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package io.polyglotted.common.util;

import com.google.common.collect.ImmutableList;
import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;

import java.util.LinkedList;
import java.util.List;
import java.util.function.Supplier;

import static io.polyglotted.common.util.Assertions.checkGte;
import static io.polyglotted.common.util.ReflectionUtil.fieldValue;
import static java.util.Arrays.asList;

@SuppressWarnings({"unused", "WeakerAccess"})
public interface ListBuilder> {

    @SuppressWarnings("UnusedReturnValue") ListBuilder add(E elem);

    ListBuilder addAll(Iterable elems);

    int size();

    L build();

    default L atleastOne() { checkGte(size(), 1, "size"); return build(); }

    static  ImmutableListBuilder immutableListBuilder() { return new ImmutableListBuilder<>(); }

    static  ImmutableList immutableList() { return ImmutableList.of(); }

    @SafeVarargs static  ImmutableList immutableList(E... elems) { return immutableList(asList(elems)); }

    static  ImmutableList immutableList(Iterable coll) { return ListBuilder.immutableListBuilder().addAll(coll).build(); }

    static  SimpleListBuilder simpleListBuilder() { return simpleListBuilder(LinkedList::new); }

    static  SimpleListBuilder simpleListBuilder(Supplier> supplier) { return new SimpleListBuilder<>(supplier.get()); }

    static  List simpleList() { return new LinkedList<>(); }

    @SafeVarargs static  List simpleList(E... elems) { return simpleList(asList(elems)); }

    static  List simpleList(Iterable coll) { return ListBuilder.simpleListBuilder().addAll(coll).build(); }

    @RequiredArgsConstructor(access = AccessLevel.PRIVATE) class ImmutableListBuilder implements ListBuilder> {
        private final ImmutableList.Builder builder = ImmutableList.builder();

        @Override public ListBuilder> add(E elem) { if (elem != null) builder.add(elem); return this; }

        @Override public ListBuilder> addAll(Iterable elems) { for (E elem : elems) { add(elem); } return this; }

        @Override public int size() { return fieldValue(builder, "size"); }

        @Override public ImmutableList build() { return builder.build(); }
    }

    @RequiredArgsConstructor(access = AccessLevel.PRIVATE) class SimpleListBuilder implements ListBuilder> {
        private final List builder;

        @Override public ListBuilder> add(E elem) { if (elem != null) builder.add(elem); return this; }

        @Override public ListBuilder> addAll(Iterable elems) { for (E elem : elems) { add(elem); } return this; }

        @Override public int size() { return builder.size(); }

        @Override public List build() { return builder; }
    }
}