Stub of the DMaaP Client 2.0 implementation

This is untested. Treat it as a proof of concept.

Change-Id: Ieeef7c9481324984c9772b216d001254dec11ae9
Issue-ID: DCAEGEN2-1368
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>

6 files changed, 191 insertions, 9 deletions

diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/api/DmaapClientFactory.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/api/DmaapClientFactory.java
index 48e6f5d1..7eb72f7c 100644
--- a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/api/DmaapClientFactory.java
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/api/DmaapClientFactory.java
@@ -20,23 +20,34 @@
 
 package org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.api;
 
+import com.google.gson.Gson;
+import io.vavr.Lazy;
+import org.jetbrains.annotations.NotNull;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClient;
 import org.onap.dcaegen2.services.sdk.rest.services.annotations.ExperimentalApi;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.impl.MessageRouterClientImpl;
 
 /**
+ * <b>WARNING</b>: This is a proof-of-concept. It is untested. API may change or be removed.  Use at your own risk.
+ * You've been warned.
+ *
  * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
  * @since 1.1.4
  */
 @ExperimentalApi
 public final class DmaapClientFactory {
 
+    private static final Lazy<MessageRouterClientImpl> THE_CLIENT = Lazy.of(() ->
+            new MessageRouterClientImpl(RxHttpClient.create(), new Gson()));
+
     private DmaapClientFactory() {
     }
 
-    public static MessageRouterPublisher createMessageRouterPublisher() {
-        throw new UnsupportedOperationException("not implemented yet");
+    public static @NotNull MessageRouterPublisher createMessageRouterPublisher() {
+        return THE_CLIENT.get();
     }
 
-    public static MessageRouterSubscriber createMessageRouterSubscriber() {
-        throw new UnsupportedOperationException("not implemented yet");
+    public static @NotNull MessageRouterSubscriber createMessageRouterSubscriber() {
+        return THE_CLIENT.get();
     }
 }
diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/impl/MessageRouterClientImpl.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/impl/MessageRouterClientImpl.java
new file mode 100644
index 00000000..0ef06201
--- /dev/null
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/impl/MessageRouterClientImpl.java
@@ -0,0 +1,126 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.impl;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import io.netty.buffer.ByteBuf;
+import io.vavr.collection.HashMap;
+import java.nio.charset.StandardCharsets;
+import java.time.Duration;
+import org.jetbrains.annotations.NotNull;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpHeaders;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpMethod;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.HttpResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.ImmutableHttpRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RequestBody;
+import org.onap.dcaegen2.services.sdk.rest.services.adapters.http.RxHttpClient;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.api.MessageRouterPublisher;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.api.MessageRouterSubscriber;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.ImmutableMessageRouterPublishResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.ImmutableMessageRouterSubscribeResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.MessageRouterPublishRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.MessageRouterPublishResponse;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.MessageRouterSubscribeRequest;
+import org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model.MessageRouterSubscribeResponse;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+// TODO: This is a PoC. It's untested.
+public class MessageRouterClientImpl implements MessageRouterPublisher, MessageRouterSubscriber {
+
+    private static final Duration WINDOW_MAX_TIME = Duration.ofSeconds(1);
+    private static final int WINDOW_MAX_SIZE = 512;
+    private final RxHttpClient httpClient;
+    private final Gson gson;
+
+    public MessageRouterClientImpl(RxHttpClient httpClient, Gson gson) {
+        this.httpClient = httpClient;
+        this.gson = gson;
+    }
+
+    @Override
+    public Flux<MessageRouterPublishResponse> put(
+            MessageRouterPublishRequest request,
+            Flux<? extends JsonElement> items) {
+        return items.windowTimeout(WINDOW_MAX_SIZE, WINDOW_MAX_TIME).flatMap(subItems ->
+                subItems.collect(JsonArray::new, JsonArray::add)
+                        .filter(arr -> arr.size() > 0)
+                        .map(RequestBody::fromJson)
+                        .flatMap(body -> httpClient.call(buildPostHttpRequest(request, body)))
+                        .map(this::buildPutResponse));
+    }
+
+    @Override
+    public Mono<MessageRouterSubscribeResponse> get(MessageRouterSubscribeRequest request) {
+        return httpClient.call(buildGetHttpRequest(request)).map(this::buildGetResponse);
+    }
+
+    private @NotNull MessageRouterPublishResponse buildPutResponse(HttpResponse httpResponse) {
+        final ImmutableMessageRouterPublishResponse.Builder builder =
+                ImmutableMessageRouterPublishResponse.builder();
+        return httpResponse.successful()
+                ? builder.build()
+                : builder.failReason(extractFailReason(httpResponse)).build();
+    }
+
+    private @NotNull MessageRouterSubscribeResponse buildGetResponse(HttpResponse httpResponse) {
+        final ImmutableMessageRouterSubscribeResponse.Builder builder =
+                ImmutableMessageRouterSubscribeResponse.builder();
+        return httpResponse.successful()
+                ? builder.items(httpResponse.bodyAsJson(StandardCharsets.UTF_8, gson, JsonArray.class)).build()
+                : builder.failReason(extractFailReason(httpResponse)).build();
+    }
+
+    private String extractFailReason(HttpResponse httpResponse) {
+        return String.format("%d %s%n%s", httpResponse.statusCode(), httpResponse.statusReason(),
+                httpResponse.bodyAsString());
+    }
+
+    private @NotNull HttpRequest buildPostHttpRequest(MessageRouterPublishRequest request, RequestBody body) {
+        return ImmutableHttpRequest.builder()
+                .method(HttpMethod.POST)
+                .url(request.sinkDefinition().topicUrl())
+                .diagnosticContext(request.diagnosticContext())
+                .customHeaders(HashMap.of(HttpHeaders.CONTENT_TYPE, request.contentType()))
+                .body(body)
+                .build();
+    }
+
+    private @NotNull HttpRequest buildGetHttpRequest(MessageRouterSubscribeRequest request) {
+        return ImmutableHttpRequest.builder()
+                .method(HttpMethod.GET)
+                .url(buildSubscribeUrl(request))
+                .diagnosticContext(request.diagnosticContext())
+                .build();
+    }
+
+    private String buildSubscribeUrl(MessageRouterSubscribeRequest request) {
+        return String.format("%s/%s/%s", request.sourceDefinition().topicUrl(), request.consumerGroup(), request.consumerId());
+    }
+}
diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/Constants.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/Constants.java
new file mode 100644
index 00000000..1e1ce955
--- /dev/null
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/Constants.java
@@ -0,0 +1,35 @@
+/*
+ * ============LICENSE_START====================================
+ * DCAEGEN2-SERVICES-SDK
+ * =========================================================
+ * Copyright (C) 2019 Nokia. All rights reserved.
+ * =========================================================
+ * 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.
+ * ============LICENSE_END=====================================
+ */
+
+package org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model;
+
+import java.util.UUID;
+
+/**
+ * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
+ * @since March 2019
+ */
+final class Constants {
+
+    private Constants() {
+    }
+
+    static final String CLASS_LOADER_SCOPED_UNIQUE_ID = UUID.randomUUID().toString();
+}
diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/DmaapRequest.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/DmaapRequest.java
index f2a7193e..2bed4c9f 100644
--- a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/DmaapRequest.java
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/DmaapRequest.java
@@ -34,5 +34,4 @@ public interface DmaapRequest {
     default RequestDiagnosticContext diagnosticContext() {
         return RequestDiagnosticContext.create();
     }
-
 }
diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterPublishRequest.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterPublishRequest.java
index 0d507865..4c816f31 100644
--- a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterPublishRequest.java
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterPublishRequest.java
@@ -23,7 +23,6 @@ package org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model;
 import org.immutables.value.Value;
 import org.onap.dcaegen2.services.sdk.model.streams.dmaap.MessageRouterSink;
 import org.onap.dcaegen2.services.sdk.rest.services.annotations.ExperimentalApi;
-import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
 
