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/*
 * Copyright (c) 2021 dzikoysk
 *  
 * 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 panda.std.stream;

import org.jetbrains.annotations.Nullable;
import panda.std.Option;
import java.util.Spliterator;
import java.util.function.Consumer;
import java.util.function.Predicate;

final class TakeWhileSpliterator implements Spliterator {

    private final Spliterator source;
    private final Predicate condition;
    private boolean conditionHolds;
    private @Nullable T holdValue;

    TakeWhileSpliterator(Spliterator source, Predicate condition) {
        this.source = source;
        this.condition = condition;
        this.conditionHolds = true;
    }

    @Override
    public boolean tryAdvance(Consumer action) {
        return conditionHolds && source.tryAdvance((element) -> {
            if (condition.test(element)) {
                action.accept(element);
             }
            else {
                conditionHolds = false;
                holdValue = element;
            }
        });
    }

    @Override
    public Spliterator trySplit() {
        return null;
    }

    @Override
    public long estimateSize() {
        return 0;
    }

    @Override
    public int characteristics() {
        return 0;
    }

    public Option getHoldValue() {
        return Option.of(holdValue);
    }

}