return m_bonus;
}

void Game::createBonus(QPointF p_position)
{
    m_bonus = new Bonus(qreal(Cell::SIZE * p_position.x()), qreal(Cell::SIZE * p_position.y()), m_maze, 100);
}

void Game::createKapman(QPointF p_position)
{
    m_kapman = new Kapman(qreal(Cell::SIZE * p_position.x()), qreal(Cell::SIZE * p_position.y()), m_maze);
}

void Game::createGhost(QPointF p_position, const QString &p_imageId)
{
    m_ghosts.append(new Ghost(qreal(Cell::SIZE * p_position.x()), qreal(Cell::SIZE * p_position.y()), p_imageId, m_maze));
}

void Game::initMaze(const int p_nbRows, const int p_nbColumns)
{
    m_maze->init(p_nbRows, p_nbColumns);
}

void Game::setSoundsEnabled(bool p_enabled)
{
    m_soundEnabled = p_enabled;
    Settings::setSounds(p_enabled);
    Settings::self()->save();
}

void Game::initCharactersPosition()
{
    // If the timer is stopped, it means that collisions are already being handled
    if (m_timer->isActive()) {
        // At the beginning, the timer is stopped but the Game isn't paused (to allow keyPressedEvent detection)
        m_timer->stop();
        m_state = RUNNING;
        // Initialize Ghost coordinates and state
        m_ghosts[0]->initCoordinate();
        m_ghosts[1]->initCoordinate();
        m_ghosts[2]->initCoordinate();
        m_ghosts[3]->initCoordinate();
        m_kapman->initCoordinate();
        m_ghosts[0]->setState(Ghost::HUNTER);
        m_ghosts[1]->setState(Ghost::HUNTER);
        m_ghosts[2]->setState(Ghost::HUNTER);
        m_ghosts[3]->setState(Ghost::HUNTER);
        m_kapman->init();
        // Initialize the Pills & Energizers coordinates
        for (int i = 0; i < m_maze->getNbRows(); ++i) {
            for (int j = 0; j < m_maze->getNbColumns(); ++j) {
                if (m_maze->getCell(i, j).getElement() != nullptr) {
                    m_maze->getCell(i, j).getElement()->setX(Cell::SIZE * (j + 0.5));
                    m_maze->getCell(i, j).getElement()->setY(Cell::SIZE * (i + 0.5));
                }
            }
        }
    }
}

void Game::setTimersDuration()
{
    // Updates the timers duration ratio with the ghosts speed
    s_durationRatio = Character::MEDIUM_SPEED / m_ghosts[0]->getNormalSpeed();

    // Updates the timers duration
    m_bonusTimer->setInterval((int)(s_bonusDuration * s_durationRatio));
    m_preyTimer->setInterval((int)(s_preyStateDuration * s_durationRatio));
}

void Game::keyPressEvent(QKeyEvent *p_event)
{
    // At the beginning or when paused, we start the timer when an arrow key is pressed
    if ((p_event->key() == Qt::Key_Up || p_event->key() == Qt::Key_Down || p_event->key() ==  Qt::Key_Left || p_event->key() == Qt::Key_Right) && !m_timer->isActive()) {
        // If paused
        if (m_state == PAUSED_UNLOCKED) {
            switchPause();
        } else if (m_state == RUNNING) {    // At the game beginning
            // Start the game
            m_timer->start();
            Q_EMIT gameStarted();
        }
        // Tells the KgDifficulty singleton that the game now runs
        Kg::difficulty()->setGameRunning(true);
    }
    // Behaviour when the game has begun
    switch (p_event->key()) {
    case Qt::Key_Up:
        if (m_state == RUNNING) {
            m_kapman->goUp();
        }
        break;
    case Qt::Key_Down:
        if (m_state == RUNNING) {
            m_kapman->goDown();
        }
        break;
    case Qt::Key_Right:
        if (m_state == RUNNING) {
            m_kapman->goRight();
        }
        break;
    case Qt::Key_Left:
        if (m_state == RUNNING) {
            m_kapman->goLeft();
        }
        break;
    case Qt::Key_P:
    case Qt::Key_Escape:
        switchPause();
        break;
    case Qt::Key_K:
        // Cheat code to get one more life
        if (p_event->modifiers() == (Qt::AltModifier | Qt::ControlModifier | Qt::ShiftModifier)) {
            m_lives++;
            m_isCheater = true;
            Q_EMIT livesChanged(m_lives);
        }
        break;
    case Qt::Key_L:
        // Cheat code to go to the next level
        if (p_event->modifiers() == (Qt::AltModifier | Qt::ControlModifier | Qt::ShiftModifier)) {
            m_isCheater = true;
            nextLevel();
        }
        break;
    default:
        break;
    }
}

void Game::update()
{
    int curKapmanRow, curKapmanCol;

