<?php

declare(strict_types=1);

namespace App\Modules\Files;

use App\Models\User;
use App\Modules\Audit\Action;
use App\Modules\Files\Models\File;
use App\Modules\Files\Uploads\StoreUploadedFile;
use Illuminate\Contracts\Filesystem\Filesystem;
use Illuminate\Support\Facades\Storage;

/**
 * Adopts an orphan in place: a File row for bytes already on disk. Shared
 * by the orphans screen (a ticked selection, in the request) and
 * ImportOrphanFilesJob ("import all", in the background). Which paths are
 * importable is OrphanFileScanner's call.
 */
class OrphanFileImporter
{
    public function __construct(
        private readonly StoreUploadedFile $storeFile,
    ) {}

    public function import(User $user, string $diskName, string $path): File
    {
        $disk = Storage::disk($diskName);

        return $this->storeFile->create(
            uploader: $user,
            originalName: basename($path),
            path: $path,
            mimeType: $disk->mimeType($path) ?: 'application/octet-stream',
            size: $disk->size($path),
            checksum: $this->checksumOf($disk, $path),
            folderId: null,
            disk: $diskName,
            action: Action::FileImported,
        );
    }

    /**
     * Streamed rather than hash_file() on a local path — the only way to
     * checksum a file that might live on a non-local disk (S3 has no
     * local filesystem path to hand hash_file()).
     */
    private function checksumOf(Filesystem $disk, string $path): string
    {
        $stream = $disk->readStream($path);

        if ($stream === null) {
            return '';
        }

        $context = hash_init('sha256');
        hash_update_stream($context, $stream);
        fclose($stream);

        return hash_final($context);
    }
}