Code/net/minecraft/server/level/DemoMode.java

package net.minecraft.server.level;

import net.minecraft.core.BlockPos;
import net.minecraft.core.Direction;
import net.minecraft.network.chat.Component;
import net.minecraft.network.protocol.game.ClientboundGameEventPacket;
import net.minecraft.network.protocol.game.ServerboundPlayerActionPacket;
import net.minecraft.world.InteractionHand;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.level.Level;
import net.minecraft.world.phys.BlockHitResult;

public class DemoMode extends ServerPlayerGameMode {
    public static final int DEMO_DAYS = 5;
    public static final int TOTAL_PLAY_TICKS = 120500;
    private boolean displayedIntro;
    private boolean demoHasEnded;
    private int demoEndedReminder;
    private int gameModeTicks;

    public DemoMode(ServerPlayer p_143204_) {
        super(p_143204_);
    }

    @Override
    public void tick() {
        super.tick();
        this.gameModeTicks++;
        long i = this.level.getGameTime();
        long j = i / 24000L + 1L;
        if (!this.displayedIntro && this.gameModeTicks > 20) {
            this.displayedIntro = true;
            this.player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.DEMO_EVENT, 0.0F));
        }

        this.demoHasEnded = i > 120500L;
        if (this.demoHasEnded) {
            this.demoEndedReminder++;
        }

        if (i % 24000L == 500L) {
            if (j <= 6L) {
                if (j == 6L) {
                    this.player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.DEMO_EVENT, 104.0F));
                } else {
                    this.player.sendSystemMessage(Component.translatable("demo.day." + j));
                }
            }
        } else if (j == 1L) {
            if (i == 100L) {
                this.player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.DEMO_EVENT, 101.0F));
            } else if (i == 175L) {
                this.player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.DEMO_EVENT, 102.0F));
            } else if (i == 250L) {
                this.player.connection.send(new ClientboundGameEventPacket(ClientboundGameEventPacket.DEMO_EVENT, 103.0F));
            }
        } else if (j == 5L && i % 24000L == 22000L) {
            this.player.sendSystemMessage(Component.translatable("demo.day.warning"));
        }
    }

    private void outputDemoReminder() {
        if (this.demoEndedReminder > 100) {
            this.player.sendSystemMessage(Component.translatable("demo.reminder"));
            this.demoEndedReminder = 0;
        }
    }

    @Override
    public void handleBlockBreakAction(BlockPos p_214976_, ServerboundPlayerActionPacket.Action p_214977_, Direction p_214978_, int p_214979_, int p_214980_) {
        if (this.demoHasEnded) {
            this.outputDemoReminder();
        } else {
            super.handleBlockBreakAction(p_214976_, p_214977_, p_214978_, p_214979_, p_214980_);
        }
    }

    @Override
    public InteractionResult useItem(ServerPlayer p_140742_, Level p_140743_, ItemStack p_140744_, InteractionHand p_140745_) {
        if (this.demoHasEnded) {
            this.outputDemoReminder();
            return InteractionResult.PASS;
        } else {
            return super.useItem(p_140742_, p_140743_, p_140744_, p_140745_);
        }
    }

    @Override
    public InteractionResult useItemOn(ServerPlayer p_140747_, Level p_140748_, ItemStack p_140749_, InteractionHand p_140750_, BlockHitResult p_140751_) {
        if (this.demoHasEnded) {
            this.outputDemoReminder();
            return InteractionResult.PASS;
        } else {
            return super.useItemOn(p_140747_, p_140748_, p_140749_, p_140750_, p_140751_);
        }
    }
}