package com.atlassian.event.internal;
   
   import com.atlassian.event.spi.ListenerInvoker;
   import com.google.common.collect.Sets;
   
   import java.lang.reflect.InvocationTargetException;
   import java.lang.reflect.Method;
   import java.util.Optional;
   import java.util.Set;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  /**
   * A listener invoker that knows how to call a given single parameter method on a given object.
   *
   * @since 2.0
   */
  final class SingleParameterMethodListenerInvoker implements ListenerInvoker {
      private final Method method;
      private final Object listener;
      private final Optional<String> scope;
  
  
      public SingleParameterMethodListenerInvoker(Object listener, Method method) {
          this(listener, method, Optional.empty());
      }
  
      public SingleParameterMethodListenerInvoker(Object listener, Method method, Optional<String> scope) {
          this.listener = checkNotNull(listener);
          this.method = checkNotNull(method);
          this.scope = checkNotNull(scope);
      }
  
      public Set<Class<?>> getSupportedEventTypes() {
          return Sets.newHashSet(method.getParameterTypes());
      }
  
      public void invoke(Object event) {
          try {
              method.invoke(listener, event);
          } catch (IllegalAccessException e) {
              throw new RuntimeException("Listener: " + listener.getClass().getName()
                      + " event: " + event.getClass().getName(), e);
          } catch (InvocationTargetException e) {
              if (e.getCause() == null) {
                  throw new RuntimeException("Listener: " + listener.getClass().getName()
                          + " event: " + event.getClass().getName(), e);
              } else if (e.getCause().getMessage() == null) {
                  throw new RuntimeException("Listener: " + listener.getClass().getName()
                          + " event: " + event.getClass().getName(), e.getCause());
              } else {
                  throw new RuntimeException(e.getCause().getMessage()
                          + ". Listener: " + listener.getClass().getName()
                          + " event: " + event.getClass().getName(),
                          e.getCause());
              }
          }
      }
  
      public boolean supportAsynchronousEvents() {
          return true;
      }
  
      @Override
      public Optional<String> getScope()
      {
          return scope;
      }
  
      @Override
      public String toString() {
          return "SingleParameterMethodListenerInvoker{method=" + method + ", listener=" + paranoidToString(listener) + '}';
      }
  
      /**
       * Calls the object's toString() method. If an exception is thrown from the object's toString() method then this
       * method falls back to the "identity" toString() (as per JVM defaults).
       *
       * @param object an Object
       * @return a human-readable String representation of the object
       */
      private String paranoidToString(Object object) {
          try {
              return String.valueOf(object);
          } catch (RuntimeException e) {
              return object.getClass().getName() + '@' + Integer.toHexString(System.identityHashCode(object));
          }
      }
  }