Added Simple Sharing feature implementation

data-catalog-api/server/simple-sharing/src/main/java/org/apache/airavata/datacatalog/api/sharing/SharingServiceImpl.java

@@ -0,0 +1,81 @@
+package org.apache.airavata.datacatalog.api.sharing;
+
+import io.grpc.stub.StreamObserver;
+import org.apache.airavata.datacatalog.api.*;
+import org.apache.airavata.datacatalog.api.sharing.exception.SharingException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+
+@Service
+public class SharingServiceImpl extends SharingServiceGrpc.SharingServiceImplBase {
+
+    private final SimpleSharingManagerImpl sharingManager;
+
+    @Autowired
+    public SharingServiceImpl(SimpleSharingManagerImpl sharingManager) {
+        this.sharingManager = sharingManager;
+    }
+
+    @Override
+    public void grantPermissionToUser(GrantPermissionRequest request, StreamObserver<GrantPermissionResponse> responseObserver) {
+        try {
+            sharingManager.grantPermissionToUser(
+                    request.getUserInfo(),
+                    request.getDataProduct(),
+                    request.getPermission(),
+                    request.hasSharedByUser() ? request.getSharedByUser() : null
+            );
+            responseObserver.onNext(GrantPermissionResponse.newBuilder().build());
+            responseObserver.onCompleted();
+        } catch (SharingException e) {
+            responseObserver.onError(e);
+        }
+    }
+
+    @Override
+    public void revokePermissionFromUser(RevokePermissionRequest request, StreamObserver<RevokePermissionResponse> responseObserver) {
+        try {
+            sharingManager.revokePermissionFromUser(
+                    request.getUserInfo(),
+                    request.getDataProduct(),
+                    request.getPermission()
+            );
+            responseObserver.onNext(RevokePermissionResponse.newBuilder().build());
+            responseObserver.onCompleted();
+        } catch (SharingException e) {
+            responseObserver.onError(e);
+        }
+    }
+
+    @Override
+    public void grantPermissionToGroup(GrantPermissionToGroupRequest request, StreamObserver<GrantPermissionResponse> responseObserver) {
+        try {
+            sharingManager.grantPermissionToGroup(
+                    request.getGroupInfo(),
+                    request.getDataProduct(),
+                    request.getPermission(),
+                    request.hasSharedByUser() ? request.getSharedByUser() : null
+            );
+            responseObserver.onNext(GrantPermissionResponse.newBuilder().build());
+            responseObserver.onCompleted();
+        } catch (SharingException e) {
+            responseObserver.onError(e);
+        }
+    }
+
+    @Override
+    public void revokePermissionFromGroup(RevokePermissionFromGroupRequest request, StreamObserver<RevokePermissionResponse> responseObserver) {
+        try {
+            sharingManager.revokePermissionFromGroup(
+                    request.getGroupInfo(),
+                    request.getDataProduct(),
+                    request.getPermission()
+            );
+            responseObserver.onNext(RevokePermissionResponse.newBuilder().build());
+            responseObserver.onCompleted();
+        } catch (SharingException e) {
+            responseObserver.onError(e);
+        }
+    }
+}