<?php
declare(strict_types=1);

namespace App\Service;

use Symfony\Component\DependencyInjection\Attribute\Autowire;
use Symfony\Component\Filesystem\Filesystem;

class CoverStorage {
	public const array EXTENSIONS = [
		'image/jpeg' => 'jpg',
		'image/png' => 'png',
		'image/webp' => 'webp',
	];

	public function __construct(
		#[Autowire('%app.cover_originals_dir%')]
		private readonly string           $originalsDir,
		#[Autowire('%app.cover_thumbnails_dir%')]
		private readonly string           $thumbnailsDir,
		private readonly CoverThumbnailer $thumbnailer,
		private readonly Filesystem       $filesystem,
	) {
	}

	/**
	 * @param string $contents the image, kept byte for byte as the original
	 *
	 * @return string the name of the stored cover
	 *
	 * @throws CoverProcessingException
	 */
	public function store(string $contents): string {
		// The extension comes from the detected content, never from the client's file name.
		$extension = self::EXTENSIONS[@getimagesizefromstring($contents)['mime'] ?? ''] ?? null;

		if ($extension === null) {
			throw new CoverProcessingException('Unsupported image type.');
		}

		$name = bin2hex(random_bytes(16)) . '.' . $extension;
		$this->filesystem->mkdir([$this->originalsDir, $this->thumbnailsDir]);

		try {
			$this->thumbnailer->createThumbnails(
				$contents,
				fn(string $size): string => $this->thumbnailPath($name, $size),
			);
			$this->filesystem->dumpFile($this->originalPath($name), $contents);
		} catch (\Throwable $exception) {
			$this->delete($name);

			throw $exception;
		}

		return $name;
	}

	public function delete(string $name): void {
		$this->filesystem->remove([
			$this->originalPath($name),
			...array_map(
				fn(string $size): string => $this->thumbnailPath($name, $size),
				array_keys(CoverThumbnailer::SIZES),
			),
		]);
	}

	public function originalPath(string $name): string {
		return $this->originalsDir . '/' . $name;
	}

	public function thumbnailPath(string $name, string $size): string {
		return $this->thumbnailsDir . '/' . $name . '.' . $size . '.jpg';
	}
}