# IterableQuery.java

    /*
     * Licensed to the Apache Software Foundation (ASF) under one
     * or more contributor license agreements.  See the NOTICE file
     * distributed with this work for additional information
     * regarding copyright ownership.  The ASF licenses this file
     * to you 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.api.dataset.iterable;

    import java.util.HashMap;
    import java.util.Map;
    import org.qi4j.api.dataset.Query;
    import org.qi4j.api.property.Property;
    import org.qi4j.api.query.QueryException;
    import org.qi4j.functional.Iterables;
    import org.qi4j.functional.Specification;
    import org.qi4j.functional.Visitor;

    /**
     * TODO
     */
    public class IterableQuery<T> implements Query<T>
    {
        private Iterable<T> iterable;
        private int skip;
        private int limit;
        private Map<String, Object> variables = new HashMap<String, Object>();

        public IterableQuery( Iterable<T> iterable )
        {
            this.iterable = iterable;
        }

        @Override
        public Query filter( Specification<T> filter )
        {
            iterable = Iterables.filter( filter, iterable );

            return this;
        }

        @Override
        public Query orderBy( Property<?> property, Order order )
        {
            return this;
        }

        @Override
        public Query skip( int skipNrOfResults )
        {
            this.skip = skipNrOfResults;

            return this;
        }

        @Override
        public Query limit( int maxNrOfResults )
        {
            this.limit = maxNrOfResults;
            return this;
        }

        @Override
        public Query<T> setVariable( String name, Object value )
        {
            variables.put( name, value );
            return this;
        }

        @Override
        public Object getVariable( String name )
        {
            return variables.get( name );
        }

        @Override
        public long count()
        {
            return Iterables.count( Iterables.limit( limit, Iterables.skip( skip, iterable ) ) );
        }

        @Override
        public T first()
        {
            return Iterables.first( Iterables.limit( limit, Iterables.skip( skip, iterable ) ) );
        }

        @Override
        public T single()
            throws QueryException
        {
            return Iterables.single( Iterables.limit( limit, Iterables.skip( skip, iterable ) ) );
        }

        @Override
        public <ThrowableType extends Throwable> boolean execute( Visitor<T, ThrowableType> resultVisitor )
            throws ThrowableType
        {
            for( T t : toIterable() )
            {
                if( !resultVisitor.visit( t ) )
                {
                    return false;
                }
            }

            return true;
        }

        @Override
        public Iterable<T> toIterable()
            throws QueryException
        {
            return Iterables.limit( limit, Iterables.skip( skip, iterable ) );
        }
    }