Add VariantSelector

BauSystem/BauSystem_RegionDynamic/src/de/steamwar/bausystem/region/dynamic/variants/VariantSelector.java

@@ -19,8 +19,13 @@
 
 package de.steamwar.bausystem.region.dynamic.variants;
 
+import lombok.NonNull;
+
 import java.io.File;
+import java.time.LocalDate;
+import java.util.Objects;
 import java.util.Optional;
+import java.util.Random;
 
 public interface VariantSelector {
 
@@ -29,4 +34,35 @@ public interface VariantSelector {
     default VariantSelector or(VariantSelector other) {
         return (minX, minZ) -> selectVariant(minX, minZ).or(() -> other.selectVariant(minX, minZ));
     }
+
+    static VariantSelector AtDate(int day, int month, File file) {
+        return (minX, minZ) -> {
+            LocalDate date = LocalDate.now();
+            if (date.getDayOfMonth() == day && date.getMonthValue() == month) {
+                return Optional.of(file);
+            } else {
+                return Optional.empty();
+            }
+        };
+    }
+
+    static VariantSelector File(@NonNull File file) {
+        return (minX, minZ) -> Optional.of(file);
+    }
+
+    static VariantSelector StableVariants(@NonNull File directory) {
+        File[] files = directory.listFiles();
+        return (minX, minZ) -> {
+            Random rand = new Random(Objects.hash(minX, minZ));
+            return Optional.of(files[rand.nextInt(files.length)]);
+        };
+    }
+
+    static VariantSelector RandomVariants(@NonNull File directory) {
+        File[] files = directory.listFiles();
+        Random rand = new Random();
+        return (minX, minZ) -> {
+            return Optional.of(files[rand.nextInt(files.length)]);
+        };
+    }
 }