Add plugin.yml discovery by traversal

src/de/steamwar/linkage/LinkageProcessor.java

@@ -38,6 +38,8 @@ import javax.tools.Diagnostic;
 import java.io.*;
 import java.io.Writer;
 import java.lang.annotation.Annotation;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.*;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
@@ -88,22 +90,23 @@ public class LinkageProcessor extends AbstractProcessor {
         mainClass();
     }
 
+    @SneakyThrows
     private void mainClass() {
         File file = new File(System.getProperty("user.dir"));
-        String subModuleName = file.getName();
-        if (subModuleName.contains(".")) subModuleName = subModuleName.substring(0, subModuleName.indexOf('.'));
-
-        Optional<String> main = getMainName(new File(file, "src/plugin.yml"));
-        if (!main.isPresent()) main = getMainName(new File(file, "src/main/resources/plugin.yml"));
-        if (!main.isPresent()) main = getMainName(new File(file, subModuleName + "_Core/src/plugin.yml"));
-        if (!main.isPresent()) main = getMainName(new File(file, subModuleName + "_Core/src/main/resources/plugin.yml"));
-        if (!main.isPresent()) main = getMainName(new File(file, subModuleName + "_Main/src/plugin.yml"));
-        if (!main.isPresent()) main = getMainName(new File(file, subModuleName + "_Main/src/main/resources/plugin.yml"));
-        if (!main.isPresent()) {
+        Optional<File> pluginYMLFile = Files.walk(file.toPath())
+                .map(Path::toFile)
+                .filter(f -> f.getName().equals("plugin.yml"))
+                .findFirst();
+        if (!pluginYMLFile.isPresent()) {
             messager.printMessage(Diagnostic.Kind.ERROR, "Could not find plugin.yml");
             return;
         }
-        pluginMain = main.get();
+        Optional<String> mainName = getMainName(pluginYMLFile.get());
+        if (!mainName.isPresent()) {
+            messager.printMessage(Diagnostic.Kind.ERROR, "Could not find main class in plugin.yml");
+            return;
+        }
+        pluginMain = mainName.get();
     }
 
     @SneakyThrows