Merge pull request #92 from ThatCreeper/potion-api

Add a basic potion api

src/main/java/net/minestom/server/entity/Entity.java

@@ -22,6 +22,9 @@ import net.minestom.server.instance.block.CustomBlock;
 import net.minestom.server.network.packet.server.play.*;
 import net.minestom.server.permission.Permission;
 import net.minestom.server.permission.PermissionHandler;
+import net.minestom.server.potion.Potion;
+import net.minestom.server.potion.PotionEffect;
+import net.minestom.server.potion.TimedPotion;
 import net.minestom.server.thread.ThreadProvider;
 import net.minestom.server.utils.BlockPosition;
 import net.minestom.server.utils.Position;
@@ -41,6 +44,7 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
@@ -130,6 +134,8 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer, P
     protected boolean noGravity;
     protected Pose pose = Pose.STANDING;
 
+    private CopyOnWriteArrayList<TimedPotion> effects = new CopyOnWriteArrayList<>();
+
     // list of scheduled tasks to be executed during the next entity tick
     protected final Queue<Consumer<Entity>> nextTick = Queues.newConcurrentLinkedQueue();
 
@@ -396,6 +402,13 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer, P
             return;
         }
 
+        // remove expired effects
+        {
+            effects.removeIf(timedPotion -> time
+                    >=
+                    (timedPotion.getStartingTime() + timedPotion.getPotion().getDuration() * MinecraftServer.TICK_MS));
+        }
+
         // scheduled tasks
         if (!nextTick.isEmpty()) {
             Consumer<Entity> callback;
@@ -1442,6 +1455,36 @@ public abstract class Entity implements Viewable, EventHandler, DataContainer, P
         DYING
     }
 
+    public List<TimedPotion> getActiveEffects() {
+        return effects;
+    }
+
+    /**
+     * Removes effect from entity, if it has it.
+     *
+     * @param effect The effect to remove
+     */
+    public void removeEffect(@NotNull PotionEffect effect) {
+        effects.removeIf(timedPotion -> {
+            if (timedPotion.getPotion().getEffect() == effect) {
+                timedPotion.getPotion().sendRemovePacket(this);
+                return true;
+            }
+            return false;
+        });
+    }
+
+    /**
+     * Adds an effect to an entity.
+     *
+     * @param potion The potion to add
+     */
+    public void addEffect(@NotNull Potion potion) {
+        removeEffect(potion.getEffect());
+        effects.add(new TimedPotion(potion, System.currentTimeMillis()));
+        potion.sendAddPacket(this);
+    }
+
     protected boolean shouldRemove() {
         return shouldRemove;
     }

src/main/java/net/minestom/server/listener/PlayerDiggingListener.java

@@ -14,6 +14,7 @@ import net.minestom.server.network.packet.client.play.ClientPlayerDiggingPacket;
 import net.minestom.server.network.packet.server.play.AcknowledgePlayerDiggingPacket;
 import net.minestom.server.network.packet.server.play.EntityEffectPacket;
 import net.minestom.server.network.packet.server.play.RemoveEntityEffectPacket;
+import net.minestom.server.potion.Potion;
 import net.minestom.server.potion.PotionEffect;
 import net.minestom.server.utils.BlockPosition;
 
@@ -189,10 +190,14 @@ public class PlayerDiggingListener {
 
         EntityEffectPacket entityEffectPacket = new EntityEffectPacket();
         entityEffectPacket.entityId = player.getEntityId();
-        entityEffectPacket.effect = PotionEffect.MINING_FATIGUE;
-        entityEffectPacket.amplifier = -1;
-        entityEffectPacket.duration = 0;
-        entityEffectPacket.flags = 0;
+        entityEffectPacket.potion = new Potion(
+                PotionEffect.MINING_FATIGUE,
+                (byte) -1,
+                0,
+                false,
+                false,
+                false
+        );
         player.getPlayerConnection().sendPacket(entityEffectPacket);
     }
 

src/main/java/net/minestom/server/network/packet/server/play/EntityEffectPacket.java

