Re-add backwards support down to 1.13

Also update PaperLib dependency and repo

pom.xml

@@ -40,7 +40,7 @@
         </repository>
         <repository>
             <id>paper-repo</id>
-            <url>https://papermc.io/repo/repository/maven-public/</url>
+            <url>https://repo.papermc.io/repository/maven-public/</url>
         </repository>
         <repository>
             <id>minebench-repo</id>
@@ -52,13 +52,13 @@
         <dependency>
             <groupId>org.spigotmc</groupId>
             <artifactId>spigot-api</artifactId>
-            <version>1.17.1-R0.1-SNAPSHOT</version>
+            <version>1.16.5-R0.1-SNAPSHOT</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
             <groupId>io.papermc</groupId>
             <artifactId>paperlib</artifactId>
-            <version>1.0.6</version>
+            <version>1.0.7</version>
             <scope>compile</scope>
         </dependency>
         <dependency>

randomteleport-plugin/src/main/java/de/themoep/randomteleport/RandomTeleport.java

@@ -83,6 +83,8 @@ public class RandomTeleport extends JavaPlugin implements RandomTeleportAPI {
     private Material[] unsafeBlocks;
     private Set<String> signVariables;
 
+    private boolean hasMinHeight = true;
+
     public void onEnable() {
         hookManager = new HookManager(this);
         loadConfig();
@@ -481,4 +483,21 @@ public class RandomTeleport extends JavaPlugin implements RandomTeleportAPI {
     public RandomSearcher getRandomSearcher(Player player, Location origin, int minRange, int maxRange, LocationValidator... validators) {
         return new RandomSearcher(this, player, origin, minRange, maxRange, validators);
     }
+
+    /**
+     * Utility method to get the min height of a world as old versions didn't have support for this.
+     * @param world The world
+     * @return The min height or 0 if querying that isn't supported
+     */
+    public int getMinHeight(World world) {
+        if (hasMinHeight) {
+            try {
+                return world.getMinHeight();
+            } catch (NoSuchMethodError ignored) {
+                // getMinHeight is only available starting in 1.16.5
+            }
+            hasMinHeight = false;
+        }
+        return 0;
+    }
 }

randomteleport-plugin/src/main/java/de/themoep/randomteleport/searcher/RandomSearcher.java

@@ -90,7 +90,7 @@ public class RandomSearcher {
         setCenter(center);
         setMinRadius(minRadius);
         setMaxRadius(maxRadius);
-        minY = center.getWorld().getMinHeight();
+        minY = plugin.getMinHeight(center.getWorld());
         if (center.getWorld().getEnvironment() == World.Environment.NETHER) {
             maxY = 126;
         } else {
@@ -257,7 +257,8 @@ public class RandomSearcher {
      * @param minY The min Y; has to be positive and less than the max Y!
      */
     public void setMinY(int minY) {
-        Validate.isTrue(minY >= center.getWorld().getMinHeight() && minY < maxY, "Min Y has to be at least the world's minimum height and less than the max Y!");
+        Validate.isTrue(minY >= plugin.getMinHeight(center.getWorld()), "Min Y has to be at least the world's minimum height!");
+        Validate.isTrue(minY < maxY, "Min Y has to be less than the max Y!");
         this.minY = minY;
     }
 
@@ -362,7 +363,7 @@ public class RandomSearcher {
         }
         lastCheck = center.getWorld().getTime();
         Location randomLoc = center.clone();
-        randomLoc.setY(center.getWorld().getMinHeight());
+        randomLoc.setY(plugin.getMinHeight(center.getWorld()));
         int minChunk = minRadius >> 4;
         int maxChunk = maxRadius >> 4;
         int randChunkX;

randomteleport-plugin/src/main/resources/plugin.yml

@@ -2,7 +2,7 @@ name: RandomTeleport
 provides: [FUBSRandomTeleport]
 main: de.themoep.randomteleport.RandomTeleport
 version: '${minecraft.plugin.version}'
-api-version: 1.17
+api-version: 1.13
 description: ${project.description}
 author: Phoenix616
 website: https://github.com/Phoenix616/RandomTeleport/