module-vendor-sales-report/Block/Adminhtml/Report.php

<?php
namespace Shopkeeper\VendorSalesReport\Block\Adminhtml;

use Magento\Backend\Block\Template;
use Magento\Backend\Block\Template\Context;
use Shopkeeper\VendorSalesReport\Helper\Data as ConfigHelper;

class Report extends Template
{
    /**
     * @var ConfigHelper
     */
    protected $configHelper;

    /**
     * @param Context $context
     * @param ConfigHelper $configHelper
     * @param array $data
     */
    public function __construct(
        Context $context,
        ConfigHelper $configHelper,
        array $data = []
    ) {
        $this->configHelper = $configHelper;
        parent::__construct($context, $data);
    }

    /**
     * Get grid URL
     *
     * @return string
     */
    public function getGridUrl()
    {
        return $this->getUrl('*/*/grid');
    }

    /**
     * Get export URL
     *
     * @return string
     */
    public function getExportUrl()
    {
        return $this->getUrl('*/*/export');
    }

    /**
     * Get configured order statuses
     *
     * @return array
     */
    public function getOrderStatuses()
    {
        return $this->configHelper->getOrderStatus();
    }

    /**
     * Get default start date (first day of last month)
     *
     * @return string
     */
    public function getDefaultStartDate()
    {
        return date('Y-m-01', strtotime('first day of last month'));
    }

    /**
     * Get default end date (last day of last month)
     *
     * @return string
     */
    public function getDefaultEndDate()
    {
        return date('Y-m-t', strtotime('last day of last month'));
    }
}