    // Check if the kapman is in the line of sight of a ghost
    curKapmanRow = m_maze->getRowFromY(m_kapman->getY());
    curKapmanCol = m_maze->getColFromX(m_kapman->getX());

    for (int i = 0; i < m_ghosts.size(); ++i) {
        if (m_ghosts[i]->getState() == Ghost::HUNTER && m_ghosts[i]->isInLineSight(m_kapman)) {
            m_ghosts[i]->updateMove(curKapmanRow, curKapmanCol);
        } else {
            m_ghosts[i]->updateMove();
        }
    }
    m_kapman->updateMove();
    m_kapman->emitGameUpdated();
}

void Game::kapmanDeath()
{
    if (m_soundEnabled) {
        m_soundGameOver.start();
    }

    m_lives--;
    m_kapman->die();
    // Make a 2 seconds pause while the kapman is blinking
    pause(true);
    QTimer::singleShot(2500, this, &Game::resumeAfterKapmanDeath);
}

void Game::resumeAfterKapmanDeath()
{
    Q_EMIT livesChanged(m_lives);
    // Start the timer
    start();
    // Remove a possible bonus
    Q_EMIT bonusOff();
    // If their is no lives left, we start a new game
    if (m_lives <= 0) {
        Q_EMIT gameOver(true);
    } else {
        Q_EMIT levelStarted(false);
        // Move all characters to their initial positions
        initCharactersPosition();
    }
}

void Game::ghostDeath(Ghost *p_ghost)
{
    m_nbEatenGhosts++;
    p_ghost->setState(Ghost::EATEN);
    winPoints(p_ghost);
}

void Game::winPoints(Element *p_element)
{

    // The value of won Points
    long wonPoints;

    // If the eaten element is a ghost, win 200 * number of eaten ghosts since the energizer was eaten
    if (p_element->getType() == Element::GHOST) {
        if (m_soundEnabled) {
            m_soundGhost.start();
        }

        // Get the position of the ghost
        qreal xPos = p_element->getX();
        qreal yPos = p_element->getY();
        // Add points to the score
        wonPoints = p_element->getPoints() * m_nbEatenGhosts;
        // Send to the scene the number of points to display and its position
        Q_EMIT pointsToDisplay(wonPoints, xPos, yPos);
    }
    // Else you just win the value of the element
    else {
        wonPoints = p_element->getPoints();
    }

    // Update of the points value
    m_points += wonPoints;

    // For each 10000 points we get a life more
    if (m_points / 10000 > (m_points - wonPoints) / 10000) {
        if (m_soundEnabled) {
            m_soundGainLife.start();
        }

        m_lives++;
        Q_EMIT livesChanged(m_lives);
    }
    // If the eaten element is an energyzer we change the ghosts state
    if (p_element->getType() == Element::ENERGYZER) {
        // We start the prey timer
        m_preyTimer->start();

        if (m_soundEnabled) {
            m_soundEnergizer.start();
        }

        for (int i = 0; i < m_ghosts.size(); ++i) {
            if (m_ghosts[i]->getState() != Ghost::EATEN) {
                m_ghosts[i]->setState(Ghost::PREY);
            }
        }
        // Reset the number of eaten ghosts
        m_nbEatenGhosts = 0;
        Q_EMIT elementEaten(p_element->getX(), p_element->getY());
    } else if (p_element->getType() == Element::PILL) {
        if (m_soundEnabled) {
            m_soundPill.start();
        }

        Q_EMIT elementEaten(p_element->getX(), p_element->getY());
    } else if (p_element->getType() == Element::BONUS) {
        if (m_soundEnabled) {
            m_soundBonus.start();
        }

        // Get the position of the Bonus
        qreal xPos = p_element->getX();
        qreal yPos = p_element->getY();

        // Sends to the scene the number of points to display and its position
        Q_EMIT pointsToDisplay(wonPoints, xPos, yPos);

        Q_EMIT bonusOff();
    }
    // If 1/3 or 2/3 of the pills are eaten
    if (m_maze->getNbElem() == m_maze->getTotalNbElem() / 3 || m_maze->getNbElem() == (m_maze->getTotalNbElem() * 2 / 3)) {
        // Display the Bonus
        Q_EMIT bonusOn();
        m_bonusTimer->start();
    }
    Q_EMIT scoreChanged(m_points);
}

void Game::nextLevel()
{
    if (m_soundEnabled) {
        m_soundLevelUp.start();
    }

    // Increment the level
    m_level++;
    // Initialize the maze items
    m_maze->resetNbElem();
    // Update Bonus
    m_bonus->setPoints(m_level * 100);
    // Move all characters to their initial positions
    initCharactersPosition();
    // Increase the ghosts speed
    for (int i = 0; i < m_ghosts.size(); ++i) {
        // Increase the ghosts speed increase
        m_ghosts[i]->increaseCharactersSpeed();
    }
    m_kapman->increaseCharactersSpeed();
    // Update the timers duration with the new speed
    setTimersDuration();
    // Update the score, level and lives labels
    Q_EMIT scoreChanged(m_points);
    Q_EMIT livesChanged(m_lives);
    Q_EMIT levelChanged(m_level);
    // Update the view
    Q_EMIT levelStarted(true);
}

void Game::hideBonus()
{
    Q_EMIT bonusOff();
}

void Game::endPreyState()
{
    for (int i = 0; i < m_ghosts.size(); ++i) {
        if (m_ghosts[i]->getState() != Ghost::EATEN) {
            m_ghosts[i]->setState(Ghost::HUNTER);
        }
    }
}