<?php
/**
 *
 * part-db version 0.1
 * Copyright (C) 2005 Christoph Lechner
 * http://www.cl-projects.de/
 *
 * part-db version 0.2+
 * Copyright (C) 2009 K. Jacobs and others (see authors.php)
 * http://code.google.com/p/part-db/
 *
 * Part-DB Version 0.4+
 * Copyright (C) 2016 - 2019 Jan Böhmer
 * https://github.com/jbtronics
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 *
 */

namespace App\Services;


use App\Entity\Attachments\Attachment;
use App\Entity\Attachments\AttachmentContainingDBElement;
use App\Entity\Attachments\AttachmentTypeAttachment;
use App\Entity\Attachments\CategoryAttachment;
use App\Entity\Attachments\CurrencyAttachment;
use App\Entity\Attachments\DeviceAttachment;
use App\Entity\Attachments\FootprintAttachment;
use App\Entity\Attachments\GroupAttachment;
use App\Entity\Attachments\ManufacturerAttachment;
use App\Entity\Attachments\MeasurementUnitAttachment;
use App\Entity\Attachments\PartAttachment;
use App\Entity\Attachments\StorelocationAttachment;
use App\Entity\Attachments\SupplierAttachment;
use App\Entity\Attachments\UserAttachment;
use App\Services\Attachments\AttachmentPathResolver;
use Symfony\Component\HttpFoundation\File\UploadedFile;

class AttachmentHelper
{

    protected $pathResolver;

    public function __construct(AttachmentPathResolver $pathResolver)
    {
        $this->pathResolver = $pathResolver;
    }

    /**
     * Gets an SPLFileInfo object representing the file associated with the attachment.
     * @param Attachment $attachment The attachment for which the file should be generated
     * @return \SplFileInfo|null The fileinfo for the attachment file. Null, if the attachment is external or has
     * invalid file.
     */
    public function attachmentToFile(Attachment $attachment) : ?\SplFileInfo
    {
        if ($attachment->isExternal() || !$this->isFileExisting($attachment)) {
            return null;
        }

        return new \SplFileInfo($this->toAbsoluteFilePath($attachment));
    }

    /**
     * Returns the absolute filepath of the attachment. Null is returned, if the attachment is externally saved,
     * or is not existing.
     * @param Attachment $attachment The attachment for which the filepath should be determined
     * @return string|null
     */
    public function toAbsoluteFilePath(Attachment $attachment): ?string
    {
        if (empty($attachment->getPath())) {
            return null;
        }

        if ($attachment->isExternal()) {
            return null;
        }

        $path = $this->pathResolver->placeholderToRealPath($attachment->getPath());

        //realpath does not work with null as argument
        if ($path === null) {
            return null;
        }

        $tmp = realpath($path);
        //If path is not existing realpath returns false.
        if ($tmp === false) {
            return null;
        }
        return $tmp;
    }

    /**
     * Checks if the file in this attachement is existing. This works for files on the HDD, and for URLs
     * (it's not checked if the ressource behind the URL is really existing, so for every external attachment true is returned).
     *
     * @param Attachment $attachment The attachment for which the existence should be checked
     *
     * @return bool True if the file is existing.
     */
    public function isFileExisting(Attachment $attachment): bool
    {
        if (empty($attachment->getPath())) {
            return false;
        }

        return file_exists($this->toAbsoluteFilePath($attachment)) || $attachment->isExternal();
    }

    /**
     * Returns the filesize of the attachments in bytes.
     * For external attachments or not existing attachments, null is returned.
     *
     * @param Attachment $attachment The filesize for which the filesize should be calculated.
     * @return int|null
     */
    public function getFileSize(Attachment $attachment): ?int
    {
        if ($attachment->isExternal()) {
            return null;
        }

        if (!$this->isFileExisting($attachment)) {
            return null;
        }

        $tmp = filesize($this->toAbsoluteFilePath($attachment));
        return  $tmp !== false ? $tmp : null;
    }

    /**
     * Returns a human readable version of the attachment file size.
     * For external attachments, null is returned.
     *
     * @param Attachment $attachment
     * @param int $decimals The number of decimals numbers that should be printed
     * @return string|null A string like 1.3M
     */
    public function getHumanFileSize(Attachment $attachment, $decimals = 2): ?string
    {
        $bytes = $this->getFileSize($attachment);

        if ($bytes == null) {
            return null;
        }

        //Format filesize for human reading
        //Taken from: https://www.php.net/manual/de/function.filesize.php#106569 and slightly modified

        $sz = 'BKMGTP';
        $factor = (int) floor((strlen($bytes) - 1) / 3);
        return sprintf("%.{$decimals}f", $bytes / 1024 ** $factor) . @$sz[$factor];
    }

    /**
     * Generate a path to a folder, where this attachment can save its file.
     * @param Attachment $attachment The attachment for which the folder should be generated
     * @return string The path to the folder (without trailing slash)
     */
    public function generateFolderForAttachment(Attachment $attachment) : string
    {
        $mapping = [PartAttachment::class => 'part', AttachmentTypeAttachment::class => 'attachment_type',
            CategoryAttachment::class => 'category', CurrencyAttachment::class => 'currency',
            DeviceAttachment::class => 'device', FootprintAttachment::class => 'footprint',
            GroupAttachment::class => 'group', ManufacturerAttachment::class => 'manufacturer',
            MeasurementUnitAttachment::class => 'measurement_unit', StorelocationAttachment::class => 'storelocation',
            SupplierAttachment::class => 'supplier', UserAttachment::class => 'user'];

        $path = $this->pathResolver->getMediaPath() . DIRECTORY_SEPARATOR . $mapping[get_class($attachment)] . DIRECTORY_SEPARATOR . $attachment->getElement()->getID();
        return $path;
    }

    /**
     * Moves the given uploaded file to a permanent place and saves it into the attachment
     * @param Attachment $attachment The attachment in which the file should be saved
     * @param UploadedFile|null $file The file which was uploaded
     * @param bool $become_preview_if_empty If this is true, the uploaded attachment can become the preview picture
     * if the of the element, if no was set already.
     * @return Attachment The attachment with the new filepath
     */
    public function upload(Attachment $attachment, ?UploadedFile $file, bool $become_preview_if_empty = true) : Attachment
    {
        //If file is null, do nothing (helpful, so we dont have to check if the file was reuploaded in controller)
        if (!$file) {
            return $attachment;
        }

        $folder = $this->generateFolderForAttachment($attachment);

        //Sanatize filename
        $safeName = transliterator_transliterate('Any-Latin; Latin-ASCII; [^A-Za-z0-9_] remove; Lower()', $attachment->getName());
        $newFilename = $safeName . '-' . uniqid('', false) . '.' . $file->getClientOriginalExtension();

        //Move our temporay attachment to its final location
        $file_path = $file->move($folder, $newFilename)->getRealPath();

        //Make our file path relative to %BASE%
        $file_path = $this->pathResolver->realPathToPlaceholder($file_path);

        //Save the path to the attachment
        $attachment->setPath($file_path);
        //And save original filename
        $attachment->setFilename($file->getClientOriginalName());

        //Check if we should assign this to master picture
        //this is only possible if the attachment is new (not yet persisted to DB)
        if ($become_preview_if_empty && $attachment->getID() === null && $attachment->isPicture()) {
            $element = $attachment->getElement();
            if ($element instanceof AttachmentContainingDBElement && $element->getMasterPictureAttachment() === null) {
                $element->setMasterPictureAttachment($attachment);
            }
        }

        return $attachment;
    }

}