/*
 * Copyright 2017 Google LLC
 *
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 * modification, are permitted provided that the following conditions are
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 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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package com.google.api.gax.httpjson;

import static com.google.common.truth.Truth.assertThat;

import com.google.api.client.http.HttpResponseException;
import com.google.api.gax.httpjson.testing.MockHttpService;
import com.google.api.gax.rpc.ApiException;
import com.google.api.gax.rpc.ApiExceptionFactory;
import com.google.api.gax.rpc.StatusCode.Code;
import com.google.api.gax.rpc.testing.FakeStatusCode;
import com.google.protobuf.Field;
import com.google.protobuf.Field.Cardinality;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.threeten.bp.Duration;

@RunWith(JUnit4.class)
public class HttpJsonDirectCallableTest {

  private static final ApiMethodDescriptor<Field, Field> FAKE_METHOD_DESCRIPTOR =
      ApiMethodDescriptor.<Field, Field>newBuilder()
          .setFullMethodName("google.cloud.v1.Fake/FakeMethod")
          .setHttpMethod("POST")
          .setRequestFormatter(
              ProtoMessageRequestFormatter.<Field>newBuilder()
                  .setPath(
                      "/fake/v1/name/{name=bob/*}",
                      request -> {
                        Map<String, String> fields = new HashMap<>();
                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
                        serializer.putPathParam(fields, "name", request.getName());
                        return fields;
                      })
                  .setAdditionalPaths("/fake/v1/name/{name=john/*}")
                  .setQueryParamsExtractor(
                      request -> {
                        Map<String, List<String>> fields = new HashMap<>();
                        ProtoRestSerializer<Field> serializer = ProtoRestSerializer.create();
                        serializer.putQueryParam(fields, "number", request.getNumber());
                        return fields;
                      })
                  .setRequestBodyExtractor(
                      request ->
                          ProtoRestSerializer.create()
                              .toBody("*", request.toBuilder().clearName().build(), false))
                  .build())
          .setResponseParser(
              ProtoMessageResponseParser.<Field>newBuilder()
                  .setDefaultInstance(Field.getDefaultInstance())
                  .build())
          .build();

  private static final MockHttpService MOCK_SERVICE =
      new MockHttpService(Collections.singletonList(FAKE_METHOD_DESCRIPTOR), "google.com:443");

  private final ManagedHttpJsonChannel channel =
      new ManagedHttpJsonInterceptorChannel(
          ManagedHttpJsonChannel.newBuilder()
              .setEndpoint("google.com:443")
              .setExecutor(executorService)
              .setHttpTransport(MOCK_SERVICE)
              .build(),
          new HttpJsonHeaderInterceptor(Collections.singletonMap("header-key", "headerValue")));

  private static ExecutorService executorService;

  @BeforeClass
  public static void initialize() {
    executorService =
        Executors.newFixedThreadPool(
            2,
            r -> {
              Thread t = Executors.defaultThreadFactory().newThread(r);
              t.setDaemon(true);
              return t;
            });
  }

  @AfterClass
  public static void destroy() {
    executorService.shutdownNow();
  }

  @After
  public void tearDown() {
    MOCK_SERVICE.reset();
  }

  @Test
  public void testSuccessfulUnaryResponse() throws ExecutionException, InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    Field request;
    Field expectedResponse;
    request = expectedResponse = createTestMessage(2);

    MOCK_SERVICE.addResponse(expectedResponse);

    Field actualResponse = callable.futureCall(request, callContext).get();

    assertThat(actualResponse).isEqualTo(expectedResponse);
    assertThat(MOCK_SERVICE.getRequestPaths().size()).isEqualTo(1);
    String headerValue = MOCK_SERVICE.getRequestHeaders().get("header-key").iterator().next();
    assertThat(headerValue).isEqualTo("headerValue");
  }

  /**
   * This test is for a Unary Call where server mistakenly sends multiple responses back The
   * expectation for this MOCK_SERVICE is to return what was sent into the request i.e.
   * callable.futureCall(x) -> x
   *
   * <p>For a Unary Call, gax will return only the first (and hopefully only) response back.
   *
   * @throws InterruptedException
   * @throws ExecutionException
   */
  @Test
  public void testSuccessfulMultipleResponsesForUnaryCall()
      throws InterruptedException, ExecutionException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    Field request = createTestMessage(2);
    Field expectedResponse = createTestMessage(2);
    Field otherResponse = createTestMessage(10);
    MOCK_SERVICE.addResponse(expectedResponse);
    MOCK_SERVICE.addResponse(otherResponse);
    MOCK_SERVICE.addResponse(otherResponse);

    Field actualResponse = callable.futureCall(request, callContext).get();
    assertThat(actualResponse).isEqualTo(expectedResponse);
    assertThat(MOCK_SERVICE.getRequestPaths().size()).isEqualTo(1);
    String headerValue = MOCK_SERVICE.getRequestHeaders().get("header-key").iterator().next();
    assertThat(headerValue).isEqualTo("headerValue");
  }

  /**
   * This test is for a Unary Call where server mistakenly sends multiple responses back The
   * expectation for this MOCK_SERVICE is to return what was sent into the request i.e.
   * callable.futureCall(x) -> x
   *
   * <p>For a Unary Call, gax will return only the first (and hopefully only) response back.
   *
   * @throws InterruptedException
   * @throws ExecutionException
   */
  @Test
  public void testErrorMultipleResponsesForUnaryCall()
      throws InterruptedException, ExecutionException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    Field request = createTestMessage(2);
    Field expectedResponse = createTestMessage(2);
    Field randomResponse1 = createTestMessage(10);
    Field randomResponse2 = createTestMessage(3);
    MOCK_SERVICE.addResponse(randomResponse1);
    MOCK_SERVICE.addResponse(expectedResponse);
    MOCK_SERVICE.addResponse(randomResponse2);

