Refactor world info provider; only clamp to logical height when already below

Fixes #4657.

Essentials/src/main/java/com/earth2me/essentials/Essentials.java

@@ -47,6 +47,7 @@ import net.ess3.api.IEssentials;
 import net.ess3.api.IItemDb;
 import net.ess3.api.IJails;
 import net.ess3.api.ISettings;
+import net.ess3.nms.refl.providers.ReflDataWorldInfoProvider;
 import net.ess3.nms.refl.providers.ReflFormattedCommandAliasProvider;
 import net.ess3.nms.refl.providers.ReflKnownCommandsProvider;
 import net.ess3.nms.refl.providers.ReflOnlineModeProvider;
@@ -81,7 +82,7 @@ import net.ess3.provider.providers.LegacyPotionMetaProvider;
 import net.ess3.provider.providers.LegacySpawnEggProvider;
 import net.ess3.provider.providers.ModernItemUnbreakableProvider;
 import net.ess3.provider.providers.ModernPersistentDataProvider;
-import net.ess3.provider.providers.ModernWorldInfoProvider;
+import net.ess3.provider.providers.ModernDataWorldInfoProvider;
 import net.ess3.provider.providers.PaperContainerProvider;
 import net.ess3.provider.providers.PaperKnownCommandsProvider;
 import net.ess3.provider.providers.PaperMaterialTagProvider;
@@ -424,7 +425,9 @@ public class Essentials extends JavaPlugin implements net.ess3.api.IEssentials {
             }
 
             if (VersionUtil.getServerBukkitVersion().isHigherThanOrEqualTo(VersionUtil.v1_17_1_R01)) {
-                worldInfoProvider = new ModernWorldInfoProvider();
+                worldInfoProvider = new ModernDataWorldInfoProvider();
+            } else if (VersionUtil.getServerBukkitVersion().isHigherThanOrEqualTo(VersionUtil.v1_16_5_R01)) {
+                worldInfoProvider = new ReflDataWorldInfoProvider();
             } else {
                 worldInfoProvider = new FixedHeightWorldInfoProvider();
             }

Essentials/src/main/java/com/earth2me/essentials/RandomTeleport.java

@@ -177,7 +177,7 @@ public class RandomTeleport implements IConf {
         final Location location = new Location(
             center.getWorld(),
             center.getX() + offsetX,
-            ess.getWorldInfoProvider().getMaxSafeHeight(center.getWorld()),
+            ess.getWorldInfoProvider().getMaxHeight(center.getWorld()),
             center.getZ() + offsetZ,
             360 * RANDOM.nextFloat() - 180,
             0
@@ -195,7 +195,7 @@ public class RandomTeleport implements IConf {
 
     // Returns an appropriate elevation for a given location in the nether, or -1 if none is found
     private double getNetherYAt(final Location location) {
-        for (int y = 32; y < ess.getWorldInfoProvider().getMaxSafeHeight(location.getWorld()); ++y) {
+        for (int y = 32; y < ess.getWorldInfoProvider().getMaxHeight(location.getWorld()); ++y) {
             if (!LocationUtil.isBlockUnsafe(ess, location.getWorld(), location.getBlockX(), y, location.getBlockZ())) {
                 return y;
             }
@@ -204,6 +204,6 @@ public class RandomTeleport implements IConf {
     }
 
     private boolean isValidRandomLocation(final Location location) {
-        return location.getBlockY() > ess.getWorldInfoProvider().getMinSafeHeight(location.getWorld()) && !this.getExcludedBiomes().contains(location.getBlock().getBiome());
+        return location.getBlockY() > ess.getWorldInfoProvider().getMinHeight(location.getWorld()) && !this.getExcludedBiomes().contains(location.getBlock().getBiome());
     }
 }

Essentials/src/main/java/com/earth2me/essentials/commands/Commandtop.java

@@ -22,7 +22,7 @@ public class Commandtop extends EssentialsCommand {
         final int topZ = user.getLocation().getBlockZ();
         final float pitch = user.getLocation().getPitch();
         final float yaw = user.getLocation().getYaw();
-        final Location unsafe = new Location(user.getWorld(), topX, ess.getWorldInfoProvider().getMaxSafeHeight(user.getWorld()), topZ, yaw, pitch);
+        final Location unsafe = new Location(user.getWorld(), topX, ess.getWorldInfoProvider().getMaxHeight(user.getWorld()), topZ, yaw, pitch);
         final Location safe = LocationUtil.getSafeDestination(ess, unsafe);
         final CompletableFuture<Boolean> future = new CompletableFuture<>();
         future.thenAccept(success -> {

Essentials/src/main/java/com/earth2me/essentials/utils/LocationUtil.java

@@ -97,7 +97,7 @@ public final class LocationUtil {
     }
 
     public static boolean isBlockAboveAir(IEssentials ess, final World world, final int x, final int y, final int z) {
-        return y > ess.getWorldInfoProvider().getMaxSafeHeight(world) || HOLLOW_MATERIALS.contains(world.getBlockAt(x, y - 1, z).getType());
+        return y > ess.getWorldInfoProvider().getMaxHeight(world) || HOLLOW_MATERIALS.contains(world.getBlockAt(x, y - 1, z).getType());
     }
 
