package com.vci.ubcs.codeapply.object;
import java.io.Serializable;
import java.util.List;
import java.util.function.Function;
import java.util.stream.Collectors;

public interface IPage<T> extends Serializable {
	List<OrderItem> orders();

	default boolean optimizeCountSql() {
		return true;
	}

	default boolean optimizeJoinOfCountSql() {
		return true;
	}

	default boolean searchCount() {
		return true;
	}

	default long offset() {
		long current = this.getCurrent();
		return current <= 1L ? 0L : Math.max((current - 1L) * this.getSize(), 0L);
	}

	default Long maxLimit() {
		return null;
	}

	default long getPages() {
		if (this.getSize() == 0L) {
			return 0L;
		} else {
			long pages = this.getTotal() / this.getSize();
			if (this.getTotal() % this.getSize() != 0L) {
				++pages;
			}

			return pages;
		}
	}

	default IPage<T> setPages(long pages) {
		return this;
	}

	List<T> getRecords();

	IPage<T> setRecords(List<T> records);

	long getTotal();

	IPage<T> setTotal(long total);

	long getSize();

	IPage<T> setSize(long size);

	long getCurrent();

	IPage<T> setCurrent(long current);

	default <R> IPage<T> convert(Function<? super T, ? extends R> mapper) {
		List<T> collect = (List)this.getRecords().stream().map(mapper).collect(Collectors.toList());
		return this.setRecords(collect);
	}
	default String countId() {
		return null;
	}
}