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package com.github.dennisit.vplus.data.utils;

import com.baomidou.mybatisplus.mapper.EntityWrapper;
import com.baomidou.mybatisplus.plugins.Page;
import com.baomidou.mybatisplus.service.IService;
import com.github.dennisit.vplus.data.page.Pagination;
import com.google.common.collect.Lists;
import org.springframework.util.Assert;

import java.util.List;

/**
 * Created by Elon.su on 17/10/28.
 */
public class PaginationUtils {

    /**
     * 将mybatisplus分页模型转换成vplus分页模型
     * @param page mybatisplus分页模型
     * @param  对象集合
     * @return 目标分页实体
     */
    public static  Pagination builder(Page page){
        if(null == page){
            return Pagination.empty();
        }

        return new Pagination<>(page.getRecords(), page.getTotal(), page.getCurrent(), page.getSize());
    }

    /**
     * 构建分页查询对象
     * @param service 服务接口
     * @param page 页码
     * @param size 页量
     * @param wrapper 查询条件
     * @param  泛型约束
     * @return page对象
     */
    public static  Pagination selectPagination(IService service, int page, int size, EntityWrapper wrapper){
        Assert.notNull(service, "服务接口实现不能为空");
        Assert.notNull(wrapper, "查询条件不能为空");

        return builder(service.selectPage(new Page<>(Math.abs(page), Math.abs(size)), wrapper));
    }


    /**
     * 获取分页数据集合
     * @param page 分页实体
     * @param  对象元素
     * @return page页中的集合
     */
    public static  List items(Page page){
        if(null == page){
            return Lists.newArrayList();
        }

        return page.getRecords();
    }


    /**
     * 获取分页数据集合
     * @param pagination 分页实体
     * @param  对象元素
     * @return page页中的集合
     */
    public static  List items(Pagination pagination){
        if(null == pagination){
            return Lists.newArrayList();
        }

        return pagination.getItems();
    }


    /**
     * 抽取分页查询后的list集合
     * @param service 业务接口
     * @param page 页码
     * @param size 页量
     * @param wrapper 查询条件
     * @param  查询实体
     * @return page页中的集合
     */
    public static  List items(IService service, int page, int size, EntityWrapper wrapper){
        Assert.notNull(service, "服务接口实现不能为空");
        Assert.notNull(wrapper, "查询条件不能为空");

        return items(service.selectPage(new Page<>(Math.abs(page), Math.abs(size)), wrapper));
    }


}