SPIGOT-1638 / SPIGOT-1673: Rework Potions API

By: t00thpick1 <t00thpick1dirko@gmail.com>

paper-api/src/main/java/org/bukkit/entity/TippedArrow.java

@@ -1,3 +1,78 @@
 package org.bukkit.entity;
 
-public interface TippedArrow extends Arrow {}
+import java.util.List;
+
+import org.bukkit.potion.PotionData;
+import org.bukkit.potion.PotionEffect;
+import org.bukkit.potion.PotionEffectType;
+
+public interface TippedArrow extends Arrow {
+
+    /**
+     * Sets the underlying potion data
+     *
+     * @param data PotionData to set the base potion state to
+     */
+    void setBasePotionData(PotionData data);
+
+    /**
+     * Returns the potion data about the base potion
+     *
+     * @return a PotionData object
+     */
+    PotionData getBasePotionData();
+
+    /**
+     * Checks for the presence of custom potion effects.
+     *
+     * @return true if custom potion effects are applied
+     */
+    boolean hasCustomEffects();
+
+    /**
+     * Gets an immutable list containing all custom potion effects applied to
+     * this arrow.
+     * <p>
+     * Plugins should check that hasCustomEffects() returns true before calling
+     * this method.
+     *
+     * @return the immutable list of custom potion effects
+     */
+    List<PotionEffect> getCustomEffects();
+
+    /**
+     * Adds a custom potion effect to this arrow.
+     *
+     * @param effect the potion effect to add
+     * @param overwrite true if any existing effect of the same type should be
+     * overwritten
+     * @return true if the effect was added as a result of this call
+     */
+    boolean addCustomEffect(PotionEffect effect, boolean overwrite);
+
+    /**
+     * Removes a custom potion effect from this arrow.
+     *
+     * @param type the potion effect type to remove
+     * @return true if the an effect was removed as a result of this call
+     * @throws IllegalArgumentException if this operation would leave the Arrow
+     * in a state with no Custom Effects and PotionType.UNCRAFTABLE
+     */
+    boolean removeCustomEffect(PotionEffectType type);
+
+    /**
+     * Checks for a specific custom potion effect type on this arrow.
+     *
+     * @param type the potion effect type to check for
+     * @return true if the potion has this effect
+     */
+    boolean hasCustomEffect(PotionEffectType type);
+
+    /**
+     * Removes all custom potion effects from this arrow.
+     *
+     * @throws IllegalArgumentException if this operation would leave the Arrow
+     * in a state with no Custom Effects and PotionType.UNCRAFTABLE
+     */
+    void clearCustomEffects();
+}