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

@Component({
    selector: 'ace-data-table-paginator',
    templateUrl: './paginator.component.html',
    styleUrls: ['./paginator.component.css'],
})
export class PaginatorComponent implements OnChanges {
    @Input()
    currentPage: number;
    @Input()
    pageSize: number;
    @Input()
    maxResults: number;
    @Input()
    top: boolean;
    @Input()
    parentId: string;
    @Output()
    newPage = new EventEmitter<number>();

    private maxPage: number;
    private pageLinks: Array<number>;

    constructor() {
    }

    ngOnChanges(): void {
        this.maxPage = Math.ceil(this.maxResults / this.pageSize);
        this.pageLinks = [];
        const startPage = Math.max(1, this.currentPage -
            (this.currentPage + 5 > this.maxPage ?
                9 - (this.maxPage - this.currentPage) : 5));
        const endPage = Math.min(this.maxPage,
            this.currentPage < 7 ? 10 : (this.currentPage + 4));

        for (let i = startPage, j = endPage; i <=
        j; i++) {
            this.pageLinks.push(i);
        }
    }

    setPage(e: Event, i: number): void {
        e.preventDefault();
        this.newPage.emit(i);
    }
}