<?php

/**
 * @file
 * Additional actions for imagecache processing.
 *
 * Exposes some of the simpler PHP 'imagefilter' actions (colorshift,
 * brightness, negative)
 * -  A transparency masker for merging with backgrounds.
 * -  A pseudo - file conversion feature.
 *
 * Compatible with the 2008 revision (imagecache 2)
 *
 * @author dan http://coders.co.nz
 * @author sydneyshan http://enigmadigital.net.au
 */

// During devel, caching is pointless. Flush it
//imagecache_action_definitions(TRUE);

if (! function_exists('imagecache_actions_calculate_relative_position') ) {
  module_load_include('inc', 'imagecache_actions', 'utility');
}
module_load_include('inc', 'imagecache_actions', 'utility-color');


// @todo There doesn't seem to be a way to specify a file in hook_image_effect_info
// so placing this here for the time being.
module_load_include('inc', 'imagecache_coloractions', 'transparency');

/**
 * hook_image_effect_info()
 *
 * Return the descriptions for the supported actions.
 */
function imagecache_coloractions_image_effect_info() {
  $effects = array();

  $effects['coloractions_colorshift'] = array(
    'label' => t('Color Shift'),
    'help' => t('Adjust image colors.'),
    'effect callback' => 'coloractions_colorshift_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'coloractions_colorshift_form',
    'summary theme' => 'coloractions_colorshift_summary',
  );

  $effects['imagecache_coloroverlay'] = array(
    'label' => t('Color Overlay'),
    'help' => t('Apply a color tint to an image (retaining blacks and whites).'),
    'effect callback' => 'coloractions_coloroverlay_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'coloractions_coloroverlay_form',
    'summary theme' => 'coloractions_coloroverlay_summary',
  );

  $effects['coloractions_brightness'] = array(
    'label' => t('Brightness'),
    'help' => t('Adjust image brightness.'),
    'effect callback' => 'coloractions_brightness_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'coloractions_brightness_form',
    'summary theme' => 'coloractions_brightness_summary',
  );

  $effects['coloractions_inverse'] = array(
    'label' => t('Negative Image'),
    'help' => t('Invert colors and brightness.'),
    'effect callback' => 'coloractions_inverse_image',
    'dimensions passthrough' => TRUE,
  );

  // @todo Convert may need a little more work.
  $effects['coloractions_convert'] = array(
    'label' => t('Change file format'),
    'help' => t('Choose to save the image as a different filetype.'),
    'effect callback' => 'coloractions_convert_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'coloractions_convert_form',
    'summary theme' => 'coloractions_convert_summary',
  );

  $effects['imagecache_alpha'] = array(
    'label' => t('Alpha Transparency'),
    'help' => t('Adjust transparency.'),
    'effect callback' => 'imagecache_alpha_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'imagecache_alpha_form',
    'summary theme' => 'coloractions_alpha_summary',
  );

  $effects['coloractions_posterize'] = array(
    'label' => t('Posterize'),
    'help' => t('Reduce the image to a limited number of color levels per channel.'),
    'effect callback' => 'coloractions_posterize_image',
    'dimensions passthrough' => TRUE,
    'form callback' => 'coloractions_posterize_form',
    'summary theme' => 'coloractions_posterize_summary',
  );

  return $effects;
}

/**
 * hook_theme()
 */
function imagecache_coloractions_theme() {
  return array(
    'coloractions_colorshift_summary' => array(
      'variables' => array('data' => NULL),
    ),
    'coloractions_coloroverlay_summary' => array(
      'variables' => array('data' => NULL),
    ),
    'coloractions_alpha_summary' => array(
      'variables' => array('data' => NULL),
    ),
    'coloractions_brightness_summary' => array(
      'variables' => array('data' => NULL),
    ),
    'coloractions_convert_summary' => array(
      'variables' => array('data' => NULL),
    ),
    'coloractions_posterize_summary' => array(
      'variables' => array('data' => NULL),
    ),
  );
}

/**
 * Implementation of imagecache_hook_form()
 *
 * Settings for colorshift actions.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function coloractions_colorshift_form($action) {
  $defaults = array(
    'RGB' => array(
      'HEX' => '#FF0000',
    ),
  );
  $action = array_merge($defaults, (array) $action);
  $form = array('#theme' => 'imagecache_rgb_form');
  $form['RGB'] = imagecache_rgb_form($action['RGB']);
  $form['note'] = array('#value' => t("<p>
    Note that colorshift is a mathematical filter that doesn't always
    have the expected result.
    To shift an image precisely TO a target color,
    desaturate (greyscale) it before colorizing.
    The hue (color wheel) is the <em>direction</em> the
    existing colors are shifted. The tone (inner box) is the amount.
    Keep the tone half-way up the left site of the color box
    for best results.
  </p>"));
  return $form;
}