@@ -2,25 +2,22 @@ package net.minestom.server.network.packet.server.play;
 
 import net.minestom.server.network.packet.server.ServerPacket;
 import net.minestom.server.network.packet.server.ServerPacketIdentifier;
-import net.minestom.server.potion.PotionEffect;
+import net.minestom.server.potion.Potion;
 import net.minestom.server.utils.binary.BinaryWriter;
 import org.jetbrains.annotations.NotNull;
 
 public class EntityEffectPacket implements ServerPacket {
 
     public int entityId;
-    public PotionEffect effect;
-    public byte amplifier;
-    public int duration;
-    public byte flags;
+    public Potion potion;
 
     @Override
     public void write(@NotNull BinaryWriter writer) {
         writer.writeVarInt(entityId);
-        writer.writeByte((byte) effect.getId());
-        writer.writeByte(amplifier);
-        writer.writeVarInt(duration);
-        writer.writeByte(flags);
+        writer.writeByte((byte) potion.getEffect().getId());
+        writer.writeByte(potion.getAmplifier());
+        writer.writeVarInt(potion.getDuration());
+        writer.writeByte(potion.getFlags());
     }
 
     @Override

src/main/java/net/minestom/server/potion/Potion.java

@@ -0,0 +1,118 @@
+package net.minestom.server.potion;
+
+import net.minestom.server.entity.Entity;
+import net.minestom.server.network.packet.server.play.EntityEffectPacket;
+import net.minestom.server.network.packet.server.play.RemoveEntityEffectPacket;
+import org.jetbrains.annotations.NotNull;
+
+public class Potion {
+    private final PotionEffect effect;
+    private final byte amplifier;
+    private final int duration;
+    private final byte flags;
+
+    /**
+     * Creates a new potion.
+     *
+     * @param effect The type of potion.
+     * @param amplifier The strength of the potion.
+     * @param duration The length of the potion in ticks.
+     */
+    public Potion(PotionEffect effect, byte amplifier, int duration) {
+        this(effect, amplifier, duration, true, true, false);
+    }
+
+    /**
+     * Creates a new potion.
+     *
+     * @param effect The type of potion.
+     * @param amplifier The strength of the potion.
+     * @param duration The length of the potion in ticks.
+     * @param particles If the potion has particles.
+     */
+    public Potion(PotionEffect effect, byte amplifier, int duration, boolean particles) {
+        this(effect, amplifier, duration, particles, true, false);
+    }
+
+    /**
+     * Creates a new potion.
+     *
+     * @param effect The type of potion.
+     * @param amplifier The strength of the potion.
+     * @param duration The length of the potion in ticks.
+     * @param particles If the potion has particles.
+     * @param icon If the potion has an icon.
+     */
+    public Potion(PotionEffect effect, byte amplifier, int duration, boolean particles, boolean icon) {
+        this(effect, amplifier, duration, particles, icon, false);
+    }
+
+    /**
+     * Creates a new potion.
+     *
+     * @param effect The type of potion.
+     * @param amplifier The strength of the potion.
+     * @param duration The length of the potion in ticks.
+     * @param particles If the potion has particles.
+     * @param icon If the potion has an icon.
+     * @param ambient If the potion came from a beacon.
+     */
+    public Potion(PotionEffect effect, byte amplifier, int duration, boolean particles, boolean icon, boolean ambient) {
+        this.effect = effect;
+        this.amplifier = amplifier;
+        this.duration = duration;
+        byte flags = 0;
+        if (ambient) {
+            flags = (byte) (flags | 0x01);
+        }
+        if (particles) {
+            flags = (byte) (flags | 0x02);
+        }
+        if (icon) {
+            flags = (byte) (flags | 0x04);
+        }
+        this.flags = flags;
+    }
+
+    public PotionEffect getEffect() {
+        return effect;
+    }
+
+    public byte getAmplifier() {
+        return amplifier;
+    }
+
+    public int getDuration() {
+        return duration;
+    }
+
+    public byte getFlags() {
+        return flags;
+    }
+
+    /**
+     * Sends a packet that a potion effect has been applied to the entity.
+     * <p>
+     * Used internally by {@link net.minestom.server.entity.Player#addEffect(Potion)}
+     * @param entity
+     */
+    public void sendAddPacket(@NotNull Entity entity) {
+        EntityEffectPacket eep = new EntityEffectPacket();
+        eep.entityId = entity.getEntityId();
+        eep.potion = this;
+        entity.sendPacketToViewersAndSelf(eep);
+    }
+
+    /**
+     * Sends a packet that a potion effect has been removed from the entity.
+     * <p>
+     * Used internally by {@link net.minestom.server.entity.Player#removeEffect(PotionEffect)}
+     * @param entity
+     */
+    public void sendRemovePacket(@NotNull Entity entity) {
+        RemoveEntityEffectPacket reep = new RemoveEntityEffectPacket();
+        reep.entityId = entity.getEntityId();
+        reep.effect = effect;
+        entity.sendPacketToViewersAndSelf(reep);
+    }
+}

