# /src/Acme/Bundle/CustomBundle/FileTransformer/Transformation/Image/Watermark.php
<?php

namespace Acme\CustomBundle\FileTransformer\Transformation\Image;

use Akeneo\Component\FileTransformer\Options\TransformationOptionsResolverInterface;
use Akeneo\Component\FileTransformer\Transformation\AbstractTransformation;
use Akeneo\Component\FileTransformer\Transformation\Image\ImageMagickLauncher;

/**
 * Watermark transformation
 */
class Watermark extends AbstractTransformation
{
    /** @var ImageMagickLauncher */
    protected $launcher;

    /**
     * @param TransformationOptionsResolverInterface $optionsResolver
     * @param ImageMagickLauncher                    $launcher
     * @param array                                  $supportedMimeTypes
     */
    public function __construct(
        TransformationOptionsResolverInterface $optionsResolver,
        ImageMagickLauncher $launcher,
        array $supportedMimeTypes = ['image/jpeg', 'image/png']
    ) {
        $this->optionsResolver    = $optionsResolver;
        $this->supportedMimeTypes = $supportedMimeTypes;
        $this->launcher           = $launcher;
    }

    /**
     * $options = [
     *      'font'      => 'Arial'   by default
     *      'size'      => '12'      by default
     *      'watermark' => 'my mark' what you want to write in watermark
     * ];
     *
     * {@inheritdoc}
     */
    public function transform(\SplFileInfo $file, array $options = [])
    {
        $options  = $this->optionsResolver->resolve($options);

        $fontPart = '-font ' . $options['font'];
        $sizePart = '-pointsize ' . $options['size'];
        $blackWatermarkPart = 'fill black text ' . $options['positionBlack'] . ' \'' . $options['watermark'] . '\'';
        $whiteWatermarkPart = 'fill white text ' . $options['positionWhite'] . ' \'' . $options['watermark'] . '\'';
        $drawPart = '-draw "gravity south ' . $blackWatermarkPart . ' ' . $whiteWatermarkPart . '"';
        $cmd = $fontPart . ' ' . $sizePart . ' ' . $drawPart;

        $this->launcher->convert($cmd, $file->getPathname());
    }

    /**
     * {@inheritdoc}
     */
    public function getName()
    {
        return 'watermark';
    }
}

#/src/Acme/Bundle/CustomBundle/FileTransformer/Options/Image/WatermarkOptionsResolver.php
<?php

namespace Acme\CustomBundle\FileTransformer\Options\Image;

use Akeneo\Component\FileTransformer\Exception\InvalidOptionsTransformationException;
use Akeneo\Component\FileTransformer\Options\TransformationOptionsResolverInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

/**
 * Watermark Options Resolver
 */
class WatermarkOptionsResolver implements TransformationOptionsResolverInterface
{
    /** @var OptionsResolver */
    protected $resolver;

    public function __construct()
    {
        $this->resolver = new OptionsResolver();
        $this->resolver->setRequired([
            'font',
            'size',
            'watermark',
            'positionBlack',
            'positionWhite',
        ]);
        $this->resolver->setAllowedTypes([
            'font'          => 'string',
            'size'          => 'string',
            'watermark'     => 'string',
            'positionBlack' => 'string',
            'positionWhite' => 'string',
        ]);
        $this->resolver->setDefaults([
            'font'          => 'Arial',
            'size'          => '12',
            'watermark'     => 'Copyright',
            'positionBlack' => '0,45',
            'positionWhite' => '1,43',
        ]);
    }

    /**
     * {@inheritdoc}
     */
    public function resolve(array $options)
    {
        try {
            $options = $this->resolver->resolve($options);
        } catch (\Exception $e) {
            throw InvalidOptionsTransformationException::general($e, 'watermark');
        }

        return $options;
    }
}