Server/src/engine/gameManager/SimulationManager.java

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//      Magicbane Emulator Project © 2013 - 2022
//                www.magicbane.com

package engine.gameManager;

import engine.Enum;
import engine.Enum.GameObjectType;
import engine.objects.AbstractGameObject;
import engine.objects.City;
import engine.objects.PlayerCharacter;
import engine.objects.Runegate;
import org.pmw.tinylog.Logger;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.Duration;
import java.time.Instant;
import java.util.Collection;

/*
 * This class contains all methods necessary to drive periodic
 * updates of the game simulation from the main _exec loop.
 */
public enum SimulationManager {

    SERVERHEARTBEAT;

    private static final long CITY_PULSE = 2000;
    private static final long RUNEGATE_PULSE = 3000;
    private static final long UPDATE_PULSE = 1000;
    private static final long FlIGHT_PULSE = 100;
    public static Duration executionTime = Duration.ofNanos(1);
    public static Duration executionMax = Duration.ofNanos(1);
    private static SimulationManager instance = null;
    private long _cityPulseTime = System.currentTimeMillis() + CITY_PULSE;
    private long _runegatePulseTime = System.currentTimeMillis()
            + RUNEGATE_PULSE;
    private long _updatePulseTime = System.currentTimeMillis() + UPDATE_PULSE;
    private long _flightPulseTime = System.currentTimeMillis() + FlIGHT_PULSE;

    private SimulationManager() {

        // don't allow instantiation.
    }

    public static String getPopulationString() {

        String popString = "";

        try (Connection connection = DbManager.getConnection();
             PreparedStatement getPopString = connection.prepareStatement("CALL GET_POPULATION_STRING()");) {

            ResultSet rs = getPopString.executeQuery();

            if (rs.next())
                popString = rs.getString("popstring");

        } catch (SQLException e) {
            Logger.error(e.toString());
        }

        return popString;
    }

    /*
     * Update the simulation. *** Important: Whatever you do in here, do it damn
     * quick!
     */
    public void tick() {

        /*
         * As we're on the main thread we must be sure to catch any possible
         * errors.
         *
         * IF something does occur, disable that particular heartbeat. Better
         * runegates stop working than the game itself!
         */

        Instant startTime = Instant.now();

        try {
            if ((_flightPulseTime != 0)
                    && (System.currentTimeMillis() > _flightPulseTime))
                pulseFlight();
        } catch (Exception e) {
            Logger.error(
                    "Fatal error in City Pulse: DISABLED. Error Message : "
                            + e.getMessage());
        }
        try {

            if ((_updatePulseTime != 0)
                    && (System.currentTimeMillis() > _updatePulseTime))
                pulseUpdate();
        } catch (Exception e) {
            Logger.error(
                    "Fatal error in Update Pulse: DISABLED");
            //  _runegatePulseTime = 0;
        }

        try {
            if ((_runegatePulseTime != 0)
                    && (System.currentTimeMillis() > _runegatePulseTime))
                pulseRunegates();
        } catch (Exception e) {
            Logger.error(
                    "Fatal error in Runegate Pulse: DISABLED");
            _runegatePulseTime = 0;
        }

        try {
            if ((_cityPulseTime != 0)
                    && (System.currentTimeMillis() > _cityPulseTime))
                pulseCities();
        } catch (Exception e) {
            Logger.error(
                    "Fatal error in City Pulse: DISABLED. Error Message : "
                            + e.getMessage());
            e.printStackTrace();

        }

        SimulationManager.executionTime = Duration.between(startTime, Instant.now());

        if (executionTime.compareTo(executionMax) > 0)
            executionMax = executionTime;
    }

    /*
     * Mainline simulation update method: handles movement and regen for all
     * player characters
     */

    private void pulseUpdate() {

        Collection<AbstractGameObject> playerList;

        playerList = DbManager.getList(GameObjectType.PlayerCharacter);

        // Call update() on each player in game

        if (playerList == null)
            return;

        for (AbstractGameObject ago : playerList) {
            PlayerCharacter player = (PlayerCharacter) ago;

            if (player == null)
                continue;
            player.update();
        }

        _updatePulseTime = System.currentTimeMillis() + 500;
    }

    private void pulseFlight() {

        Collection<AbstractGameObject> playerList;

        playerList = DbManager.getList(GameObjectType.PlayerCharacter);

        // Call update() on each player in game

        if (playerList == null)
            return;

        for (AbstractGameObject ago : playerList) {
            PlayerCharacter player = (PlayerCharacter) ago;

            if (player == null)
                continue;


            player.updateFlight();
        }

        _flightPulseTime = System.currentTimeMillis() + FlIGHT_PULSE;
    }

    private void pulseCities() {

        City city;

        // *** Refactor: Need a list cached somewhere as it doesn't change very
        // often at all.  Have a cityListIsDirty boolean that gets set if it
        // needs an update.  Will speed up this method a great deal.

        Collection<AbstractGameObject> cityList = DbManager.getList(Enum.GameObjectType.City);

        if (cityList == null) {
            Logger.info("City List null");
            return;
        }

        for (AbstractGameObject cityObject : cityList) {
            city = (City) cityObject;
            city.onEnter();
        }

        _cityPulseTime = System.currentTimeMillis() + CITY_PULSE;
    }

    /*
     * Method runs proximity collision detection for all active portals on the
     * game's Runegates
     */
    private void pulseRunegates() {

        for (Runegate runegate : Runegate._runegates.values()) {
            runegate.collidePortals();
        }

        _runegatePulseTime = System.currentTimeMillis() + RUNEGATE_PULSE;

    }
}