<?php
/**
 *
 * Copyright © 2016 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Downloadable\Controller\Adminhtml\Downloadable\Product\Edit;

use Magento\Downloadable\Helper\Download as DownloadHelper;

class Link extends \Magento\Catalog\Controller\Adminhtml\Product\Edit
{
    /**
     * @return \Magento\Downloadable\Model\Link
     */
    protected function _createLink()
    {
        return $this->_objectManager->create('Magento\Downloadable\Model\Link');
    }

    /**
     * @return \Magento\Downloadable\Model\Link
     */
    protected function _getLink()
    {
        return $this->_objectManager->get('Magento\Downloadable\Model\Link');
    }

    /**
     * Download process
     *
     * @param string $resource
     * @param string $resourceType
     * @return void
     */
    protected function _processDownload($resource, $resourceType)
    {
        /* @var $helper \Magento\Downloadable\Helper\Download */
        $helper = $this->_objectManager->get('Magento\Downloadable\Helper\Download');
        $helper->setResource($resource, $resourceType);

        $fileName = $helper->getFilename();
        $contentType = $helper->getContentType();

        $this->getResponse()->setHttpResponseCode(
            200
        )->setHeader(
            'Pragma',
            'public',
            true
        )->setHeader(
            'Cache-Control',
            'must-revalidate, post-check=0, pre-check=0',
            true
        )->setHeader(
            'Content-type',
            $contentType,
            true
        );

        if ($fileSize = $helper->getFileSize()) {
            $this->getResponse()->setHeader('Content-Length', $fileSize);
        }

        if ($contentDisposition = $helper->getContentDisposition()) {
            $this->getResponse()
                ->setHeader('Content-Disposition', $contentDisposition . '; filename=' . $fileName);
        }

        $this->getResponse()->clearBody();
        $this->getResponse()->sendHeaders();
        $helper->output();
    }

    /**
     * Download link action
     *
     * @return void
     */
    public function execute()
    {
        $linkId = $this->getRequest()->getParam('id', 0);
        $type = $this->getRequest()->getParam('type', 0);
        /** @var \Magento\Downloadable\Model\Link $link */
        $link = $this->_createLink()->load($linkId);
        if ($link->getId()) {
            $resource = '';
            $resourceType = '';
            if ($type == 'link') {
                if ($link->getLinkType() == DownloadHelper::LINK_TYPE_URL) {
                    $resource = $link->getLinkUrl();
                    $resourceType = DownloadHelper::LINK_TYPE_URL;
                } elseif ($link->getLinkType() == DownloadHelper::LINK_TYPE_FILE) {
                    $resource = $this->_objectManager->get(
                        'Magento\Downloadable\Helper\File'
                    )->getFilePath(
                        $this->_getLink()->getBasePath(),
                        $link->getLinkFile()
                    );
                    $resourceType = DownloadHelper::LINK_TYPE_FILE;
                }
            } else {
                if ($link->getSampleType() == DownloadHelper::LINK_TYPE_URL) {
                    $resource = $link->getSampleUrl();
                    $resourceType = DownloadHelper::LINK_TYPE_URL;
                } elseif ($link->getSampleType() == DownloadHelper::LINK_TYPE_FILE) {
                    $resource = $this->_objectManager->get(
                        'Magento\Downloadable\Helper\File'
                    )->getFilePath(
                        $this->_getLink()->getBaseSamplePath(),
                        $link->getSampleFile()
                    );
                    $resourceType = DownloadHelper::LINK_TYPE_FILE;
                }
            }
            try {
                $this->_processDownload($resource, $resourceType);
            } catch (\Magento\Framework\Exception\LocalizedException $e) {
                $this->messageManager->addError(__('Something went wrong while getting the requested content.'));
            }
        }
    }
}