<?php

namespace Kirby\Image\Darkroom;

use claviska\SimpleImage;
use Kirby\Filesystem\Mime;
use Kirby\Image\Darkroom;

/**
 * GdLib
 *
 * @package   Kirby Image
 * @author    Bastian Allgeier <bastian@getkirby.com>
 * @link      https://getkirby.com
 * @copyright Bastian Allgeier
 * @license   https://opensource.org/licenses/MIT
 */
class GdLib extends Darkroom
{
	/**
	 * Processes the image with the SimpleImage library
	 */
	public function process(string $file, array $options = []): array
	{
		$options = $this->preprocess($file, $options);
		$mime    = $this->mime($options);

		$image = new SimpleImage();
		$image->fromFile($file);

		$image = $this->resize($image, $options);
		$image = $this->autoOrient($image, $options);
		$image = $this->blur($image, $options);
		$image = $this->grayscale($image, $options);

		$image->toFile($file, $mime, $options);

		return $options;
	}

	/**
	 * Activates the autoOrient option in SimpleImage
	 * unless this is deactivated
	 */
	protected function autoOrient(SimpleImage $image, array $options): SimpleImage
	{
		if ($options['autoOrient'] === false) {
			return $image;
		}

		return $image->autoOrient();
	}

	/**
	 * Wrapper around SimpleImage's resize and crop methods
	 */
	protected function resize(SimpleImage $image, array $options): SimpleImage
	{
		if ($options['crop'] === false) {
			return $image->resize($options['width'], $options['height']);
		}

		return $image->thumbnail(
			$options['width'],
			$options['height'] ?? $options['width'],
			$options['crop']
		);
	}

	/**
	 * Applies the correct blur settings for SimpleImage
	 */
	protected function blur(SimpleImage $image, array $options): SimpleImage
	{
		if ($options['blur'] === false) {
			return $image;
		}

		return $image->blur('gaussian', (int)$options['blur']);
	}

	/**
	 * Applies grayscale conversion if activated in the options.
	 */
	protected function grayscale(SimpleImage $image, array $options): SimpleImage
	{
		if ($options['grayscale'] === false) {
			return $image;
		}

		return $image->desaturate();
	}

	/**
	 * Returns mime type based on `format` option
	 */
	protected function mime(array $options): string|null
	{
		if ($options['format'] === null) {
			return null;
		}

		return Mime::fromExtension($options['format']);
	}
}