     public static boolean isBlockOutsideWorldBorder(final World world, final int x, final int z) {
@@ -203,8 +203,9 @@ public final class LocationUtil {
             throw new Exception(tl("destinationNotSet"));
         }
         final World world = loc.getWorld();
-        final int worldMinY = ess.getWorldInfoProvider().getMinSafeHeight(world);
+        final int worldMinY = ess.getWorldInfoProvider().getMinHeight(world);
-        final int worldMaxY = ess.getWorldInfoProvider().getMaxSafeHeight(world);
+        final int worldLogicalY = ess.getWorldInfoProvider().getLogicalHeight(world);
+        final int worldMaxY = loc.getBlockY() < worldLogicalY ? worldLogicalY : ess.getWorldInfoProvider().getMaxHeight(world);
         int x = loc.getBlockX();
         int y = (int) Math.round(loc.getY());
         int z = loc.getBlockZ();

providers/BaseProviders/src/main/java/net/ess3/provider/WorldInfoProvider.java

@@ -4,18 +4,27 @@ import org.bukkit.World;
 
 public interface WorldInfoProvider extends Provider {
     /**
-     * Gets the maximum safe height for teleportation.
+     * Gets the maximum height of the world.
      *
-     * @param world The world of which to check the maximum safe height.
+     * @param world The world of which to check the maximum height.
-     * @return The maximum safe height for teleportation
+     * @return The maximum height of the world.
      */
-    int getMaxSafeHeight(World world);
+    int getMaxHeight(World world);
 
     /**
-     * Gets the minimum safe height for teleportation.
+     * Gets the "logical" height of the world, which is the highest Y level at which vanilla spawns Nether portals and
+     * performs chorus fruit teleports.
      *
-     * @param world The world of which to check the base height.
+     * @param world The world of which to check the logical height.
+     * @return The logical height of the world.
+     */
+    int getLogicalHeight(World world);
+
+    /**
+     * Gets the minimum height of the world.
+     *
+     * @param world The world of which to check the minimum height.
      * @return The minimum safe height for teleportation
      */
-    int getMinSafeHeight(World world);
+    int getMinHeight(World world);
 }

providers/BaseProviders/src/main/java/net/ess3/provider/providers/FixedHeightWorldInfoProvider.java

@@ -6,16 +6,24 @@ import org.bukkit.World;
 public class FixedHeightWorldInfoProvider implements WorldInfoProvider {
     @Override
     public String getDescription() {
-        return "World info provider for fixed world heights";
+        return "Fixed world info provider for pre-1.16";
     }
 
     @Override
-    public int getMaxSafeHeight(World world) {
+    public int getMaxHeight(World world) {
+        // Method has existed since Beta 1.7 (yes, *beta*)
+        return world.getMaxHeight();
+    }
+
+    @Override
+    public int getLogicalHeight(World world) {
+        // This mirrors the vanilla behaviour up until Minecraft 1.16
         return world.getEnvironment() == World.Environment.NETHER ? 128 : 256;
     }
 
     @Override
-    public int getMinSafeHeight(World world) {
+    public int getMinHeight(World world) {
+        // Worlds could not go below 0 until Minecraft 1.16
         return 0;
     }
 }

providers/BaseProviders/src/main/java/net/ess3/provider/providers/ModernDataWorldInfoProvider.java

@@ -0,0 +1,26 @@
+package net.ess3.provider.providers;
+
+import net.ess3.provider.WorldInfoProvider;
+import org.bukkit.World;
+
+public class ModernDataWorldInfoProvider implements WorldInfoProvider {
+    @Override
+    public String getDescription() {
+        return "API world info provider for data-driven worldgen for 1.17.1+";
+    }
+
+    @Override
+    public int getMaxHeight(World world) {
+        return world.getMaxHeight();
+    }
+
+    @Override
+    public int getLogicalHeight(World world) {
+        return world.getLogicalHeight();
+    }
+
+    @Override
+    public int getMinHeight(World world) {
+        return world.getMinHeight();
+    }
+}

providers/BaseProviders/src/main/java/net/ess3/provider/providers/ModernWorldInfoProvider.java

@@ -1,21 +0,0 @@
-package net.ess3.provider.providers;
-
-import net.ess3.provider.WorldInfoProvider;
-import org.bukkit.World;
-
-public class ModernWorldInfoProvider implements WorldInfoProvider {
-    @Override
-    public String getDescription() {
-        return "World info provider for data-driven world generation";
-    }
-
-    @Override
-    public int getMaxSafeHeight(World world) {
-        return world.getLogicalHeight();
-    }
-
-    @Override
-    public int getMinSafeHeight(World world) {
-        return world.getMinHeight();
-    }
-}

providers/NMSReflectionProvider/src/main/java/net/ess3/nms/refl/providers/ReflDataWorldInfoProvider.java

@@ -0,0 +1,31 @@
+package net.ess3.nms.refl.providers;
+
+import net.ess3.provider.WorldInfoProvider;
+import org.bukkit.World;
+
+public class ReflDataWorldInfoProvider implements WorldInfoProvider {
+    @Override
+    public String getDescription() {
+        return "NMS world info provider for data-driven worldgen for 1.16.x";
+    }
+
+    @Override
+    public int getMaxHeight(World world) {
+        // Method has existed since Beta 1.7 (yes, *beta*)
+        return world.getMaxHeight();
+    }
+
+    @Override
+    public int getLogicalHeight(World world) {
+        // TODO: THIS IS INCORRECT
+        // This mirrors the vanilla behaviour up until Minecraft 1.16
+        return world.getEnvironment() == World.Environment.NETHER ? 128 : 256;
+    }
+
+    @Override
+    public int getMinHeight(World world) {
+        // TODO: THIS IS INCORRECT
+        // Worlds could not go below 0 until Minecraft 1.16
+        return 0;
+    }
+}