package com.atlassian.plugin.manager;
   
   import com.atlassian.plugin.MockModuleDescriptor;
   import com.atlassian.plugin.ModuleDescriptor;
   import com.atlassian.plugin.Plugin;
   import com.atlassian.plugin.PluginAccessor;
   import com.atlassian.plugin.PluginController;
   import com.atlassian.plugin.event.PluginEventManager;
   import com.atlassian.plugin.event.events.PluginDisabledEvent;
  import com.atlassian.plugin.event.events.PluginEnabledEvent;
  import com.atlassian.plugin.event.events.PluginModuleDisabledEvent;
  import com.atlassian.plugin.event.events.PluginModuleEnabledEvent;
  import com.atlassian.plugin.event.impl.DefaultPluginEventManager;
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.Iterators;
  import com.google.common.collect.Lists;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.mockito.Mock;
  import org.mockito.junit.MockitoJUnit;
  import org.mockito.junit.MockitoRule;
  
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  
  import static com.google.common.collect.Lists.newArrayList;
  import static java.util.Collections.singletonList;
  import static org.hamcrest.Matchers.contains;
  import static org.hamcrest.Matchers.containsInAnyOrder;
  import static org.hamcrest.Matchers.empty;
  import static org.hamcrest.Matchers.sameInstance;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertSame;
  import static org.junit.Assert.assertThat;
  import static org.mockito.ArgumentMatchers.any;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.never;
  import static org.mockito.Mockito.times;
  import static org.mockito.Mockito.verify;
  import static org.mockito.Mockito.when;
  
  /**
   * Mock-based unit tests of {@link EnabledModuleCachingPluginAccessor}.
   *
   * @see TestDefaultPluginManagerWithCachingPluginAccessor for integration test with {@link DefaultPluginManager}.
   */
  public class TestEnabledModuleCachingPluginAccessor {
      private PluginEventManager pluginEventManager;
  
      @Rule
      public final MockitoRule mockitoRule = MockitoJUnit.rule();
  
      @Mock
      private PluginAccessor delegate;
      @Mock
      private PluginController pluginController;
      private PluginAccessor cachingPluginAccessor;
  
      @Before
      public void setUp() throws Exception {
          pluginEventManager = new DefaultPluginEventManager();
          cachingPluginAccessor = new EnabledModuleCachingPluginAccessor(delegate, pluginEventManager, pluginController);
      }
  
      @Test
      public void testGetEnabledModuleDescriptorsByClassDelegateShouldCalculateAtMostOnce() {
          // call the cached method multiple times.
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
          // should have been called only once
          verify(delegate, times(1)).getEnabledModuleDescriptorsByClass(Descriptor.class);
  
          // broadcast new module and then call again multiple times
          pluginEventManager.broadcast(new PluginModuleEnabledEvent(new Descriptor(new Module())));
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
  
          // should have been called only once more (because the cache was cleared and re-loaded following enabled event)
          verify(delegate, times(2)).getEnabledModuleDescriptorsByClass(Descriptor.class);
      }
  
      @Test
      public void testGetEnabledModuleDescriptorsByClassFlushCacheAfterAnyPluginDisable() {
          // call the cached method - populates cache
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
          verify(delegate, times(1)).getEnabledModuleDescriptorsByClass(Descriptor.class);
  
          pluginEventManager.broadcast(new PluginDisabledEvent(mock(Plugin.class)));
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
          cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
  
          // Called again (but only once more) following cache flush
          verify(delegate, times(2)).getEnabledModuleDescriptorsByClass(Descriptor.class);
      }
  
      @Test
     public void testGetEnabledModuleDescriptorsByClassFlushCacheAfterAnyPluginEnable() {
         // call the cached method - populates cache
         cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
         verify(delegate, times(1)).getEnabledModuleDescriptorsByClass(Descriptor.class);
 
         pluginEventManager.broadcast(new PluginEnabledEvent(mock(Plugin.class)));
         cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
         cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
 
