<?php

// {{{ License

// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.

// }}}

namespace Component\Media;

use App\Core\Cache;
use App\Core\DB\DB;
use function App\Core\I18n\_m;
use App\Core\Log;
use App\Entity\Attachment;
use App\Entity\Avatar;
use App\Util\Common;
use App\Util\Exception\ClientException;
use Component\Media\Exception\NoAvatarException;
use Exception;
use Symfony\Component\Asset\Package;
use Symfony\Component\Asset\VersionStrategy\EmptyVersionStrategy;
use Symfony\Component\HttpFoundation\BinaryFileResponse;
use Symfony\Component\HttpFoundation\File\File as SymfonyFile;
use Symfony\Component\HttpFoundation\HeaderUtils;
use Symfony\Component\HttpFoundation\Response;

abstract class Utils
{
    /**
     * Perform file validation (checks and normalization) and store the given file
     */
    public static function validateAndStoreAttachment(SymfonyFile $sfile,
                                                      string $dest_dir,
                                                      ?string $title = null,
                                                      bool $is_local = true,
                                                      ?int $actor_id = null): Attachment
    {
        // The following properly gets the mimetype with `file` or other
        // available methods, so should be safe
        $hash = hash_file(Attachment::FILEHASH_ALGO, $sfile->getPathname());
        $file = Attachment::create([
            'file_hash' => $hash,
            'actor_id'  => $actor_id,
            'mimetype'  => $sfile->getMimeType(),
            'title'     => $title ?: _m('Untitled attachment'),
            'filename'  => $hash,
            'is_local'  => $is_local,
        ]);
        $sfile->move($dest_dir, $hash);
        // TODO Normalize file types
        return $file;
    }

    /**
     * Include $filepath in the response, for viewing or downloading.
     *
     * @throws ServerException
     */
    public static function sendFile(string $filepath, string $mimetype, ?string $output_filename, string $disposition = 'inline'): Response
    {
        $response = new BinaryFileResponse(
            $filepath,
            Response::HTTP_OK,
            [
                'Content-Description' => 'File Transfer',
                'Content-Type'        => $mimetype,
                'Content-Disposition' => HeaderUtils::makeDisposition($disposition, $output_filename ?: _m('Untitled attachment')),
                'Cache-Control'       => 'public',
            ],
            $public = true,
            $disposition = null,
            $add_etag = true,
            $add_last_modified = true
        );
        if (Common::config('site', 'x_static_delivery')) {
            $response->trustXSendfileTypeHeader();
        }
        return $response;
    }

    /**
     * Throw a client exception if the cache key $id doesn't contain
     * exactly one entry
     *
     * @param mixed $except
     * @param mixed $id
     */
    private static function error($except, $id, array $res)
    {
        switch (count($res)) {
        case 0:
            throw new $except();
        case 1:
            return $res[0];
        default:
            Log::error('Media query returned more than one result for identifier: \"' . $id . '\"');
            throw new ClientException(_m('Internal server error'));
        }
    }

    /**
     * Get the file info by id
     *
     * Returns the file's hash, mimetype and title
     */
    public static function getFileInfo(int $id)
    {
        return self::error(NoSuchFileException::class,
                           $id,
                           Cache::get("file-info-{$id}",
                                      function () use ($id) {
                                          return DB::dql('select at.file_hash, at.mimetype, at.title ' .
                                                         'from App\\Entity\\Attachment at ' .
                                                         'where at.id = :id',
                                                         ['id' => $id]);
                                      }));
    }

    // ----- Attachment ------

    /**
     * Get the attachment file info by id
     *
     * Returns the attachment file's hash, mimetype, title and path
     */
    public static function getAttachmentFileInfo(int $id): array
    {
        $res              = self::getFileInfo($id);
        $res['file_path'] = Common::config('attachments', 'dir') . $res['file_hash'];
        return $res;
    }

    // ----- Avatar ------

    /**
     * Get the avatar associated with the given nickname
     */
    public static function getAvatar(?string $nickname = null): Avatar
    {
        $nickname = $nickname ?: Common::userNickname();
        return self::error(NoAvatarException::class,
                           $nickname,
                           Cache::get("avatar-{$nickname}",
                                      function () use ($nickname) {
                                          return DB::dql('select a from App\\Entity\\Avatar a ' .
                                                         'join App\Entity\GSActor g with a.gsactor_id = g.id ' .
                                                         'where g.nickname = :nickname',
                                                         ['nickname' => $nickname]);
                                      }));
    }

    /**
     * Get the cached avatar associated with the given nickname, or the current user if not given
     */
    public static function getAvatarUrl(?string $nickname = null): string
    {
        $nickname = $nickname ?: Common::userNickname();
        return Cache::get("avatar-url-{$nickname}", function () use ($nickname) {
            try {
                return self::getAvatar($nickname)->getUrl();
            } catch (NoAvatarException $e) {
            }
            $package = new Package(new EmptyVersionStrategy());
            return $package->getUrl(Common::config('avatar', 'default'));
        });
    }

    /**
     * Get the cached avatar file info associated with the given nickname
     *
     * Returns the avatar file's hash, mimetype, title and path.
     * Ensures exactly one cached value exists
     */
    public static function getAvatarFileInfo(string $nickname): array
    {
        try {
            $res = self::error(NoAvatarException::class,
                               $nickname,
                               Cache::get("avatar-file-info-{$nickname}",
                                          function () use ($nickname) {
                                              return DB::dql('select f.file_hash, f.mimetype, f.title ' .
                                                             'from App\\Entity\\Attachment f ' .
                                                             'join App\\Entity\\Avatar a with f.id = a.file_id ' .
                                                             'join App\\Entity\\GSActor g with g.id = a.gsactor_id ' .
                                                             'where g.nickname = :nickname',
                                                             ['nickname' => $nickname]);
                                          }));
            $res['file_path'] = Avatar::getFilePathStatic($res['file_hash']);
            return $res;
        } catch (Exception $e) {
            $filepath = INSTALLDIR . '/public/assets/default-avatar.svg';
            return ['file_path' => $filepath, 'mimetype' => 'image/svg+xml', 'title' => null];
        }
    }

    // ------------------------------

    /**
     * Get the minor part of a mimetype. image/webp -> image
     */
    public static function mimetypeMajor(string $mime)
    {
        return explode('/', self::mimeBare($mime))[0];
    }

    /**
     * Get the minor part of a mimetype. image/webp -> webp
     */
    public static function mimetypeMinor(string $mime)
    {
        return explode('/', self::mimeBare($mime))[1];
    }

    /**
     *  Get only the mimetype and not additional info (separated from bare mime with semi-colon)
     */
    public static function mimeBare(string $mimetype)
    {
        $mimetype = mb_strtolower($mimetype);
        if (($semicolon = mb_strpos($mimetype, ';')) !== false) {
            $mimetype = mb_substr($mimetype, 0, $semicolon);
        }
        return trim($mimetype);
    }
}