add push towards

Author: sovdeeth

src/main/java/ch/njol/skript/effects/EffPush.java

@@ -8,49 +8,75 @@
 import ch.njol.skript.lang.Effect;
 import ch.njol.skript.lang.Expression;
 import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.skript.lang.SyntaxStringBuilder;
 import ch.njol.skript.util.Direction;
 import ch.njol.util.Kleenean;
+import org.bukkit.Location;
 import org.bukkit.entity.Entity;
 import org.bukkit.event.Event;
 import org.bukkit.util.Vector;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.function.Function;
+
 @Name("Push")
-@Description("Push entities around.")
+@Description("Push entities in a given direction or towards a specific location.")
 @Example("push the player upwards")
 @Example("push the victim downwards at speed 0.5")
-@Example("push player along vector from player to player's target at speed 2")
-@Since("1.4.6")
+@Example("push player towards player's target at speed 2")
+@Since({"1.4.6", "INSERT VERSION (push towards)"})
 public class EffPush extends Effect {
 
 	static {
-		Skript.registerEffect(EffPush.class, "(push|thrust) %entities% [along] %direction% [(at|with) (speed|velocity|force) %-number%]");
+		Skript.registerEffect(EffPush.class,
+			"(push|thrust) %entities% [along] %direction% [(at|with) [a] (speed|velocity|force) [of] %-number%]",
+			"(push|thrust|pull) %entities% towards %location% [(at|with) [a] (speed|velocity|force) [of] %-number%]");
 	}
 
 	private Expression<Entity> entities;
-	private Expression<Direction> direction;
+	private @Nullable Expression<Direction> direction;
+	private @Nullable Expression<Location> target;
 	private @Nullable Expression<Number> speed = null;
 
 	@SuppressWarnings({"unchecked", "null"})
 	@Override
 	public boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
 		entities = (Expression<Entity>) exprs[0];
-		direction = (Expression<Direction>) exprs[1];
+		if (matchedPattern == 0) {
+			direction = (Expression<Direction>) exprs[1];
+		} else {
+			target = (Expression<Location>) exprs[1];
+		}
 		speed = (Expression<Number>) exprs[2];
 		return true;
 	}
 
 	@Override
 	protected void execute(Event event) {
-		Direction direction = this.direction.getSingle(event);
-		if (direction == null)
-			return;
 		Number speed = this.speed != null ? this.speed.getSingle(event) : null;
 		if (this.speed != null && speed == null)
 			return;
+
+		Function<Entity, Vector> getDirection;
+		if (this.direction != null) {
+			// push along
+			Direction direction = this.direction.getSingle(event);
+			if (direction == null)
+				return;
+			getDirection = direction::getDirection;
+		} else {
+			// push towards
+			assert this.target != null;
+			Location target = this.target.getSingle(event);
+			if (target == null)
+				return;
+			Vector targetVector = target.toVector();
+			getDirection = entity -> targetVector.subtract(entity.getLocation().toVector());
+		}
+
 		Entity[] entities = this.entities.getArray(event);
 		for (Entity entity : entities) {
-			Vector pushDirection = direction.getDirection(entity);
+			Vector pushDirection = getDirection.apply(entity);
 			if (speed != null)
 				pushDirection.normalize().multiply(speed.doubleValue());
 			if (!(Double.isFinite(pushDirection.getX()) && Double.isFinite(pushDirection.getY()) && Double.isFinite(pushDirection.getZ()))) {
@@ -60,11 +86,19 @@ protected void execute(Event event) {
 			entity.setVelocity(entity.getVelocity().add(pushDirection));
 		}
 	}
-	
+
 	@Override
 	public String toString(@Nullable Event event, boolean debug) {
-		return "push " + entities.toString(event, debug) + " " + direction.toString(event, debug) +
-				(speed != null ? " at speed " + speed.toString(event, debug) : "");
+		var ssb = new SyntaxStringBuilder(event, debug).append("push", entities);
+		if (direction != null) {
+			ssb.append(direction);
+		} else {
+			assert target != null;
+			ssb.append("towards", target);
+		}
+		if (speed != null)
+			ssb.append("at a speed of", speed);
+		return ssb.toString();
 	}
 
 }