         // Called again (but only once more) following cache flush
         verify(delegate, times(2)).getEnabledModuleDescriptorsByClass(Descriptor.class);
     }
 
     @Test
     public void testGetEnabledModuleDescriptorsByClassChildAndParentClassBeingTrackedSeparately() {
         final ChildDescriptor<ChildModule> childDescriptor = new ChildDescriptor<>(new ChildModule());
         final ParentDescriptor<ParentModule> parentDescriptor = new ParentDescriptor<>(new ParentModule());
 
         when(delegate.getEnabledModuleDescriptorsByClass(ChildDescriptor.class))
                 .thenReturn(Collections.<ChildDescriptor>singletonList(childDescriptor));
         when(delegate.getEnabledModuleDescriptorsByClass(ParentDescriptor.class))
                 .thenReturn(Lists.<ParentDescriptor>newArrayList(parentDescriptor, childDescriptor));
 
         final List<ChildDescriptor> result = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ChildDescriptor.class);
         assertEquals(1, result.size());
         assertSame(childDescriptor, result.get(0));
 
         final List<ParentDescriptor> result2 = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ParentDescriptor.class);
         // (gave up on trying to get generics to work with 'contains/containsInAnyOrder')
         assertEquals(2, result2.size());
         assertEquals(parentDescriptor, result2.get(0));
         assertEquals(childDescriptor, result2.get(1));
     }
 
     @Test
     public void testGetEnabledModuleDescriptorsByClassFindsLateChild() {
         final ChildDescriptor childDescriptor = new ChildDescriptor<>(new ChildModule());
         final ParentDescriptor parentDescriptor = new ParentDescriptor<>(new ParentModule());
 
         when(delegate.getEnabledModuleDescriptorsByClass(ChildDescriptor.class)).thenReturn(ImmutableList.of());
         when(delegate.getEnabledModuleDescriptorsByClass(ParentDescriptor.class)).thenReturn(ImmutableList.of(parentDescriptor));
 
         final List<ChildDescriptor> childBefore = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ChildDescriptor.class);
         final List<ParentDescriptor> parentBefore = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ParentDescriptor.class);
 
         assertThat(childBefore, empty());
         assertThat(parentBefore, contains(parentDescriptor));
 
         // Now enable child
 
         when(delegate.getEnabledModuleDescriptorsByClass(ChildDescriptor.class)).thenReturn(ImmutableList.of(childDescriptor));
         when(delegate.getEnabledModuleDescriptorsByClass(ParentDescriptor.class)).
                 thenReturn(ImmutableList.of(parentDescriptor, childDescriptor));
 
         pluginEventManager.broadcast(new PluginModuleEnabledEvent(childDescriptor));
 
         final List<ChildDescriptor> childAfter = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ChildDescriptor.class);
         final List<ParentDescriptor> parentAfter = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(ParentDescriptor.class);
 
         assertThat(childAfter, contains(childDescriptor));
         assertThat(parentAfter, contains(parentDescriptor, childDescriptor));
     }
 
     @Test
     public void testGetEnabledModuleDescriptorsByClassWhenModuleEnabledBeforeCacheAccessed() {
         final Descriptor descriptor = new Descriptor(new Module());
 
         // Mock for cache loader as if module already enabled
         when(delegate.getEnabledModuleDescriptorsByClass(Descriptor.class)).thenReturn(singletonList(descriptor));
 
         // Cache loader should see the module
         List<Descriptor> result = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
         assertThat(result, contains(descriptor));
     }
 
     @Test
     public void testGetEnabledModuleDescriptorsByClassWhenModuleEnabledAfterCacheAccessed() {
         final Descriptor descriptor = new Descriptor(new Module());
 
         // Mock for cache loader as if module initially disabled
         when(delegate.getEnabledModuleDescriptorsByClass(Descriptor.class)).thenReturn(Collections.<Descriptor>emptyList());
 
         // Cache loader
         List<Descriptor> result = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
         assertThat(result, empty());
 
