# HasUoWFilesLifecycle.java

    /*
     * Copyright 2011 Paul Merlin.
     *
     * 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.uowfile.plural;

    import java.io.File;
    import java.util.ArrayList;
    import java.util.List;
    import org.qi4j.api.entity.Lifecycle;
    import org.qi4j.api.entity.LifecycleException;
    import org.qi4j.api.injection.scope.This;
    import org.qi4j.api.mixin.Mixins;

    @Mixins( HasUoWFilesLifecycle.Mixin.class )
    public interface HasUoWFilesLifecycle<T extends Enum<T>>
        extends HasUoWFiles<T>, Lifecycle
    {
        public class Mixin
            implements Lifecycle
        {
            @This
            private HasUoWFiles<?> hasUoWFiles;

            @Override
            public void create()
                throws LifecycleException
            {
                // NOOP
            }

            @Override
            public void remove()
                throws LifecycleException
            {
                // We use the managed files so that if the UoW gets discarded the files will be restored
                List<File> errors = new ArrayList<>();
                for( File eachFile : hasUoWFiles.managedFiles() )
                {
                    if( eachFile.exists() )
                    {
                        if( !eachFile.delete() )
                        {
                            errors.add( eachFile );
                        }
                    }
                }
                if( !errors.isEmpty() )
                {
                    throw new LifecycleException( "Unable to delete existing files: " + errors );
                }
            }
        }

    }