import { Component, OnInit, Input, Output, EventEmitter } from '@angular/core';

@Component({
  selector: 'app-page',
  templateUrl: './page.component.html',
  styleUrls: ['./page.component.less']
})
export class PageComponent implements OnInit {

	@Input() pageData;
	@Output() fromChild = new EventEmitter();
	curPage;
	maxPage;
	page = {
		list: [],
	};
	constructor() { }

	ngOnInit() {
		if (!this.pageData.size) {
		  this.pageData.size = 10;
		}
		if (!this.pageData.total) {
		  this.pageData.total = 0;
		}
		this.pageList();
		this.update(1, this.pageData.size);
	}

	update(num, size) {
		num = parseInt(num);
		if (num < 1 || (num > this.maxPage && this.maxPage !== 0)) {
	  		return;
		}
		this.pageData.num = num;
		this.fromChild.emit({
		  num: num
		});
		this.pageList();
	}

	pageList() {
		this.maxPage = this.maxPage = Math.ceil(this.pageData.total / this.pageData.size);
		const tempArray = [];
		for (let i = 1; i <= parseInt(this.maxPage); i++) {
			if (this.pageData.num - i >= 3 && i !== 1) {// 只显示当前页前三个页码
				tempArray.push(0);
				i = this.pageData.num - 3; // 将页码跳到没有省略的页码
			} else {
				if (i >= this.pageData.num + 3 && i !== this.maxPage) { // 只显示当前页的后两个页码
				  tempArray.push(0);
				  i = this.maxPage;  // 将页码跳到最后一页
				}
				tempArray.push(i);
			}
		}
		this.page.list = tempArray;
	};

}