<?php

namespace App\Models;

use App\Events\UploadFile;
use App\Http\Requests\UploadRequest;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Event;
use Symfony\Component\HttpFoundation\File\File as SymphonyFile;
use Symfony\Component\HttpFoundation\File\UploadedFile;

/**
 * Class File
 */
class File extends Model
{
    /**
     * Hash algorithm used for hashing file
     */
    const HASH_ALGORITHM = 'sha256';
    /**
     * @var bool $timstamps have created_at and updated_at fields
     */
    public $timestamps = true;
    protected $fillable = [
        'user_id',
        'filename',
        'original_filename',
        'file_hash',
        'hash_algorithm',
        'mime_type',
        'description',
        'keywords',
        'directory'
    ];
    protected $guarded = [];

    /**
     * Getter for filename of uploaded file.
     *
     * This filename is used for localy stored file.
     *
     * @param UploadedFile $file
     *
     * @return string
     */
    public function getFilename(UploadedFile $file)
    {
        return uniqid() . '.' . $file->getClientOriginalExtension();
    }

    /**
     * Saves file into FS and creates new record in database
     *
     * @param UploadedFile  $file
     * @param UploadRequest $request
     *
     * @return array associative array - key 'file' is type of SymphonyFile and contains info about real file, key 'id'
     *               is ID of row in files table
     */
    public function upload(UploadedFile $file, UploadRequest $request)
    {
        $destination = config('app.upload_path');
        $filename = $this->getFilename($file);

        // save file into physical location (local FS)
        $uploadedFile = $file->move($destination, $filename);

        // insert record into database
        $id = $this->saveIntoDatabase($uploadedFile, $request, $file->getClientOriginalName());

        // fire event about new file
        Event::fire(new UploadFile($uploadedFile, $id));

        return [
            'file' => $file,
            'id'   => $id
        ];
    }

    /**
     * Save file into database
     *
     * This file saves new record into database. It also calculates hash of given file, obtains MIME type etc.
     *
     * @param SymphonyFile  $file
     * @param UploadRequest $request
     * @param               $originalFilename
     *
     * @return mixed
     */
    protected function saveIntoDatabase(SymphonyFile $file, UploadRequest $request, $originalFilename)
    {
        // get path and hash of uploaded file
        $path = config('app.upload_path') . DIRECTORY_SEPARATOR . $file->getFilename();
        $hash = hash_file(self::HASH_ALGORITHM, $path);

        // define mandatory fields
        $params = [
            'user_id'           => Auth::user()->id,
            'filename'          => $file->getFilename(),
            'original_filename' => $originalFilename,
            'file_hash'         => $hash,
            'hash_algorithm'    => self::HASH_ALGORITHM,
            'mime_type'         => $file->getMimeType(),
        ];

        // save optional fields
        $optionalFields = ['description', 'keywords', 'directory'];
        foreach ($optionalFields as $field) {
            if ($request->has($field)) {
                $params[$field] = $request->$field;
            }
        }

        // create new database row
        $newFile = File::create($params);

        return $newFile->id;
    }
}