/**
* TestRunner provides static factory for quick setup of Samza environment for testing Low level api and High level api , users can configure input streams 
* they consume from and output streams they produce to, users pass in their Samza job api logic via StreamTask/AsyncStreamTask/StreamApplication
*/ 

public class TestRunner {
  
  // Static Factory to config & create runner for low level api 
  public static TestRunner of(StreamTask task) {...}
  public static TestRunner of(AsyncStreamTask task) {...}
  public static TestRunner of(StreamApplication app) {...}
  
  // Add/Ovveride any custom configs
  public TestRunner addOverrideConfigs(Map<String,String> configs) {...}
  public TestRunner addOverrideConfigs(String configUri) {...}
  public TestRunner addOverrideConfig(String key, String val){...}
 
  // Set container mode either single container or multi container
  public TestRunner setContainerMode(Mode mode) {...}
  
  // Multithreading configs for users
  public TestRunner setTaskMaxConcurrency(Integer value) {...}
  public TestRunner setTaskCallBackTimeoutMS(Integer value) {...}
  public TestRunner setJobContainerThreadPoolSize(Integer value) {...}
 
  // Configure state for application
  public TestRunner addState(String storeName) {...}  
  
  // Configure an input stream for samza system, that job can consume from
  public TestRunner addInputStream(CollectionStream stream) {...}
  // Configures an output stream for samza system, that job can producer to
  public TestRunner addOutputStream(CollectionStream stream) {...}
  
  // Run the app
  public void run() {...}
}

 

/**
* CollectionStream provides utilities to build an in memory input stream of collections(list, map). It also supports initialization of 
* multiple partitions for an input stream 
*/
 
public class CollectionStream<T> { 
  // Create an empty stream that a Samza job can produce to
  public static <T> CollectionStream<T> empty(String steamId) {...}
  
  // Create a stream of messages from input list with single partition
  public static <T> CollectionStream<T> of(String steamId, Iterable<T> collection){...}
  
  // Create a stream of messages from input list with multiple partition, key of partitions map is partitionId
  public static <T> CollectionStream<T> of(String steamId, Map<Integer,Iterable<T>> partitions){...}
  
}

/**
* EventStream provides utilities to build an in memory input stream of events. It helps mimic run time environment of your job, 
* advancing time for windowing functions  
*/
 
public class EventStream<T> {
  public static abstract class Builder<T> {
    public abstract Builder addElement();
    public abstract Builder addException();
    public abstract Builder advanceTimeTo(long time);
    public abstract EventStream<T> build(); 
 }

 public static <T> Builder<T> builder() {...}
}

/**
* FileStream provides utilities to build a stream of messages from a file on disk
*/
 
public class FileStream<T> {
  public static <T> FileStream<T> of(String fileUri) {...}
}

/**
* Simple Test case using a collection as an input for a low level application. It demonstrates set up and comparison of a test with 
* minimal(eg. here none) configs and it reads an input stream of integers and multiplies each integer with 10
*/
 
// Create a StreamTask
StreamTask myTask = new StreamTask() {
  @Override
  public void process(IncomingMessageEnvelope envelope, MessageCollector collector, TaskCoordinator coordinator) throws Exception {
    Integer obj = (Integer) envelope.getMessage();
    collector.send(new OutgoingMessageEnvelope(new SystemStream("test-samza","output"), obj*10));
  }
};
 
// Initialize and run the test framework
TestRunner
    .of(myTask)
    .setJobContainerThreadPoolSize(4)
    .addInputStream(CollectionStream.of("test-samza.input", {1,2,3,4}))
    .addOutputStream(CollectionStream.empty("test-samza.output"))
    .run();
 
// Assertions on the outputs
StreamAssert.that("test-samza.output").contains({10,30,20,40});

/**
* Simple Test case using a collection as an input for a low level application. It demonstrates set up and comparison of a test with 
* minimal(eg. here none) configs and it reads an input stream of integers and multiplies each integer with 10
*/
 
class MyStreamTaskFactory implements StreamTaskFactory {
    @Override
    public StreamTask createInstance() {
      return (envelope, collector, coordinator) -> {
        return;
      };
    }
  }
}

StreamDescriptor.Input input = StreamDescriptor.<String, String>input("input")
    .withKeySerde(new StringSerde("UTF-8"))
    .withMsgSerde(new StringSerde("UTF-8"));

StreamDescriptor.Output output = StreamDescriptor.<String, String>output("output")
    .withKeySerde(new StringSerde("UTF-8"))
    .withMsgSerde(new StringSerde("UTF-8"));

InMemoryTestSystem testingSystem = InMemoryTestSystem.create("samza-test")
    .addInput(input, {1,2,3,4,5})
    .addOutput("output"/);

StreamTaskApplication app = StreamApplications.createStreamTaskApp(config, new MyStreamTaskFactory());


app
  .addInputs(input)
  .addOutputs(output)
  .runAsTest();
 
// Assertions on the outputs
Assert.assertThat(testingSystem.getStreamState(output), IsIterableContainingInOrder.contains({10,20,30,40,50})));

/**
* Simple Test case using a collection as an input for a low level application in the async mode
*/

// 
public class AsyncRestTask implements AsyncStreamTask, InitableTask, ClosableTask {
  private Client client;
  private WebTarget target; 

  @Override
  public void init(Config config, TaskContext taskContext) throws Exception {
    // Your initialization of web client code goes here
    client = ClientBuilder.newClient();
    target = client.target("http://example.com/resource/").path("hello");
  }

  @Override
  public void processAsync(IncomingMessageEnvelope envelope, MessageCollector collector,
      TaskCoordinator coordinator, final TaskCallback callback) {
    target.request().async().get(new InvocationCallback<Response>() {
      @Override
      public void completed(Response response) {
        Integer obj = (Integer) envelope.getMessage();
        collector.send(new OutgoingMessageEnvelope(new SystemStream("test-samza","output"), obj*10));
        callback.complete();
      }

      @Override
      public void failed(Throwable throwable) {
        System.out.println("Invocation failed.");
        callback.failure(throwable);
      }
    });
  }

  @Override
  public void close() throws Exception {
    client.close();
  }
}
 

// Initialize and run the test framework
TestRunner
    .of(new AsyncRestTask())
	.setTaskCallBackTimeoutMS(200)
	.setTaskMaxConcurrency(4)
	.addInputStream(CollectionStream.of("test-samza.Input", {1,2,3,4}))
	.addOutputStream(CollectionStream.empty("test-samza.output"))
	.run();
 
// Assertions on the outputs
StreamAssert.that("test-samza.output").containsInAnyOrder({10,20,30,40});

/**
* Simple Test case using a collection as an input for a High level application
*/
 
public class MyStreamApplication implements StreamApplication {
  @Override
  public void init(StreamGraph graph, Config config) {
    MessageStream<Integer> pageViews = graph.getInputStream(“test-samza.page-views”);

    pageViews.map(s -> "processed " + s)
             .sendTo(graph.getOutputStream(“test-samza.output”));
 }
}


 
// Initialize and run the test framework
TestRunner
	.of(new MyStreamApplication());
    .addInputStream(CollectionStream.of("test-samza.input", {1,2,3}))
    .addOutputStream(CollectionStream.empty("test-samza.output"))
    .run();
 
// Assertions on the outputs
StreamAssert.that("test-samza.Output").contains({"processed 1", "processed 2", "processed 4"});