 /**
  * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
@@ -34,4 +33,9 @@ import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnos
 public interface MessageRouterPublishRequest extends DmaapRequest {
 
     MessageRouterSink sinkDefinition();
+
+    @Value.Default
+    default String contentType() {
+        return "application/json";
+    }
 }
diff --git a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterSubscribeRequest.java b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterSubscribeRequest.java
index 49dca603..f32fd0ee 100644
--- a/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterSubscribeRequest.java
+++ b/rest-services/dmaap-client/src/main/java/org/onap/dcaegen2/services/sdk/rest/services/dmaap/client/model/MessageRouterSubscribeRequest.java
@@ -17,14 +17,13 @@
  * limitations under the License.
  * ============LICENSE_END=====================================
  */
-
 package org.onap.dcaegen2.services.sdk.rest.services.dmaap.client.model;
 
+import java.time.Duration;
 import org.immutables.value.Value;
+import org.jetbrains.annotations.Nullable;
 import org.onap.dcaegen2.services.sdk.model.streams.dmaap.MessageRouterSource;
 import org.onap.dcaegen2.services.sdk.rest.services.annotations.ExperimentalApi;
-import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnosticContext;
-
 
 /**
  * @author <a href="mailto:piotr.jaszczyk@nokia.com">Piotr Jaszczyk</a>
@@ -35,4 +34,12 @@ import org.onap.dcaegen2.services.sdk.rest.services.model.logging.RequestDiagnos
 public interface MessageRouterSubscribeRequest extends DmaapRequest {
 
     MessageRouterSource sourceDefinition();
+
+    String consumerGroup();
+
+    @Nullable Duration timeout();
+
+    default String consumerId() {
+        return Constants.CLASS_LOADER_SCOPED_UNIQUE_ID;
+    }
 }