/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_coloractions_colorshift_summary($variables) {
  return theme_imagecacheactions_rgb($variables['data']);
}


/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 *
 * Just converts and passes the vals to the all-purpose 'filter' action
 */
function coloractions_colorshift_image($image, $data = array()) {
  // convert color from hex (as it is stored in the UI)
  if ($data['RGB']['HEX'] && $deduced = imagecache_actions_hex2rgba($data['RGB']['HEX'])) {
    $data['RGB'] = array_merge($data['RGB'], $deduced);
  }
  return image_toolkit_invoke('colorshift', $image, array($data));
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_gd_colorshift($image, $data = array()) {
  $RGB = $data['RGB'];
  if (!function_exists('imagefilter')) {
    module_load_include('inc', 'imagecache_actions', 'imagefilter');
  }
  return imagefilter($image->resource, 4, $RGB['red'], $RGB['green'], $RGB['blue']);
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_imagemagick_colorshift($image, $data = array()) {
  $RGB = $data['RGB'];
  $image->ops[] = "-fill rgb" . escapeshellcmd('(') . "{$RGB['red']},{$RGB['green']},{$RGB['blue']}" . escapeshellcmd(')') . " -colorize 50" . escapeshellcmd('%');
  return TRUE;
}


/**
 * Implementation of imagecache_hook_form()
 *
 * Settings for coloroverlay actions.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function coloractions_coloroverlay_form($action) {
  $defaults = array(
    'RGB' => array(
      'HEX' => '#E2DB6A',
    ),
  );
  $action = array_merge($defaults, (array) $action);
  $form = array('#theme' => 'imagecache_rgb_form');
  $form['RGB'] = imagecache_rgb_form($action['RGB']);
  $form['note'] = array('#value' => t("<p>
    Note that color overlay is a mathematical filter that doesn't always
    have the expected result.
    To shift an image precisely TO a target color,
    desaturate (greyscale) it before colorizing.
    The hue (color wheel) is the <em>direction</em> the
    existing colors are shifted. The tone (inner box) is the amount.
    Keep the tone half-way up the left site of the color box
    for best results.
    </p>"));
  return $form;
}


/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_coloractions_coloroverlay_summary($variables) {
  return theme_imagecacheactions_rgb($variables['data']);
}


/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 *
 * Just converts and passes the vals to the all-purpose 'filter' action
 */
function coloractions_coloroverlay_image($image, $data = array()) {
  // convert color from hex (as it is stored in the UI)
  if ($data['RGB']['HEX'] && $deduced = imagecache_actions_hex2rgba($data['RGB']['HEX'])) {
    $data['RGB'] = array_merge($data['RGB'], $deduced);
  }
  return image_toolkit_invoke('coloroverlay', $image, array($data));
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_gd_coloroverlay($image, $data = array()) {
  $RGB = $data['RGB'];

  $w = $image->info['width'];
  $h = $image->info['height'];

  for($y=0;$y<$h;$y++) {
    for($x=0;$x<$w;$x++) {
      $rgb = imagecolorat($image->resource, $x, $y);
      $source = imagecolorsforindex($image->resource, $rgb);

      if($source['red'] <= 128){
        $final_r = (2 * $source['red'] * $RGB['red'])/256;
      }else{
        $final_r = 255 - (((255 - (2 * ($source['red'] - 128))) * (255 - $RGB['red']))/256);
      }
      if($source['green'] <= 128){
        $final_g = (2 * $source['green'] * $RGB['green'])/256;
      }else{
        $final_g = 255 - (((255 - (2 * ($source['green'] - 128))) * (255 - $RGB['green']))/256);
      }
      if($source['blue'] <= 128){
        $final_b = (2 * $source['blue'] * $RGB['blue'])/256;
      }else{
        $final_b = 255 - (((255 - (2 * ($source['blue'] - 128))) * (255 - $RGB['blue']))/256);
      }
      $final_colour = imagecolorallocatealpha($image->resource, $final_r, $final_g, $final_b, $source['alpha']);
      imagesetpixel($image->resource, $x, $y, $final_colour);
    }
  }

  return TRUE;
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_imagemagick_coloroverlay($image, $data = array()) {
  $RGB = $data['RGB'];
  $image->ops[] = escapeshellcmd('(') . " +clone +matte -fill rgb" . escapeshellcmd('(') . "{$RGB['red']},{$RGB['green']},{$RGB['blue']}" . escapeshellcmd(')') . " -colorize 100" . escapeshellcmd('%') . " +clone +swap -compose overlay -composite " . escapeshellcmd(')') . " -compose SrcIn -composite";
  return TRUE;
}


