<?php
namespace Vichan\Service\Media;

use Vichan\Data\{MediaInstallResult, ThumbGenerationResult};
use Vichan\Functions\Metadata;


class MimeMapMediaHandler implements MediaHandler {
	use MediaHandlerTrait;

	/**
	 * @var callable(string): ?string
	 */
	private mixed $mime_mapper;

	private static function getShape(string $file_path) {
		$ret = \getimagesize($file_path);
		if ($ret === false) {
			throw new MediaException("Could not read image sizes of '$file_path'", MediaException::ERR_NO_OPEN);
		}
		if ($ret[2] == \IMAGETYPE_UNKNOWN) {
			throw new \RuntimeException("Error '$file_path' is not an image", MediaException::ERR_BAD_MEDIA_TYPE);
		}

		$width = $ret[0];
		$height = $ret[1];
		$mime = $ret['mime'];
		return [ $width, $height, $mime ];
	}

	private function generateThumbImpl(
		string $source_file_mime,
		int $max_width,
		int $max_height
	): ThumbGenerationResult {
		$thumb_path = ($this->mime_mapper)($source_file_mime);
		list($thumb_width, $thumb_height, $thumb_mime) = self::getShape($thumb_path);

		return new ThumbGenerationResult(
			$thumb_path,
			$thumb_mime,
			\min($thumb_width, $max_width),
			\min($thumb_height, $max_height)
		);
	}

	public function __construct(callable $mime_mapper) {
		$this->mime_mapper = $mime_mapper;
	}

	public function supportsMime(string $mime): bool {
		return ($this->mime_mapper)($mime) !== null;
	}

	public function openHandle(string $file_path, string $file_mime, int $file_kind): mixed {
		return [ $file_path, $file_mime, $file_kind ];
	}

	public function closeHandle(mixed $handle) {
		// No-op
	}

	public function installMediaAndGenerateThumb(
		mixed $handle,
		string $media_preferred_out_file_basepath,
		string $thumb_preferred_out_file_basepath,
		int $thumb_max_width,
		int $thumb_max_height
	): MediaInstallResult {
		list($source_file_path, $source_file_mime, $source_file_kind) = $handle;
		$out_path = $media_preferred_out_file_basepath . '.' . Metadata\mime_to_ext($source_file_mime);

		$this->move_or_link_or_copy($source_file_kind, $source_file_path, $out_path);

		$thumb = $this->generateThumbImpl(
			$source_file_mime,
			$thumb_max_width,
			$thumb_max_height
		);
		return new MediaInstallResult($thumb, $out_path);
	}

	public function generateThumb(
		mixed $handle,
		string $preferred_out_file_basepath,
		int $max_width,
		int $max_height
	): ThumbGenerationResult {
		return $this->generateThumbImpl($handle[1], $max_width, $max_height);
	}
}