Expose the potential player cause of a lightning (#6782)

patches/api/More-lightning-API.patch

@@ -45,5 +45,39 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     * @param lifeTicks ticks the current flash will do damage for
 +     */
 +    void setLifeTicks(int lifeTicks);
++
++    /**
++     * Returns the potential entity that caused this lightning strike to spawn in the world.
++     * <p>
++     * As of implementing this method, only {@link Player}s are capable of causing a lightning strike, however as this
++     * might change in future minecraft releases, this method does not guarantee a player as the cause of a lightning.
++     * Consumers of this method should hence validate whether or not the entity is a player if they want to use player
++     * specific methods through an {@code instanceOf} check.
++     * </p>
++     * <p>
++     * A player is, as of implementing this method, responsible for a lightning, and will hence be returned here as
++     * a cause, if they channeled a {@link Trident} to summon it or were explicitly defined as the cause of this
++     * lightning through {@link #setCausingPlayer(Player)}.
++     * </p>
++     *
++     * @return the entity that caused this lightning or null if the lightning was not caused by a entity (e.g. normal
++     * weather)
++     */
++    @org.jetbrains.annotations.Nullable
++    Entity getCausingEntity();
++
++    /**
++     * Updates the player that caused this lightning to be summoned into the world.
++     * By default, players that channel their {@link Trident} will be the cause of the respective lightning.
++     * <p>
++     * While the respective getter method {@link #getCausingEntity()} does not guarantee a player as the cause of a
++     * lightning to stay as future proof as possible, as of implementing this method, players are the only entities
++     * that can cause a lightning strike and hence this setter is restricted to players.
++     * </p>
++     *
++     * @param causingPlayer the player that should be the new cause of this lightning. {@code null} may be passed to
++     *                      indicate that no player is responsible for this lightning.
++     */
++    void setCausingPlayer(@org.jetbrains.annotations.Nullable Player causingPlayer);
 +    // Paper end
  }

patches/server/More-lightning-API.patch

@@ -34,5 +34,16 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    public void setLifeTicks(int lifeTicks) {
 +        getHandle().life = lifeTicks;
 +    }
++
++    @Override
++    public @org.jetbrains.annotations.Nullable org.bukkit.entity.Entity getCausingEntity() {
++        final var cause = this.getHandle().getCause();
++        return cause == null ? null : cause.getBukkitEntity();
++    }
++
++    @Override
++    public void setCausingPlayer(@org.jetbrains.annotations.Nullable org.bukkit.entity.Player causingPlayer) {
++        this.getHandle().setCause(causingPlayer == null ? null : ((CraftPlayer) causingPlayer).getHandle());
++    }
 +    // Paper end
  }