create simple property API

common/api/src/main/java/com/dfsek/terra/api/properties/Context.java

@@ -0,0 +1,21 @@
+package com.dfsek.terra.api.properties;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Context {
+    private final Map<Class<? extends Properties>, Properties> map = new HashMap<>();
+
+    @SuppressWarnings("unchecked")
+    public <T extends Properties> T get(Class<T> clazz) {
+        return (T) map.computeIfAbsent(clazz, k -> {
+            throw new IllegalArgumentException("No properties registered for class " + clazz.getCanonicalName());
+        });
+    }
+
+    public Context put(Properties properties) {
+        if(map.containsKey(properties.getClass())) throw new IllegalArgumentException("Property for class " + properties.getClass().getCanonicalName() + " already registered.");
+        map.put(properties.getClass(), properties);
+        return this;
+    }
+}

common/api/src/main/java/com/dfsek/terra/api/properties/Properties.java

@@ -0,0 +1,4 @@
+package com.dfsek.terra.api.properties;
+
+public interface Properties {
+}

common/api/src/main/java/com/dfsek/terra/api/properties/PropertyHolder.java

@@ -0,0 +1,5 @@
+package com.dfsek.terra.api.properties;
+
+public interface PropertyHolder {
+    Context getContext();
+}