         // Now gets enabled - should see the event and reload the cache
         when(delegate.getEnabledModuleDescriptorsByClass(Descriptor.class)).thenReturn(singletonList(descriptor));
         pluginEventManager.broadcast(new PluginModuleEnabledEvent(descriptor));
 
         result = cachingPluginAccessor.getEnabledModuleDescriptorsByClass(Descriptor.class);
         assertThat(result, contains(descriptor));
     }
 
     @Test
     public void testGetEnabledModulesByClassDelegateShouldCalculateAtMostOnce() {
         // call the cached method multiple times.
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache loading of ByModuleClassCacheLoader works via a predicate across all plugins' modules,
         // not by calling the delegate: see EnabledModuleCachingPluginAccessor.getEnabledModuleDescriptorsByModuleClass()
         verify(delegate, times(1)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
 
         // broadcast new module and then call again.
         pluginEventManager.broadcast(new PluginModuleEnabledEvent(new Descriptor(new Module())));
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Only one more call through to delegate (due to the enabled event clearing the cache entry)
         verify(delegate, times(2)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
     }
 
     @Test
     public void testGetEnabledModulesByClassFlushCacheAfterAnyPluginEnable() {
         // call the cached method - populates cache
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache loading of ByModuleClassCacheLoader works via a predicate across all plugins' modules,
         // not by calling the delegate: see EnabledModuleCachingPluginAccessor.getEnabledModuleDescriptorsByModuleClass()
         verify(delegate, times(1)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
 
         pluginEventManager.broadcast(new PluginEnabledEvent(mock(Plugin.class)));
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache has been cleared, now gets loaded again
         verify(delegate, times(2)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
     }
 
     @Test
     public void testGetEnabledModulesByClassFlushCacheAfterAnyPluginDisable() {
         // call the cached method - populates cache
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache loading of ByModuleClassCacheLoader works via a predicate across all plugins' modules,
         // not by calling the delegate: see EnabledModuleCachingPluginAccessor.getEnabledModuleDescriptorsByModuleClass()
         verify(delegate, times(1)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
 
         pluginEventManager.broadcast(new PluginDisabledEvent(mock(Plugin.class)));
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache has been cleared, now gets loaded again
         verify(delegate, times(2)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
     }
 
     @Test
     public void testGetEnabledModulesByClassFlushCacheAfterAnyPluginModuleDisable() {
         Descriptor descriptor = new Descriptor(new Module());
 
         // call the cached method - populates cache
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache loading of ByModuleClassCacheLoader works via a predicate across all plugins' modules,
         // not by calling the delegate: see EnabledModuleCachingPluginAccessor.getEnabledModuleDescriptorsByModuleClass()
         verify(delegate, times(1)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
 
         pluginEventManager.broadcast(new PluginModuleDisabledEvent(descriptor, false));
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         cachingPluginAccessor.getEnabledModulesByClass(Module.class);
 
         // Cache has been cleared, now gets loaded again
         verify(delegate, times(2)).getEnabledPlugins();
         verify(delegate, never()).getEnabledModulesByClass(any(Class.class));
     }
 
     @Test
     public void testGetEnabledModulesByClassChildAndParentClassBeingTrackedSeparately() {
         final ChildModule childModule = new ChildModule();
         final ChildDescriptor<ChildModule> childDescriptor = new ChildDescriptor<>(childModule);
         childDescriptor.enabled();
         final ParentModule parentModule = new ParentModule();
         final ParentDescriptor<ParentModule> parentDescriptor = new ParentDescriptor<>(parentModule);
         parentDescriptor.enabled();
 
         // Mock for cache loader
         final Plugin plugin = mock(Plugin.class);
         when(delegate.getEnabledPlugins()).thenReturn(newArrayList(plugin));
         when(plugin.getModuleDescriptors()).thenReturn(Lists.<ModuleDescriptor<?>>newArrayList(parentDescriptor, childDescriptor));
 
         assertThat(cachingPluginAccessor.getEnabledModulesByClass(ChildModule.class),
                 contains(childModule));
         assertThat(cachingPluginAccessor.getEnabledModulesByClass(ParentModule.class),
                 containsInAnyOrder(parentModule, childModule));
     }
 
