package common.util;

import com.github.pagehelper.PageInfo;

import com.google.common.collect.Lists;

import org.springframework.util.CollectionUtils;

import java.util.List;

import java.util.function.Function;

import java.util.function.IntFunction;

import java.util.stream.Collectors;

public class PageUtils {

public static <T, R> PageInfo<R> convertPageInfo(PageInfo<T> sourcePage, List<R> list) {

if (sourcePage == null) {

return new PageInfo<>();

}

PageInfo<R> newPageInfo = CommonBeanUtil.copyProperties(sourcePage, PageInfo::new);

if (newPageInfo == null || CollectionUtils.isEmpty(list)) {

newPageInfo.setList(list);

return newPageInfo;

}

newPageInfo.setList(list);

return newPageInfo;

}

public static <T, R> PageInfo<R> convertPageInfo(PageInfo<T> sourcePage, Function<T, R> function) {

if (sourcePage == null) {

return new PageInfo<>();

}

PageInfo<R> newPageInfo = CommonBeanUtil.copyProperties(sourcePage, PageInfo::new);

if (newPageInfo == null || sourcePage.getList() == null) {

return newPageInfo;

}

newPageInfo.setList(sourcePage.getList().stream().map(function).collect(Collectors.toList()));

return newPageInfo;

}

public static <T> List<T> getPageInfoTotalList(IntFunction<PageInfo<T>> intFunction) {

List<T> list = Lists.newArrayList();

int pageNum = 1;

PageInfo<T> pageInfo;

do {

pageInfo = intFunction.apply(pageNum++);

if (pageInfo == null) {

break;

}

list.addAll(pageInfo.getList());

} while (pageInfo.isHasNextPage());

return list;

}

}