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// ============================================================================
// Copyright (c) 2017-2019 Nawapunth Manusitthipol (NawaMan - http://nawaman.net).
// ----------------------------------------------------------------------------
// MIT License
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
// ============================================================================
package functionalj.stream;

import java.util.Iterator;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import functionalj.function.Func1;
import functionalj.function.FuncUnit1;
import functionalj.list.FuncList;
import functionalj.result.Result;
import lombok.val;

@FunctionalInterface
public interface IteratorPlus extends Iterator {
    
    @SuppressWarnings("unchecked")
    public static  IteratorPlus of(D ... ds) {
        return IteratorPlus.from(StreamPlus.of(ds));
    }
    public static  IteratorPlus from(Stream stream) {
        val iterator 
                = (stream instanceof StreamPlus) 
                ? ((StreamPlus)stream).__iterator()
                : stream.iterator();
        return from(iterator);
    }
    public static  IteratorPlus from(Iterator iterator) {
        if (iterator instanceof IteratorPlus)
             return (IteratorPlus)iterator;
        else return (IteratorPlus)(()->iterator);
    }
    
    public Iterator asIterator();
    
    public default IteratorPlus iterator() {
        return IteratorPlus.from(asIterator());
    }
    
    @Override
    public default boolean hasNext() {
        return asIterator().hasNext();
    }
    
    @Override
    public default DATA next() {
        return asIterator().next();
    }
    
    public default StreamPlus stream() {
        val iterable = (Iterable)()->this;
        return StreamPlus.from(StreamSupport.stream(iterable.spliterator(), false));
    }
    
    public default FuncList toList() {
        return stream().toList();
    }
    
    public default Result pullNext() {
        if (hasNext())
             return Result.valueOf(next());
        else return Result.ofNoMore();
    }
    
    @SuppressWarnings("unchecked")
    public default Result> pullNext(int count) {
        Object[] array = stream().limit(count).toArray();
        if ((array.length == 0) && count != 0)
            return Result.ofNoMore();
        
        val iterator = (ArrayBackedIteratorPlus)new ArrayBackedIteratorPlus(array);
        return Result.valueOf(iterator);
    }
    
    public default IteratorPlus useNext(FuncUnit1 usage) {
        if (hasNext()) {
            val next = next();
            usage.accept(next);
        }
        
        return this;
    }
    
    public default IteratorPlus useNext(int count, FuncUnit1> usage) {
        Object[] array = stream().limit(count).toArray();
        if ((array.length != 0) || count == 0) {
            @SuppressWarnings("unchecked")
            val iterator = (ArrayBackedIteratorPlus)new ArrayBackedIteratorPlus(array);
            val stream   = iterator.stream();
            usage.accept(stream);
        }
        
        return this;
    }
    
    public default  Result mapNext(Func1 mapper) {
        if (hasNext()) {
            val next  = next();
            val value = mapper.apply(next);
            return Result.valueOf(value);
        } else {
            return Result.ofNoMore();
        }
    }
    
    public default  Result mapNext(int count, Func1, TARGET> mapper) {
        val array = stream().limit(count).toArray();
        if ((array.length == 0) && (count != 0))
            return Result.ofNoMore();
        
        @SuppressWarnings("unchecked")
        val input  = (IteratorPlus)ArrayBackedIteratorPlus.from(array);
        val stream = input.stream();
        val value = mapper.apply(stream);
        return Result.valueOf(value);
    }
    
}