/**
 * Implementation of imagecache_hook_form()
 *
 * Settings for colorshift actions.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function coloractions_brightness_form($action) {
  $default = array('filter_arg1' => '100');
  $action = array_merge($default, (array) $action);
  $form = array();
  $form['help'] = array('#value' => t("The brightness effect seldom looks good on its own, but can be useful to wash out an image before making it transparent - eg for a watermark."));
  $form['filter_arg1'] = array(
    '#type' => 'textfield',
    '#title' => t('Brightness'),
    '#description' => t('-255 - +255'),
    '#default_value' => $action['filter_arg1'],
    '#size' => 3,
  );
  return $form;
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function coloractions_brightness_image($image, $data = array()) {
  return image_toolkit_invoke('brightness', $image, array($data));
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_gd_brightness($image, $data = array()) {
  if (!function_exists('imagefilter')) {
    module_load_include('inc', 'imagecache_actions', 'imagefilter');  }
  return imagefilter($image->resource, 2, $data['filter_arg1']);
}
/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_imagemagick_brightness($image, $data = array()) {
  $image->ops[] = "-modulate " . (int)(100 + ( $data['filter_arg1'] / 128 * 100 ));
  return TRUE;
}

/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_coloractions_brightness_summary($variables) {
  return t("Adjust") . " : " . $variables['data']['filter_arg1'];
}


/**
 * Implementation of imagecache_hook_form()
 *
 * No settings.
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function coloractions_inverse_form($action) {
  $form = array();
  return $form;
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function coloractions_inverse_image($image, $data = array()) {
  return image_toolkit_invoke('inverse', $image, array($data));
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_gd_inverse($image, $data = array()) {
  if (!function_exists('imagefilter')) {
    module_load_include('inc', 'imagecache_actions', 'imagefilter');
  }
  return imagefilter($image->resource, 0);
}
/**
 * Implementation of hook_{toolkit}_{effect}()
 */
function image_imagemagick_inverse(&$image, $data = array()) {
  // TODO
  return FALSE;
}

/**
 * Implementation of imagecache_hook_form()
 *
 * @param $action array of settings for this action
 * @return a form definition
 */
function coloractions_convert_form($action) {
  $form = array(
    'help' => array(
      '#markup' => t("If you've been using transparencies in the process, the result may get saved as a PNG (as the image was treated as a one in in-between processes). If this is not desired (file sizes may get too big) you should use this process to force a flatten action before saving. "),
    ),
    'help2' => array(
      '#markup' => t("For technical reasons, changing the file format within imagecache does <em>not</em> change the filename suffix. A png may be saved as a *.jpg or vice versa. This may confuse some browsers and image software, but most of them have no trouble. "),
    ),
    'format' => array(
      '#title' => t("File format"),
      '#type' => 'select',
      '#default_value' => isset($action['format']) ? $action['format'] : 'image/png',
      '#options' => coloractions_file_formats(),
    ),
    'quality' => array(
      '#type' => 'textfield',
      '#title' => t('Quality'),
      '#description' => t('Override the default image quality. Works for Imagemagick only. Ranges from 0 to 100. For jpg, higher values mean better image quality but bigger files. For png it is a combination of compression and filter'),
      '#size' => 10,
      '#maxlength' => 3,
      '#default_value' => isset($action['quality']) ? $action['quality'] : '75',
      '#field_suffix' => '%',
    ),
  );
  return $form;
}

/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_coloractions_convert_summary($variables) {
  $data = $variables['data'];
  $formats = coloractions_file_formats();
  if ($formats[$data['format']] == 'jpg') {
    return t('Convert to: @format, quality: @quality%', array(
    '@format' => $formats[$data['format']],
    '@quality' => $data['quality']
    ));
  }
  else {
    return t("Convert to") .": ". $formats[$data['format']];
  }
}

/**
 * Implementation of hook_image()
 *
 * Process the imagecache action on the passed image
 */
function coloractions_convert_image($image, $data = array()) {
  $formats = coloractions_file_formats();
  $image->info['mime_type'] = $data['format'];
  $image->info['extension'] = $formats[$data['format']];
  image_toolkit_invoke('convert_image', $image, array($data));
  return TRUE;
}

