add environment expression (#5070)

* add environment expression

src/main/java/ch/njol/skript/classes/data/BukkitClasses.java

@@ -39,6 +39,7 @@
 import org.bukkit.OfflinePlayer;
 import org.bukkit.SoundCategory;
 import org.bukkit.World;
+import org.bukkit.World.Environment;
 import org.bukkit.attribute.Attribute;
 import org.bukkit.block.Biome;
 import org.bukkit.block.Block;
@@ -1817,5 +1818,31 @@ public String toVariableNameString(Attribute a) {
 					}
 				})
 				.serializer(new EnumSerializer<>(Attribute.class)));
+
+		EnumUtils<Environment> environments = new EnumUtils<>(Environment.class, "environments");
+		Classes.registerClass(new ClassInfo<>(Environment.class, "environment")
+				.user("(world ?)?environments?")
+				.name("World Environment")
+				.description("Represents the environment of a world.")
+				.usage(environments.getAllNames())
+				.since("INSERT VERSION")
+				.parser(new Parser<Environment>() {
+					@Override
+					@Nullable
+					public Environment parse(String input, ParseContext context) {
+						return environments.parse(input);
+					}
+
+					@Override
+					public String toString(Environment environment, int flags) {
+						return environments.toString(environment, flags);
+					}
+
+					@Override
+					public String toVariableNameString(Environment environment) {
+						return toString(environment, 0);
+					}
+				})
+				.serializer(new EnumSerializer<>(Environment.class)));
 	}
 }

src/main/java/ch/njol/skript/expressions/ExprWorldEnvironment.java

@@ -0,0 +1,59 @@
+/**
+ *   This file is part of Skript.
+ *
+ *  Skript is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Skript is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Skript.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright Peter Güttinger, SkriptLang team and contributors
+ */
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Examples;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.expressions.base.SimplePropertyExpression;
+import org.bukkit.World;
+import org.bukkit.World.Environment;
+import org.eclipse.jdt.annotation.Nullable;
+
+@Name("World Environment")
+@Description("The environment of a world")
+@Examples({
+	"if environment of player's world is nether:",
+	"\tapply fire resistance to player for 10 minutes"
+})
+@Since("INSERT VERSION")
+public class ExprWorldEnvironment extends SimplePropertyExpression<World, Environment> {
+
+	static {
+		register(ExprWorldEnvironment.class, Environment.class, "[world] environment", "worlds");
+	}
+
+	@Override
+	@Nullable
+	public Environment convert(World world) {
+		return world.getEnvironment();
+	}
+
+	@Override
+	public Class<? extends Environment> getReturnType() {
+		return Environment.class;
+	}
+
+	@Override
+	protected String getPropertyName() {
+		return "environment";
+	}
+
+}

src/main/resources/lang/default.lang

@@ -1856,6 +1856,13 @@ attribute types:
 	horse_jump_strength: horse jump strength
 	zombie_spawn_reinforcements: zombie spawn reinforcements
 
+# -- Environments --
+environments:
+	normal: normal, overworld, the overworld
+	nether: nether, the nether
+	the_end: end, the end
+	custom: custom
+
 # -- Boolean --
 boolean:
 	true:

src/test/skript/tests/syntaxes/expressions/ExprWorldEnvironment.sk

@@ -0,0 +1,5 @@
+test "world environment":
+	assert environment of world "world" is normal with "main overworld was not environment ""normal"""
+	assert environment of world "world_the_end" is the end with "world_the_end was not environment ""the end"""
+	set {_environment} to environment of world "world"
+	assert {_environment} is overworld with "environment of world didn't compare with a variable"