class RotateImageEffect

class RotateImageEffect extends ConfigurableImageEffectBase {
    
    /**
     * {@inheritdoc}
     */
    public function applyEffect(ImageInterface $image) {
        if (!empty($this->configuration['random'])) {
            $degrees = abs((double) $this->configuration['degrees']);
            $this->configuration['degrees'] = rand(-$degrees, $degrees);
        }
        if (!$image->rotate($this->configuration['degrees'], $this->configuration['bgcolor'])) {
            $this->logger
                ->error('Image rotate failed using the %toolkit toolkit on %path (%mimetype, %dimensions)', [
                '%toolkit' => $image->getToolkitId(),
                '%path' => $image->getSource(),
                '%mimetype' => $image->getMimeType(),
                '%dimensions' => $image->getWidth() . 'x' . $image->getHeight(),
            ]);
            return FALSE;
        }
        return TRUE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function transformDimensions(array &$dimensions, $uri) {
        // If the rotate is not random and current dimensions are set,
        // then the new dimensions can be determined.
        if (!$this->configuration['random'] && $dimensions['width'] && $dimensions['height']) {
            $rect = new Rectangle($dimensions['width'], $dimensions['height']);
            $rect = $rect->rotate($this->configuration['degrees']);
            $dimensions['width'] = $rect->getBoundingWidth();
            $dimensions['height'] = $rect->getBoundingHeight();
        }
        else {
            $dimensions['width'] = $dimensions['height'] = NULL;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSummary() {
        $summary = [
            '#theme' => 'image_rotate_summary',
            '#data' => $this->configuration,
        ];
        $summary += parent::getSummary();
        return $summary;
    }
    
    /**
     * {@inheritdoc}
     */
    public function defaultConfiguration() {
        return [
            'degrees' => 0,
            'bgcolor' => NULL,
            'random' => FALSE,
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
        $form['degrees'] = [
            '#type' => 'number',
            '#default_value' => $this->configuration['degrees'],
            '#title' => $this->t('Rotation angle'),
            '#description' => $this->t('The number of degrees the image should be rotated. Positive numbers are clockwise, negative are counter-clockwise.'),
            '#field_suffix' => '°',
            '#required' => TRUE,
        ];
        $form['bgcolor'] = [
            '#type' => 'textfield',
            '#default_value' => $this->configuration['bgcolor'],
            '#title' => $this->t('Background color'),
            '#description' => $this->t('The background color to use for exposed areas of the image. Use web-style hex colors (#FFFFFF for white, #000000 for black). Leave blank for transparency on image types that support it.'),
            '#size' => 7,
            '#maxlength' => 7,
        ];
        $form['random'] = [
            '#type' => 'checkbox',
            '#default_value' => $this->configuration['random'],
            '#title' => $this->t('Randomize'),
            '#description' => $this->t('Randomize the rotation angle for each image. The angle specified above is used as a maximum.'),
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
        if (!$form_state->isValueEmpty('bgcolor') && !Color::validateHex($form_state->getValue('bgcolor'))) {
            $form_state->setErrorByName('bgcolor', $this->t('Background color must be a hexadecimal color value.'));
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
        parent::submitConfigurationForm($form, $form_state);
        $this->configuration['degrees'] = $form_state->getValue('degrees');
        $this->configuration['bgcolor'] = $form_state->getValue('bgcolor');
        $this->configuration['random'] = $form_state->getValue('random');
    }

}