1 files changed, 119 insertions, 0 deletions
diff --git a/src/main/java/org/onap/dcaegen2/services/pmmapper/datarouter/DeliveryHandler.java b/src/main/java/org/onap/dcaegen2/services/pmmapper/datarouter/DeliveryHandler.java
new file mode 100644
index 0000000..4d6af29
--- /dev/null
+++ b/src/main/java/org/onap/dcaegen2/services/pmmapper/datarouter/DeliveryHandler.java
@@ -0,0 +1,119 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2019 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.dcaegen2.services.pmmapper.datarouter;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonParseException;
+import io.undertow.util.HeaderValues;
+import lombok.Data;
+import lombok.NonNull;
+
+import org.onap.dcaegen2.services.pmmapper.exceptions.NoMetadataException;
+import org.onap.dcaegen2.services.pmmapper.model.EventMetadata;
+import org.onap.dcaegen2.services.pmmapper.model.Event;
+import io.undertow.server.HttpHandler;
+import io.undertow.server.HttpServerExchange;
+import io.undertow.util.StatusCodes;
+
+import org.onap.dcaegen2.services.pmmapper.utils.HttpServerExchangeAdapter;
+import org.onap.dcaegen2.services.pmmapper.utils.RequiredFieldDeserializer;
+import org.onap.logging.ref.slf4j.ONAPLogAdapter;
+import org.slf4j.LoggerFactory;
+import org.slf4j.MDC;
+
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Provides an undertow HttpHandler to be used as an endpoint for data router to send events to.
+ */
+@Data
+public class DeliveryHandler implements HttpHandler {
+
+    public static final String METADATA_HEADER = "X-DMAAP-DR-META";
+    public static final String PUB_ID_HEADER = "X-DMAAP-DR-PUBLISH-ID";
+
+    private static final ONAPLogAdapter logger = new ONAPLogAdapter(LoggerFactory.getLogger(DeliveryHandler.class));
+
+    private static final String BAD_METADATA_MESSAGE = "Malformed Metadata.";
+    private static final String NO_METADATA_MESSAGE = "Missing Metadata.";
+
+    private Gson metadataBuilder;
+
+    @NonNull
+    private EventReceiver eventReceiver;
+
+    /**
+     * @param eventReceiver receiver for any inbound events.
+     */
+    public DeliveryHandler(EventReceiver eventReceiver) {
+        this.eventReceiver = eventReceiver;
+        this.metadataBuilder = new GsonBuilder()
+                .registerTypeAdapter(EventMetadata.class, new RequiredFieldDeserializer<EventMetadata>())
+                .create();
+    }
+
+    private EventMetadata getMetadata(HttpServerExchange httpServerExchange) throws NoMetadataException {
+        String metadata = Optional.ofNullable(httpServerExchange.getRequestHeaders()
+                .get(METADATA_HEADER))
+                .map((HeaderValues headerValues) -> headerValues.get(0))
+                .orElseThrow(() -> new NoMetadataException("Metadata Not found"));
+        return metadataBuilder.fromJson(metadata, EventMetadata.class);
+    }
+
+    /**
+     * Receives inbound requests, verifies that required headers are valid
+     * and passes an Event onto the eventReceiver.
+     * The forwarded httpServerExchange response is the responsibility of the eventReceiver.
+     *
+     * @param httpServerExchange inbound http server exchange.
+     */
+    @Override
+    public void handleRequest(HttpServerExchange httpServerExchange) {
+        try{
+            logger.entering(new HttpServerExchangeAdapter(httpServerExchange));
+            try {
+                Map<String,String> mdc = MDC.getCopyOfContextMap();
+                EventMetadata metadata = getMetadata(httpServerExchange);
+                String publishIdentity = httpServerExchange.getRequestHeaders().get(PUB_ID_HEADER).getFirst();
+                httpServerExchange.getRequestReceiver()
+                        .receiveFullString((callbackExchange, body) ->
+                                httpServerExchange.dispatch(() ->
+                                        eventReceiver.receive(new Event(
+                                                callbackExchange, body, metadata, mdc, publishIdentity)))
+                        );
+            } catch (NoMetadataException exception) {
+                logger.unwrap().info("Bad Request: no metadata found under '{}' header.", METADATA_HEADER, exception);
+                httpServerExchange.setStatusCode(StatusCodes.BAD_REQUEST)
+                        .getResponseSender()
+                        .send(NO_METADATA_MESSAGE);
+            } catch (JsonParseException exception) {
+                logger.unwrap().info("Bad Request: Failure to parse metadata", exception);
+                httpServerExchange.setStatusCode(StatusCodes.BAD_REQUEST)
+                        .getResponseSender()
+                        .send(BAD_METADATA_MESSAGE);
+            }
+        } finally {
+            logger.exiting();
+        }
+    }
+}