# Events.java

    /*
     * Copyright 2009-2010 Rickard Öberg AB
     *
     * 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 org.qi4j.library.eventsourcing.domain.source.helper;

    import java.lang.reflect.Method;
    import java.util.Date;
    import org.qi4j.api.util.Methods;
    import org.qi4j.functional.Function;
    import org.qi4j.functional.Iterables;
    import org.qi4j.functional.Specification;
    import org.qi4j.library.eventsourcing.domain.api.DomainEventValue;
    import org.qi4j.library.eventsourcing.domain.api.UnitOfWorkDomainEventsValue;

    import static org.qi4j.functional.Iterables.map;

    /**
     * Helper methods for working with Iterables of DomainEvents and UnitOfWorkDomainEventsValue.
     */
    public class Events
    {
        public static Iterable<DomainEventValue> events( Iterable<UnitOfWorkDomainEventsValue> transactions )
        {
            return Iterables.flattenIterables( Iterables.map( new Function<UnitOfWorkDomainEventsValue, Iterable<DomainEventValue>>()
            {
                @Override
                public Iterable<DomainEventValue> map( UnitOfWorkDomainEventsValue unitOfWorkDomainEventsValue )
                {
                    return unitOfWorkDomainEventsValue.events().get();
                }
            }, transactions ) );
        }

        public static Iterable<DomainEventValue> events( UnitOfWorkDomainEventsValue... unitOfWorkDomainValues )
        {
            return events( Iterables.iterable( unitOfWorkDomainValues ) );
        }

        // Common specifications
        public static Specification<UnitOfWorkDomainEventsValue> afterDate( final Date afterDate )
        {
            return new Specification<UnitOfWorkDomainEventsValue>()
            {
                @Override
                public boolean satisfiedBy( UnitOfWorkDomainEventsValue eventValue )
                {
                    return eventValue.timestamp().get() > afterDate.getTime();
                }
            };
        }

        public static Specification<UnitOfWorkDomainEventsValue> beforeDate( final Date afterDate )
        {
            return new Specification<UnitOfWorkDomainEventsValue>()
            {
                @Override
                public boolean satisfiedBy( UnitOfWorkDomainEventsValue eventValue )
                {
                    return eventValue.timestamp().get() < afterDate.getTime();
                }
            };
        }

        public static Specification<UnitOfWorkDomainEventsValue> withUsecases( final String... names )
        {
            return new Specification<UnitOfWorkDomainEventsValue>()
            {
                @Override
                public boolean satisfiedBy( UnitOfWorkDomainEventsValue eventValue )
                {
                    for (String name : names)
                    {
                        if (eventValue.usecase().get().equals( name ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<UnitOfWorkDomainEventsValue> byUser( final String... by )
        {
            return new Specification<UnitOfWorkDomainEventsValue>()
            {
                @Override
                public boolean satisfiedBy( UnitOfWorkDomainEventsValue eventValue )
                {
                    for (String user : by)
                    {
                        if (eventValue.user().get().equals( user ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<DomainEventValue> withNames( final Iterable<String> names )
        {
            return new Specification<DomainEventValue>()
            {
                @Override
                public boolean satisfiedBy( DomainEventValue eventValue )
                {
                    for (String name : names)
                    {
                        if (eventValue.name().get().equals( name ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<DomainEventValue> withNames( final String... names )
        {
            return new Specification<DomainEventValue>()
            {
                @Override
                public boolean satisfiedBy( DomainEventValue eventValue )
                {
                    for (String name : names)
                    {
                        if (eventValue.name().get().equals( name ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<DomainEventValue> withNames( final Class eventClass )
        {
            return Events.withNames( map( new Function<Method, String>()
            {
                @Override
                public String map( Method method )
                {
                    return method.getName();
                }
            }, Iterables.toList( Methods.METHODS_OF.map( eventClass ) ) ));
        }

        public static Specification<DomainEventValue> onEntities( final String... entities )
        {
            return new Specification<DomainEventValue>()
            {
                @Override
                public boolean satisfiedBy( DomainEventValue eventValue )
                {
                    for (String entity : entities)
                    {
                        if (eventValue.entityId().get().equals( entity ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<DomainEventValue> onEntityTypes( final String... entityTypes )
        {
            return new Specification<DomainEventValue>()
            {
                @Override
                public boolean satisfiedBy( DomainEventValue eventValue )
                {
                    for (String entityType : entityTypes)
                    {
                        if (eventValue.entityType().get().equals( entityType ))
                            return true;
                    }
                    return false;
                }
            };
        }

        public static Specification<DomainEventValue> paramIs( final String name, final String value )
        {
            return new Specification<DomainEventValue>()
            {
                @Override
                public boolean satisfiedBy( DomainEventValue eventValue )
                {
                    return EventParameters.getParameter( eventValue, name ).equals( value );
                }
            };
        }
    }