1 files changed, 35 insertions, 5 deletions

diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaFrontend.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaFrontend.java
index bccd4a8..fa44676 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaFrontend.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaFrontend.java
@@ -1,25 +1,55 @@
 package org.zwobble.couscous.frontends.java;
 
+import com.google.common.collect.Multimaps;
+import org.zwobble.couscous.Frontend;
+import org.zwobble.couscous.ast.ClassNode;
+import org.zwobble.couscous.ast.Node;
+import org.zwobble.couscous.ast.VariableDeclaration;
+import org.zwobble.couscous.ast.VariableNode;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.zwobble.couscous.Frontend;
-import org.zwobble.couscous.ast.ClassNode;
-import org.zwobble.couscous.util.ExtraLists;
+import static org.zwobble.couscous.ast.structure.NodeStructure.descendantNodesAndSelf;
+import static org.zwobble.couscous.util.Casts.tryCast;
+import static org.zwobble.couscous.util.ExtraLists.eagerFlatMap;
+import static org.zwobble.couscous.util.ExtraLists.flatMap;
+import static org.zwobble.couscous.util.ExtraStreams.toStream;
 
 public class JavaFrontend implements Frontend {
     @Override
     public List<ClassNode> readSourceDirectory(Path directoryPath) throws IOException {
-        return ExtraLists.flatMap(
+        List<ClassNode> classNodes = flatMap(
             findJavaFiles(directoryPath),
             javaFile -> JavaReader.readClassFromFile(directoryPath, javaFile));
+        //ensureDeclarationsAreUnique(classNodes);
+        return classNodes;
     }
-    
+
     private Stream<Path> findJavaFiles(Path directoryPath) throws IOException {
         return Files.walk(directoryPath)
             .filter(path -> path.toFile().isFile() && path.toString().endsWith(".java"));
     }
+
+    private void ensureDeclarationsAreUnique(List<ClassNode> classNodes) {
+        List<VariableDeclaration> declarations = eagerFlatMap(classNodes, this::findDeclarations);
+        Multimaps.index(declarations, declaration -> declaration.getId())
+            .asMap()
+            .forEach((id, declarationsWithId) -> {
+                if (declarationsWithId.size() > 1) {
+                    throw new RuntimeException("Declaration " + id + " is declared more than once");
+                }
+            });
+    }
+
+    private List<VariableDeclaration> findDeclarations(Node root) {
+        return descendantNodesAndSelf(root)
+            .flatMap(node -> toStream(tryCast(VariableNode.class, node)
+                .map(VariableNode::getDeclaration)))
+            .collect(Collectors.toList());
+    }
 }
\ No newline at end of file