    Field actualResponse = callable.futureCall(request, callContext).get();
    // Gax returns the first response for Unary Call
    assertThat(actualResponse).isEqualTo(randomResponse1);
    assertThat(actualResponse).isNotEqualTo(expectedResponse);
    assertThat(MOCK_SERVICE.getRequestPaths().size()).isEqualTo(1);
    String headerValue = MOCK_SERVICE.getRequestHeaders().get("header-key").iterator().next();
    assertThat(headerValue).isEqualTo("headerValue");
  }

  /**
   * The expectation for gax is that an exception from the server will return an exception response
   *
   * @throws InterruptedException
   */
  @Test
  public void testErrorUnaryResponse() throws InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    ApiException exception =
        ApiExceptionFactory.createException(
            new Exception(), FakeStatusCode.of(Code.NOT_FOUND), false);
    MOCK_SERVICE.addException(exception);

    try {
      callable.futureCall(createTestMessage(2), callContext).get();
      Assert.fail("No exception raised");
    } catch (ExecutionException e) {
      HttpResponseException respExp = (HttpResponseException) e.getCause();
      assertThat(respExp.getStatusCode()).isEqualTo(400);
      assertThat(respExp.getContent()).isEqualTo(exception.toString());
    }
  }

  /**
   * This test is for a Unary Call where server sends back a null value but successful status code
   * Gax expects the response back to be parse-able into JSON but the null value is not valid. This
   * will throw an Exception for a successful response but invalid content
   *
   * @throws InterruptedException
   */
  @Test
  public void testErrorNullContentSuccessfulResponse() throws InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    MOCK_SERVICE.addNullResponse();

    try {
      callable.futureCall(createTestMessage(2), callContext).get();
      Assert.fail("No exception raised");
    } catch (ExecutionException e) {
      HttpJsonStatusRuntimeException respExp = (HttpJsonStatusRuntimeException) e.getCause();
      assertThat(respExp.getStatusCode()).isEqualTo(200);
      assertThat(respExp.getCause().getMessage())
          .isEqualTo("Both response message and response exception were null");
    }
  }

  /**
   * The expectation for a non-2xx from the server is an exception response regardless of the
   * content sent back
   *
   * @throws InterruptedException
   */
  @Test
  public void testErrorNullContentFailedResponse() throws InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));
    MOCK_SERVICE.addNullResponse(400);

    try {
      callable.futureCall(createTestMessage(2), callContext).get();
      Assert.fail("No exception raised");
    } catch (ExecutionException e) {
      HttpResponseException respExp = (HttpResponseException) e.getCause();
      assertThat(respExp.getStatusCode()).isEqualTo(400);
      assertThat(respExp.getContent()).isNull();
    }
  }

  /**
   * Expectation is that an Exception is returned even on a non-2xx status code
   *
   * @throws InterruptedException
   */
  @Test
  public void testErrorNon2xxOr4xxResponse() throws InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault()
            .withChannel(channel)
            .withTimeout(Duration.ofSeconds(30));

    ApiException exception =
        ApiExceptionFactory.createException(
            new Exception(), FakeStatusCode.of(Code.INTERNAL), false);
    MOCK_SERVICE.addException(500, exception);

    try {
      callable.futureCall(createTestMessage(2), callContext).get();
      Assert.fail("No exception raised");
    } catch (ExecutionException e) {
      HttpResponseException respExp = (HttpResponseException) e.getCause();
      assertThat(respExp.getStatusCode()).isEqualTo(500);
      assertThat(respExp.getContent()).isEqualTo(exception.toString());
    }
  }

  /**
   * Expectation is that an RPC that exceeds the Timeout value set will receive a DEADLINE_EXCEEDED
   * response back. In this test, the call has a timeout value that is smaller than the time it
   * takes for the mock service to return a response.
   *
   * @throws InterruptedException
   */
  @Test
  public void testDeadlineExceededResponse() throws InterruptedException {
    HttpJsonDirectCallable<Field, Field> callable =
        new HttpJsonDirectCallable<>(FAKE_METHOD_DESCRIPTOR);

    HttpJsonCallContext callContext =
        HttpJsonCallContext.createDefault().withChannel(channel).withTimeout(Duration.ofSeconds(3));

    Field response = createTestMessage(10);
    MOCK_SERVICE.addResponse(response, java.time.Duration.ofSeconds(5));

    try {
      callable.futureCall(createTestMessage(10), callContext).get();
      Assert.fail("No exception raised");
    } catch (ExecutionException e) {
      HttpJsonStatusRuntimeException respExp = (HttpJsonStatusRuntimeException) e.getCause();
      assertThat(respExp.getStatusCode()).isEqualTo(504);
      assertThat(respExp.getMessage()).isEqualTo("Deadline exceeded");
    }
  }

  private Field createTestMessage(int number) {
    return Field.newBuilder() // "echo" service
        .setName("john/imTheBestField")
        .setNumber(number)
        .setCardinality(Cardinality.CARDINALITY_OPTIONAL)
        .setDefaultValue("blah")
        .build();
  }
}