/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

package zorm

// Page 分页对象
// Page Pagination object
type Page struct {
	// 当前页码,从1开始
	// Current page number, starting from 1
	PageNo int

	// 每页多少条,默认20条
	// How many items per page, 20 items by default
	PageSize int

	// 数据总条数
	// Total number of data
	TotalCount int

	// 共多少页
	// How many pages
	PageCount int

	// 是否是第一页
	// Is it the first page
	FirstPage bool

	// 是否有上一页
	// Whether there is a previous page
	HasPrev bool

	// 是否有下一页
	// Is there a next page
	HasNext bool

	// 是否是最后一页
	// Is it the last page
	LastPage bool
}

// NewPage 创建Page对象
// NewPage Create Page object
func NewPage() *Page {
	page := Page{}
	page.PageNo = 1
	page.PageSize = 20
	return &page
}

// setTotalCount 设置总条数,计算其他值
// setTotalCount Set the total number of bars, calculate other values
func (page *Page) setTotalCount(total int) {
	page.TotalCount = total
	page.PageCount = (page.TotalCount + page.PageSize - 1) / page.PageSize
	if page.PageNo >= page.PageCount {
		page.LastPage = true
	} else {
		page.HasNext = true
	}
	if page.PageNo > 1 {
		page.HasPrev = true
	} else {
		page.FirstPage = true
	}
}