src/main/java/net/minestom/server/potion/TimedPotion.java

@@ -0,0 +1,19 @@
+package net.minestom.server.potion;
+
+public class TimedPotion {
+    private final Potion potion;
+    private final long startingTime;
+
+    public TimedPotion(Potion potion, long startingTime) {
+        this.potion = potion;
+        this.startingTime = startingTime;
+    }
+
+    public Potion getPotion() {
+        return potion;
+    }
+
+    public long getStartingTime() {
+        return startingTime;
+    }
+}

src/test/java/demo/Main.java

@@ -39,6 +39,7 @@ public class Main {
         commandManager.register(new ShutdownCommand());
         commandManager.register(new TeleportCommand());
         commandManager.register(new PlayersCommand());
+        commandManager.register(new PotionCommand());
 
         commandManager.setUnknownCommandCallback((sender, command) -> sender.sendMessage("unknown command"));
 

src/test/java/demo/PlayerInit.java

@@ -29,6 +29,7 @@ import net.minestom.server.item.Material;
 import net.minestom.server.network.ConnectionManager;
 import net.minestom.server.network.packet.server.play.PlayerListHeaderAndFooterPacket;
 import net.minestom.server.ping.ResponseDataConsumer;
+import net.minestom.server.timer.TaskBuilder;
 import net.minestom.server.utils.PacketUtils;
 import net.minestom.server.utils.Position;
 import net.minestom.server.utils.Vector;

src/test/java/demo/commands/PotionCommand.java

@@ -0,0 +1,51 @@
+package demo.commands;
+
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.command.CommandSender;
+import net.minestom.server.command.builder.Arguments;
+import net.minestom.server.command.builder.Command;
+import net.minestom.server.command.builder.arguments.Argument;
+import net.minestom.server.command.builder.arguments.ArgumentType;
+import net.minestom.server.entity.Player;
+import net.minestom.server.potion.Potion;
+import net.minestom.server.potion.PotionEffect;
+
+public class PotionCommand extends Command {
+
+    public PotionCommand() {
+        super("potion");
+
+        setCondition(this::condition);
+
+        setDefaultExecutor(((sender, args) -> {
+            sender.sendMessage("Usage: /potion [type] [duration (seconds)]");
+        }));
+
+        Argument potionArg = ArgumentType.Potion("potion");
+        Argument durationArg = ArgumentType.Integer("duration");
+
+        addSyntax(this::onPotionCommand, potionArg, durationArg);
+    }
+
+    private boolean condition(CommandSender sender, String commandString) {
+        if (!sender.isPlayer()) {
+            sender.sendMessage("The command is only available for players");
+            return false;
+        }
+        return true;
+    }
+
+    private void onPotionCommand(CommandSender sender, Arguments args) {
+        final Player player = (Player) sender;
+        final PotionEffect potion = args.getPotionEffect("potion");
+        final int duration = args.getInteger("duration");
+
+        player.sendMessage(player.getActiveEffects().toString());
+        player.addEffect(new Potion(
+                potion,
+                (byte) 0,
+                duration * MinecraftServer.TICK_PER_SECOND
+        ));
+    }
+
+}