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The module for FunctionalJ Core.
There is a newer version: 1.0.17
// ============================================================================
// Copyright (c) 2017-2021 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.lens.lenses;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;

import functionalj.function.Func1;
import functionalj.lens.core.AccessParameterized;
import functionalj.lens.core.LensSpec;
import functionalj.lens.core.LensSpecParameterized;
import functionalj.lens.core.LensUtils;
import functionalj.lens.core.WriteLens;
import lombok.val;


@FunctionalInterface
public interface ListLens>
        extends
            ObjectLens>,
            ListAccess {
    
    
    public static > 
            ListLens of(
                Function>               read,
                WriteLens>              write,
                Function, TYPELENS> subCreator) {
        return LensUtils.createListLens(read, write, subCreator);
    }
    public static > 
            ListLens of(LensSpecParameterized, TYPE, TYPELENS> spec) {
        return new ListLens() {
            @Override
            public LensSpecParameterized, TYPE, TYPELENS> lensSpecParameterized() {
                return spec;
            }
        };
    }
    
    public LensSpecParameterized, TYPE, TYPELENS> lensSpecParameterized();
    
    public default AccessParameterized, TYPE, TYPELENS> accessParameterized() {
        return lensSpecParameterized();
    }
    
    @Override
    public default TYPELENS createSubAccess(Function, TYPE> accessToSub) {
        return accessParameterized().createSubAccess(accessToSub);
    }
    
    @Override
    public default LensSpec> lensSpec() {
        return lensSpecParameterized().getSpec();
    }
    
    @Override
    public default List applyUnsafe(HOST host) throws Exception {
        return lensSpec().getRead().apply(host);
    }
    
    public default TYPELENS createSubLens(Function, TYPE> readSub, WriteLens, TYPE> writeSub) {
        return LensUtils.createSubLens(this, readSub, writeSub, lensSpecParameterized()::createSubLens);
    }
    
    public default TYPELENS first() {
        return at(0);
    }
    
    public default TYPELENS last() {
        return createSubLens(
                (list) -> {
                    if (list == null)
                        return null;
                    if (list.isEmpty())
                        return null;
                    return list.get(list.size() - 1);
                },
                (list, newValue)->{
                    val newList = new ArrayList<>(list);
                    newList.set(list.size() - 1, newValue);
                    return newList;
                });
    }
    
    public default TYPELENS at(int index) {
        return createSubLens(
                (list) -> {
                    if (list == null)
                        return null;
                    if (list.isEmpty())
                        return null;
                    if (index < 0) 
                        return null;
                    if (index >= list.size())
                        return null;
                    return list.get(index);
                },
                (list, newValue)->{
                    val newList = new ArrayList<>(list);
                    newList.set(index, newValue);
                    return newList;
                });
    }
    
    public default Func1 changeTo(Predicate checker, Function mapper) {
        return host -> {
            val newList = apply(host).stream()
                    .map(each -> checker.test(each) ? mapper.apply(each) : each)
                    .collect(Collectors.toList());
            val newHost = apply(host, newList);
            return newHost;
        };
    }
    
}