     @Test
     public void testGetEnabledModulesByClassWhenModuleEnabledBeforeCacheAccessed() {
         final Module module = new Module();
         final Descriptor descriptor = new Descriptor(module);
         descriptor.enabled();
 
         // Mock for cache loader - module already enabled
         final Plugin plugin = mock(Plugin.class);
         when(delegate.getEnabledPlugins()).thenReturn(newArrayList(plugin));
         when(plugin.getModuleDescriptors()).thenReturn(Collections.<ModuleDescriptor<?>>singletonList(descriptor));
 
         // Cache loader should see the module
         List<Module> result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertThat(result, contains(module));
     }
 
     @Test
     public void testGetEnabledModulesByClassWhenModuleEnabledAfterCacheAccessed() {
         final Module module = new Module();
         final Descriptor descriptor = new Descriptor(module);
         assertFalse(descriptor.isEnabled());
 
         // Mock for cache loader - module returned, but initially disabled
         final Plugin plugin = mock(Plugin.class);
         when(delegate.getEnabledPlugins()).thenReturn(newArrayList(plugin));
         when(plugin.getModuleDescriptors()).thenReturn(Collections.<ModuleDescriptor<?>>singletonList(descriptor));
 
         // Cache loader
         List<Module> result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertThat(result, empty());
 
         // Now gets enabled - tracker should see the event and return the module
         descriptor.enabled();
         pluginEventManager.broadcast(new PluginModuleEnabledEvent(descriptor));
 
         result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertThat(result, contains(module));
     }
 
     @Test
     public void testGetEnabledModulesByClassDoesNotCacheModulesOnlyDescriptors() {
         // Different module each time 'getModule' is called
         final Module module1 = mock(Module.class, "module1");
         final Module module2 = mock(Module.class, "module2");
         final Module module3 = mock(Module.class, "module3");
         final MockModuleDescriptor<Module> descriptor = new MockModuleDescriptor<Module>(mock(Plugin.class), "descriptor", module1) {
             private Iterator<Module> modules = Iterators.forArray(module1, module2, module3);
 
             @Override
             public Module getModule() {
                 return modules.next();
             }
         };
         descriptor.enabled();
 
         // Mock for cache loader - module already enabled
         final Plugin plugin = mock(Plugin.class);
         when(delegate.getEnabledPlugins()).thenReturn(newArrayList(plugin));
         when(plugin.getModuleDescriptors()).thenReturn(Collections.<ModuleDescriptor<?>>singletonList(descriptor));
 
         List<Module> result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertEquals(1, result.size());
         assertThat(result.get(0), sameInstance(module1));
 
         // Module is re-retrieved from descriptor every time
         result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertEquals(1, result.size());
         assertThat(result.get(0), sameInstance(module2));
 
         result = cachingPluginAccessor.getEnabledModulesByClass(Module.class);
         assertEquals(1, result.size());
         assertThat(result.get(0), sameInstance(module3));
     }
 
     class Module {
     }
 
     class ParentModule {
     }
 
     class ChildModule extends ParentModule {
     }
 
     class Descriptor extends MockModuleDescriptor<Module> {
         public Descriptor(Module module) {
             super(mock(Plugin.class), "descriptorKey", module);
         }
     }
 
     class ParentDescriptor<M extends ParentModule> extends MockModuleDescriptor<M> {
         public ParentDescriptor(String key, M module) {
             super(mock(Plugin.class), key, module);
         }
 
         public ParentDescriptor(M module) {
             this("parentDescriptorKey", module);
         }
     }
 
     class ChildDescriptor<M extends ChildModule> extends ParentDescriptor<M> {
         public ChildDescriptor(M module) {
             super("childDescriptorKey", module);
         }
     }
 }