/*
 * Copyright 2014 The gRPC Authors
 *
 * 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.
 */

package io.grpc.util;

import static com.google.common.collect.Iterables.getOnlyElement;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertTrue;

import io.grpc.BindableService;
import io.grpc.MethodDescriptor;
import io.grpc.MethodDescriptor.Marshaller;
import io.grpc.MethodDescriptor.MethodType;
import io.grpc.ServerCallHandler;
import io.grpc.ServerMethodDefinition;
import io.grpc.ServerServiceDefinition;
import io.grpc.ServiceDescriptor;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;

/** Unit tests for {@link MutableHandlerRegistry}. */
@RunWith(JUnit4.class)
public class MutableHandlerRegistryTest {
  @Rule public final MockitoRule mocks = MockitoJUnit.rule();

  private MutableHandlerRegistry registry = new MutableHandlerRegistry();

  @Mock
  private Marshaller<String> requestMarshaller;

  @Mock
  private Marshaller<Integer> responseMarshaller;

  @Mock
  private ServerCallHandler<String, Integer> flowHandler;

  @Mock
  private ServerCallHandler<String, Integer> coupleHandler;

  @Mock
  private ServerCallHandler<String, Integer> fewHandler;

  private ServerServiceDefinition basicServiceDefinition;
  private ServerServiceDefinition multiServiceDefinition;

  @SuppressWarnings("rawtypes")
  private ServerMethodDefinition flowMethodDefinition;

  @Before
  public void setUp() throws Exception {
    MethodDescriptor<String, Integer> flowMethod = MethodDescriptor.<String, Integer>newBuilder()
        .setType(MethodType.UNKNOWN)
        .setFullMethodName("basic/flow")
        .setRequestMarshaller(requestMarshaller)
        .setResponseMarshaller(responseMarshaller)
        .build();
    basicServiceDefinition = ServerServiceDefinition.builder(
        new ServiceDescriptor("basic", flowMethod))
        .addMethod(flowMethod, flowHandler)
        .build();

    MethodDescriptor<String, Integer> coupleMethod =
        flowMethod.toBuilder().setFullMethodName("multi/couple").build();
    MethodDescriptor<String, Integer> fewMethod =
        flowMethod.toBuilder().setFullMethodName("multi/few").build();
    multiServiceDefinition = ServerServiceDefinition.builder(
        new ServiceDescriptor("multi", coupleMethod, fewMethod))
        .addMethod(coupleMethod, coupleHandler)
        .addMethod(fewMethod, fewHandler)
        .build();

    flowMethodDefinition = getOnlyElement(basicServiceDefinition.getMethods());
  }

  /** Final checks for all tests. */
  @After
  public void makeSureMocksUnused() {
    Mockito.verifyNoInteractions(requestMarshaller);
    Mockito.verifyNoInteractions(responseMarshaller);
    Mockito.verifyNoMoreInteractions(flowHandler);
    Mockito.verifyNoMoreInteractions(coupleHandler);
    Mockito.verifyNoMoreInteractions(fewHandler);
  }

  @Test
  public void simpleLookup() {
    assertNull(registry.addService(basicServiceDefinition));
    ServerMethodDefinition<?, ?> method = registry.lookupMethod("basic/flow");
    assertSame(flowMethodDefinition, method);

    assertNull(registry.lookupMethod("/basic/flow"));
    assertNull(registry.lookupMethod("basic/basic"));
    assertNull(registry.lookupMethod("flow/flow"));
    assertNull(registry.lookupMethod("completely/random"));
  }

  @Test
  public void simpleLookupWithBindable() {
    BindableService bindableService =
        new BindableService() {
          @Override
          public ServerServiceDefinition bindService() {
            return basicServiceDefinition;
          }
        };

    assertNull(registry.addService(bindableService));

    ServerMethodDefinition<?, ?> method = registry.lookupMethod("basic/flow");
    assertSame(flowMethodDefinition, method);
  }

  @Test
  public void multiServiceLookup() {
    assertNull(registry.addService(basicServiceDefinition));
    assertNull(registry.addService(multiServiceDefinition));

    ServerCallHandler<?, ?> handler = registry.lookupMethod("basic/flow").getServerCallHandler();
    assertSame(flowHandler, handler);
    handler = registry.lookupMethod("multi/couple").getServerCallHandler();
    assertSame(coupleHandler, handler);
    handler = registry.lookupMethod("multi/few").getServerCallHandler();
    assertSame(fewHandler, handler);
  }

  @Test
  public void removeAndLookup() {
    assertNull(registry.addService(multiServiceDefinition));
    assertNotNull(registry.lookupMethod("multi/couple"));
    assertNotNull(registry.lookupMethod("multi/few"));
    assertTrue(registry.removeService(multiServiceDefinition));
    assertNull(registry.lookupMethod("multi/couple"));
    assertNull(registry.lookupMethod("multi/few"));
  }

  @Test
  public void replaceAndLookup() {
    assertNull(registry.addService(basicServiceDefinition));
    assertNotNull(registry.lookupMethod("basic/flow"));
    MethodDescriptor<String, Integer> anotherMethod = MethodDescriptor.<String, Integer>newBuilder()
        .setType(MethodType.UNKNOWN)
        .setFullMethodName("basic/another")
        .setRequestMarshaller(requestMarshaller)
        .setResponseMarshaller(responseMarshaller)
        .build();
    ServerServiceDefinition replaceServiceDefinition = ServerServiceDefinition.builder(
        new ServiceDescriptor("basic", anotherMethod))
        .addMethod(anotherMethod, flowHandler).build();
    ServerMethodDefinition<?, ?> anotherMethodDefinition =
        replaceServiceDefinition.getMethod("basic/another");
    assertSame(basicServiceDefinition, registry.addService(replaceServiceDefinition));

    assertNull(registry.lookupMethod("basic/flow"));
    ServerMethodDefinition<?, ?> method = registry.lookupMethod("basic/another");
    assertSame(anotherMethodDefinition, method);
  }

  @Test
  public void removeSameSucceeds() {
    assertNull(registry.addService(basicServiceDefinition));
    assertTrue(registry.removeService(basicServiceDefinition));
  }

  @Test
  public void doubleRemoveFails() {
    assertNull(registry.addService(basicServiceDefinition));
    assertTrue(registry.removeService(basicServiceDefinition));
    assertFalse(registry.removeService(basicServiceDefinition));
  }

  @Test
  public void removeMissingFails() {
    assertFalse(registry.removeService(basicServiceDefinition));
  }

  @Test
  public void removeMissingNameConflictFails() {
    assertNull(registry.addService(basicServiceDefinition));
    assertFalse(registry.removeService(ServerServiceDefinition.builder(
        new ServiceDescriptor("basic")).build()));
  }

  @Test
  public void initialAddReturnsNull() {
    assertNull(registry.addService(basicServiceDefinition));
    assertNull(registry.addService(multiServiceDefinition));
  }

  @Test
  public void missingMethodLookupReturnsNull() {
    assertNull(registry.lookupMethod("bad"));
  }

  @Test
  public void addAfterRemoveReturnsNull() {
    assertNull(registry.addService(basicServiceDefinition));
    assertTrue(registry.removeService(basicServiceDefinition));
    assertNull(registry.addService(basicServiceDefinition));
  }

  @Test
  public void addReturnsPrevious() {
    assertNull(registry.addService(basicServiceDefinition));
    assertSame(basicServiceDefinition,
        registry.addService(ServerServiceDefinition.builder(
            new ServiceDescriptor("basic")).build()));
  }
}