Move the unicorn shoot ability to the primary slot (second page) and add a separate ability specifically for cancelling spells

src/main/java/com/minelittlepony/unicopia/EquinePredicates.java

@@ -24,6 +24,7 @@ public interface EquinePredicates {
 
     Predicate<Entity> PLAYER_CAN_USE_EARTH = IS_PLAYER.and(raceMatches(Race::canUseEarth));
     Predicate<Entity> IS_CASTER = e -> !e.isRemoved() && (e instanceof Caster || PLAYER_UNICORN.test(e));
+    Predicate<Entity> IS_PLACED_SPELL = e -> e instanceof Caster && !e.isRemoved();
 
     Predicate<LivingEntity> HAS_WANT_IT_NEED_IT = e -> EnchantmentHelper.getEquipmentLevel(UEnchantments.WANT_IT_NEED_IT, e) > 0;
 

src/main/java/com/minelittlepony/unicopia/ability/Abilities.java

@@ -15,9 +15,10 @@ public interface Abilities {
 
     // unicorn / alicorn
     Ability<?> CAST = register(new UnicornCastingAbility(), "cast", AbilitySlot.PRIMARY);
+    Ability<?> SHOOT = register(new UnicornProjectileAbility(), "shoot", AbilitySlot.PRIMARY);
     Ability<?> TELEPORT = register(new UnicornTeleportAbility(), "teleport", AbilitySlot.SECONDARY);
     Ability<?> GROUP_TELEPORT = register(new UnicornGroupTeleportAbility(), "teleport_group", AbilitySlot.SECONDARY);
-    Ability<?> SHOOT = register(new UnicornProjectileAbility(), "shoot", AbilitySlot.TERTIARY);
+    Ability<?> DISPELL = register(new UnicornDispellAbility(), "dispell", AbilitySlot.TERTIARY);
 
     // earth / alicorn
     Ability<?> KICK = register(new EarthPonyKickAbility(), "kick", AbilitySlot.PRIMARY);

src/main/java/com/minelittlepony/unicopia/ability/UnicornCastingAbility.java

@@ -15,7 +15,6 @@ import com.minelittlepony.unicopia.particle.MagicParticleEffect;
 import com.minelittlepony.unicopia.util.RayTraceHelper;
 import com.minelittlepony.unicopia.util.VecHelper;
 
-import net.minecraft.entity.Entity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.particle.ParticleTypes;
 import net.minecraft.predicate.entity.EntityPredicates;

src/main/java/com/minelittlepony/unicopia/ability/UnicornDispellAbility.java

@@ -0,0 +1,91 @@
+package com.minelittlepony.unicopia.ability;
+
+import java.util.Optional;
+
+import com.minelittlepony.unicopia.EquinePredicates;
+import com.minelittlepony.unicopia.Race;
+import com.minelittlepony.unicopia.ability.data.Pos;
+import com.minelittlepony.unicopia.ability.magic.Caster;
+import com.minelittlepony.unicopia.entity.player.Pony;
+import com.minelittlepony.unicopia.particle.MagicParticleEffect;
+import com.minelittlepony.unicopia.util.RayTraceHelper;
+import com.minelittlepony.unicopia.util.VecHelper;
+
+/**
+ * Dispells an active spell
+ */
+public class UnicornDispellAbility implements Ability<Pos> {
+
+    @Override
+    public int getWarmupTime(Pony player) {
+        return 4;
+    }
+
+    @Override
+    public int getCooldownTime(Pony player) {
+        return 0;
+    }
+
+    @Override
+    public boolean canUse(Race race) {
+        return race.canCast();
+    }
+
+    @Override
+    public Pos.Serializer<Pos> getSerializer() {
+        return Pos.SERIALIZER;
+    }
+
+    @Override
+    public boolean onQuickAction(Pony player, ActivationType type) {
+
+        if (type.getTapCount() > 1) {
+            player.getSpellSlot().clear();
+            return true;
+        }
+        if (type == ActivationType.TAP) {
+            // TODO: gui to remove spells
+        }
+
+        return false;
+    }
+
+    @Override
+    public double getCostEstimate(Pony player) {
+        return getTarget(player)
+                .filter(caster -> caster.getMaster() != player.getMaster())
+                .isPresent() ? 10 : 0;
+    }
+
+    @Override
+    public Pos tryActivate(Pony player) {
+        return getTarget(player).map(Caster::getOrigin).map(Pos::new).orElse(null);
+    }
+
+    @Override
+    public void apply(Pony player, Pos data) {
+        Caster.stream(VecHelper.findInRange(player.getEntity(), player.getWorld(), data.vec(), 2, EquinePredicates.IS_PLACED_SPELL).stream()).forEach(target -> {
+            target.getSpellSlot().clear();
+        });
+    }
+
+    private Optional<Caster<?>> getTarget(Pony player) {
+        int maxDistance = player.getMaster().isCreative() ? 1000 : 100;
+        return RayTraceHelper.doTrace(player.getMaster(), maxDistance, 1,
+                EquinePredicates.IS_PLACED_SPELL)
+                .getEntity()
+            .flatMap(Caster::of);
+    }
+
+
+
+    @Override
+    public void preApply(Pony player, AbilitySlot slot) {
+        player.getMagicalReserves().getExhaustion().multiply(3.3F);
+        player.spawnParticles(MagicParticleEffect.UNICORN, 5);
+    }
+
+    @Override
+    public void postApply(Pony player, AbilitySlot slot) {
+    }
+}

