create MetaValuePreprocessor

common/addons/language-yaml/src/main/java/com/dfsek/terra/addons/yaml/YamlAddon.java

@@ -23,6 +23,6 @@ public class YamlAddon extends TerraAddon implements EventListener {
     }
 
     public void loadYamlConfigs(ConfigurationDiscoveryEvent event) {
-        event.getLoader().open("", ".yml").thenEntries(entries -> entries.forEach(entry -> event.register(new YamlConfiguration(entry.getValue(), entry.getKey()))));
+        event.getLoader().open("", ".yml").thenEntries(entries -> entries.forEach(entry -> event.register(entry.getKey(), new YamlConfiguration(entry.getValue(), entry.getKey()))));
     }
 }

common/api/build.gradle.kts

@@ -15,8 +15,8 @@ group = "com.dfsek.terra.common"
 dependencies {
     "shadedApi"("com.dfsek:Paralithic:0.4.0")
 
-    "shadedApi"("com.dfsek.tectonic:common:2.1.1")
+    "shadedApi"("com.dfsek.tectonic:common:2.1.2")
-    "shadedApi"("com.dfsek.tectonic:yaml:2.1.1")
+    "shadedApi"("com.dfsek.tectonic:yaml:2.1.2")
 
     "shadedApi"("net.jafama:jafama:2.3.2")
     "shadedApi"("org.yaml:snakeyaml:1.27")

common/api/src/main/java/com/dfsek/terra/api/event/events/config/ConfigurationDiscoveryEvent.java

@@ -5,6 +5,7 @@ import com.dfsek.terra.api.config.ConfigPack;
 import com.dfsek.terra.api.config.Loader;
 import com.dfsek.terra.api.event.events.PackEvent;
 
+import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 
 /**
@@ -17,9 +18,9 @@ public class ConfigurationDiscoveryEvent implements PackEvent {
     private final ConfigPack pack;
     private final Loader loader;
 
-    private final Consumer<Configuration> consumer;
+    private final BiConsumer<String, Configuration> consumer;
 
-    public ConfigurationDiscoveryEvent(ConfigPack pack, Loader loader, Consumer<Configuration> consumer) {
+    public ConfigurationDiscoveryEvent(ConfigPack pack, Loader loader, BiConsumer<String, Configuration> consumer) {
         this.pack = pack;
         this.loader = loader;
         this.consumer = consumer;
@@ -34,7 +35,7 @@ public class ConfigurationDiscoveryEvent implements PackEvent {
         return loader;
     }
 
-    public void register(Configuration config) {
+    public void register(String identifier, Configuration config) {
-        consumer.accept(config);
+        consumer.accept(identifier, config);
     }
 }

common/implementation/src/main/java/com/dfsek/terra/config/pack/ConfigPackImpl.java

@@ -18,6 +18,7 @@ import com.dfsek.terra.api.config.ConfigFactory;
 import com.dfsek.terra.api.config.ConfigPack;
 import com.dfsek.terra.api.config.ConfigType;
 import com.dfsek.terra.api.config.Loader;
+import com.dfsek.terra.api.config.meta.Meta;
 import com.dfsek.terra.api.event.events.config.ConfigurationDiscoveryEvent;
 import com.dfsek.terra.api.event.events.config.ConfigurationLoadEvent;
 import com.dfsek.terra.api.event.events.config.pack.ConfigPackPostLoadEvent;
@@ -40,6 +41,7 @@ import com.dfsek.terra.config.fileloaders.FolderLoader;
 import com.dfsek.terra.config.fileloaders.ZIPLoader;
 import com.dfsek.terra.config.loaders.GenericTemplateSupplierLoader;
 import com.dfsek.terra.config.loaders.config.BufferedImageLoader;
+import com.dfsek.terra.config.preprocessor.MetaValuePreprocessor;
 import com.dfsek.terra.config.prototype.ProtoConfig;
 import com.dfsek.terra.registry.CheckedRegistryImpl;
 import com.dfsek.terra.registry.OpenRegistryImpl;
@@ -234,13 +236,16 @@ public class ConfigPackImpl implements ConfigPack {
             varScope.create(var.getKey(), var.getValue());
         }
 
-        List<Configuration> configurations = new ArrayList<>();
+        Map<String, Configuration> configurations = new HashMap<>();
 
-        main.getEventManager().callEvent(new ConfigurationDiscoveryEvent(this, loader, configurations::add)); // Create all the configs.
+        main.getEventManager().callEvent(new ConfigurationDiscoveryEvent(this, loader, configurations::put)); // Create all the configs.
+
+        selfLoader.registerPreprocessor(Meta.class, new MetaValuePreprocessor(configurations));
+        abstractConfigLoader.registerPreprocessor(Meta.class, new MetaValuePreprocessor(configurations));
 
         Map<ConfigType<? extends ConfigTemplate, ?>, List<Configuration>> configs = new HashMap<>();
 
-        for(Configuration configuration : configurations) { // Sort the configs
+        for(Configuration configuration : configurations.values()) { // Sort the configs
             ProtoConfig config = new ProtoConfig();
             selfLoader.load(config, configuration);
             configs.computeIfAbsent(config.getType(), configType -> new ArrayList<>()).add(configuration);

common/implementation/src/main/java/com/dfsek/terra/config/preprocessor/MetaValuePreprocessor.java

@@ -0,0 +1,44 @@
+package com.dfsek.terra.config.preprocessor;
+
+import com.dfsek.tectonic.config.Configuration;
+import com.dfsek.tectonic.exception.LoadException;
+import com.dfsek.tectonic.loading.ConfigLoader;
+import com.dfsek.tectonic.preprocessor.Result;
+import com.dfsek.tectonic.preprocessor.ValuePreprocessor;
+import com.dfsek.terra.api.config.meta.Meta;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.AnnotatedType;
+import java.util.Map;
+
+public class MetaValuePreprocessor implements ValuePreprocessor<Meta> {
+    private final Map<String, Configuration> configs;
+
+    public MetaValuePreprocessor(Map<String, Configuration> configs) {
+        this.configs = configs;
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public @NotNull <T> Result<T> process(AnnotatedType t, T c, ConfigLoader configLoader, Meta annotation) {
+        if(c instanceof String) {
+            String value = ((String) c).trim();
+            if(value.startsWith("$")) { // it's a meta value.
+                String raw = value.substring(1);
+                int sep = raw.indexOf(':');
+                String file = raw.substring(0, sep);
+                String key = raw.substring(sep + 1);
+
+                if(!configs.containsKey(file)) throw new LoadException("Cannot fetch metavalue: No such config: " + file);
+
+                Configuration config = configs.get(file);
+
+                if(!config.contains(key))
+                    throw new LoadException("Cannot fetch metavalue: No such key " + key + " in configuration " + config.getName());
+
+                return (Result<T>) Result.overwrite(config.get(key));
+            }
+        }
+        return Result.noOp();
+    }
+}