/*
 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package java.util.stream;

import java.util.Spliterator;
import java.util.function.IntFunction;

/**
 * The base type for a stateful test operation.
 */
interface StatefulTestOp<E> extends IntermediateTestOp<E, E> {

    @SuppressWarnings({"rawtypes", "unchecked"})
    public static<T> AbstractPipeline chain(AbstractPipeline upstream,
                                            StatefulTestOp op) {
        switch (op.outputShape()) {
            case REFERENCE:
                return new ReferencePipeline.StatefulOp<Object, T>(upstream, op.inputShape(), op.opGetFlags()) {
                    @Override
                    public Sink opWrapSink(int flags, Sink sink) {
                        return op.opWrapSink(flags, isParallel(), sink);
                    }

                    @Override
                    public <P_IN> Spliterator<T> opEvaluateParallelLazy(PipelineHelper<T> helper,
                                                                 Spliterator<P_IN> spliterator) {
                        return op.opEvaluateParallelLazy(helper, spliterator);
                    }

                    @Override
                    public <P_IN> Node<T> opEvaluateParallel(PipelineHelper<T> helper,
                                                      Spliterator<P_IN> spliterator,
                                                      IntFunction<T[]> generator) {
                        return op.opEvaluateParallel(helper, spliterator, generator);
                    }
                };
            case INT_VALUE:
                return new IntPipeline.StatefulOp<Object>(upstream, op.inputShape(), op.opGetFlags()) {
                    @Override
                    public Sink opWrapSink(int flags, Sink sink) {
                        return op.opWrapSink(flags, isParallel(), sink);
                    }

                    @Override
                    public <P_IN> Spliterator<Integer> opEvaluateParallelLazy(PipelineHelper<Integer> helper,
                                                                 Spliterator<P_IN> spliterator) {
                        return op.opEvaluateParallelLazy(helper, spliterator);
                    }

                    @Override
                    public <P_IN> Node<Integer> opEvaluateParallel(PipelineHelper<Integer> helper,
                                                            Spliterator<P_IN> spliterator,
                                                            IntFunction<Integer[]> generator) {
                        return (Node<Integer>) op.opEvaluateParallel(helper, spliterator, generator);
                    }
                };
            case LONG_VALUE:
                return new LongPipeline.StatefulOp<Object>(upstream, op.inputShape(), op.opGetFlags()) {
                    @Override
                    public Sink opWrapSink(int flags, Sink sink) {
                        return op.opWrapSink(flags, isParallel(), sink);
                    }

                    @Override
                    public <P_IN> Spliterator<Long> opEvaluateParallelLazy(PipelineHelper<Long> helper,
                                                                 Spliterator<P_IN> spliterator) {
                        return op.opEvaluateParallelLazy(helper, spliterator);
                    }

                    @Override
                    public <P_IN> Node<Long> opEvaluateParallel(PipelineHelper<Long> helper,
                                                         Spliterator<P_IN> spliterator,
                                                         IntFunction<Long[]> generator) {
                        return (Node<Long>) op.opEvaluateParallel(helper, spliterator, generator);
                    }
                };
            case DOUBLE_VALUE:
                return new DoublePipeline.StatefulOp<Object>(upstream, op.inputShape(), op.opGetFlags()) {
                    @Override
                    public Sink opWrapSink(int flags, Sink sink) {
                        return op.opWrapSink(flags, isParallel(), sink);
                    }

                    @Override
                    public <P_IN> Spliterator<Double> opEvaluateParallelLazy(PipelineHelper<Double> helper,
                                                                    Spliterator<P_IN> spliterator) {
                        return op.opEvaluateParallelLazy(helper, spliterator);
                    }

                    @Override
                    public <P_IN> Node<Double> opEvaluateParallel(PipelineHelper<Double> helper,
                                                           Spliterator<P_IN> spliterator,
                                                           IntFunction<Double[]> generator) {
                        return (Node<Double>) op.opEvaluateParallel(helper, spliterator, generator);
                    }
                };
            default: throw new IllegalStateException(op.outputShape().toString());
        }
    }

    default StreamShape inputShape() { return StreamShape.REFERENCE; }

    default StreamShape outputShape() { return StreamShape.REFERENCE; }

    default int opGetFlags() { return 0; }

    Sink<E> opWrapSink(int flags, boolean parallel, Sink<E> sink);

    @SuppressWarnings("unchecked")
    default <P_IN> Spliterator<E> opEvaluateParallelLazy(PipelineHelper<E> helper,
                                                         Spliterator<P_IN> spliterator) {
        return opEvaluateParallel(helper, spliterator, i -> (E[]) new Object[i]).spliterator();
    }

    <P_IN> Node<E> opEvaluateParallel(PipelineHelper<E> helper,
                                      Spliterator<P_IN> spliterator,
                                      IntFunction<E[]> generator);
}