src/main/java/com/minelittlepony/unicopia/ability/data/Numeric.java

@@ -1,13 +1,10 @@
 package com.minelittlepony.unicopia.ability.data;
 
-import com.google.gson.annotations.Expose;
-
 import net.minecraft.network.PacketByteBuf;
 
 public class Numeric extends Hit {
     public static final Serializer<Numeric> SERIALIZER = Numeric::new;
 
-    @Expose
     public int type;
 
     Numeric(PacketByteBuf buf) {

src/main/java/com/minelittlepony/unicopia/ability/data/Pos.java

@@ -4,6 +4,7 @@ import com.minelittlepony.unicopia.ability.magic.Caster;
 
 import net.minecraft.network.PacketByteBuf;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Vec3d;
 
 public class Pos extends Hit {
 
@@ -42,6 +43,10 @@ public class Pos extends Hit {
         return new BlockPos(x, y, z);
     }
 
+    public Vec3d vec() {
+        return new Vec3d(x, y, z);
+    }
+
     public double distanceTo(Caster<?> caster) {
         return Math.sqrt(caster.getEntity().squaredDistanceTo(x, y, z));
     }

src/main/java/com/minelittlepony/unicopia/ability/magic/Caster.java

@@ -93,10 +93,7 @@ public interface Caster<E extends LivingEntity> extends Owned<E>, Levelled, Affi
     }
 
     static Stream<Caster<?>> stream(Stream<Entity> entities) {
-        return entities
+        return entities.map(Caster::of).flatMap(Optional::stream);
-                .map(Caster::of)
-                .filter(Optional::isPresent)
-                .map(Optional::get);
     }
 
     /**

src/main/java/com/minelittlepony/unicopia/entity/CastSpellEntity.java

@@ -44,6 +44,13 @@ public class CastSpellEntity extends Entity implements Caster<LivingEntity>, Lig
             getDataTracker().set(SPELL, Optional.ofNullable(spell).map(Spell::getUuid));
             SpellContainer.Delegate.super.put(spell);
         }
+
+        @Override
+        public void clear() {
+            getDataTracker().get(SPELL).ifPresent(id -> {
+                delegate().removeIf(spell -> spell.getUuid().equals(id), true);
+            });
+        }
     };
 
     private final EntityReference<LivingEntity> owner = new EntityReference<>();
@@ -96,11 +103,11 @@ public class CastSpellEntity extends Entity implements Caster<LivingEntity>, Lig
 
         emitter.tick();
 
-        if (!dataTracker.get(SPELL).filter(spellId -> {
+        if (dataTracker.get(SPELL).filter(spellId -> {
             return getSpellSlot().forEach(spell -> {
                 return spell.getUuid().equals(spellId) ? Operation.ofBoolean(spell.tick(this, Situation.GROUND_ENTITY)) : Operation.SKIP;
             }, true);
-        }).isPresent()) {
+        }).isEmpty()) {
             discard();
         }
     }