/**
 * Implementation of hook_{toolkit}_{effect}()
 *
 * image_toolkit_invoke will exit with an error when no implementation is
 * provided for the active toolkit so provide an empty operation for the GD
 * tookit
 */
function image_gd_convert_image($image, $data) {
  return TRUE;
}

/**
 * Implements hook_{toolkit}_{effect}().
 *
 * Converting the image format with imagemagick is done by prepending the output
 * format to the target file separated by a colon (:). This is done with
 * hook_imagemagick_arguments_alter(), see below.
 */
function image_imagemagick_convert_image($image, $data) {
  $image->ops['output_format'] = $image->info['extension'];
  $image->ops['custom_quality_value'] = (int) $data['quality'];
  return TRUE;
}

/**
 * Implements hook_imagemagick_arguments_alter.
 *
 * This hook moves a change in output format from the args (action list) to the
 * destination format setting within the context.
 */
function imagecache_coloractions_imagemagick_arguments_alter(&$args, &$context) {
  if (isset($args['output_format'])) {
    $context['destination_format'] = $args['output_format'];
    unset($args['output_format']);
  }
  if (isset($args['custom_quality_value'])) {
    $args['quality'] = sprintf('-quality %d', $args['custom_quality_value']);
    unset($args['custom_quality_value']);
  }
}

/**
 * Mini mime-type list
 */
function coloractions_file_formats() {
  return array('image/jpeg' => 'jpg', 'image/gif' => 'gif', 'image/png' => 'png');
}

/**
 * Implementation of theme_hook() for imagecache_ui.module
 */
function theme_coloractions_posterize_summary($variables) {
  return t(': Reduce to @colors color levels per channel', array('@colors' => $variables['data']['colors']));
}

function coloractions_posterize_image(&$image, $data) {
  if (!image_toolkit_invoke('posterize', $image, array($data['colors']))) {
    watchdog('image_posterize', 'Image posterize failed using the %toolkit toolkit on %path (%mimetype, %dimensions)', array(
      '%toolkit' => $image->toolkit,
      '%path' => $image->source,
      '%mimetype' => $image->info['mime_type'],
      '%dimensions' => $image->info['height'] . 'x' . $image->info['height'],
    ), WATCHDOG_ERROR);
    return FALSE;
  }
  return TRUE;
}

function coloractions_posterize_form($data) {
  $form = array();

  $form['colors'] = array(
    '#type' => 'textfield',
    '#title' => t('Color levels per channel'),
    '#default_value' => isset($data['colors']) ? $data['colors'] : '',
    '#required' => TRUE,
    '#size' => 10,
    '#element_validate' => array('image_effect_integer_validate'),
    '#allow_negative' => FALSE,
    '#description' => t('Number of unique values per color channel to reduce this image to. The transparency channel is left unchanged. This effect can be used to reduce file size on png images.'),
  );

  return $form;
}

/**
 * Posterize action for GD.
 *
 * @see http://www.qtcentre.org/threads/36385-Posterizes-an-image-with-results-identical-to-Gimp-s-Posterize-command?p=167712#post167712
 */
function image_gd_posterize(stdClass $image, $colors) {
  // Value step for colors per channel.
  $round_to = 255 / ($colors - 1);

  for ($x = imagesx($image->resource); $x--; ) {
    for ($y = imagesy($image->resource); $y--; ) {
      $rgb = imagecolorat($image->resource, $x, $y);

      // Use bitmasks to extract numbers we want, faster equivalent to imagecolorsforindex().
      $a = $rgb >> 24 & 255; // Alpha
      $r = $rgb >> 16 & 255; // Red
      $g = $rgb >> 8  & 255; // Green
      $b = $rgb       & 255; // Blue

      // (int) (value + 0.5) faster equivalent to round() and already an int.
      $new_r = (int) (((int) ($r / $round_to + 0.5)) * $round_to  + 0.5);
      $new_g = (int) (((int) ($g / $round_to + 0.5)) * $round_to  + 0.5);
      $new_b = (int) (((int) ($b / $round_to + 0.5)) * $round_to  + 0.5);

      // Faster equivalent to imagecolorallocatealpha().
      $color_combined = ($a << 24) | ($new_r << 16) | ($new_g << 8) | $new_b;
      imagesetpixel($image->resource, $x, $y, $color_combined);
    }
  }

  return TRUE;
}

/**
 * Posterize action for ImageMagick.
 */
function image_imagemagick_posterize(stdClass $image, $colors) {
  // In newer versions of ImageMagick dithering has no effect on posterize.
  // Turn dithering off on older versions of ImageMagick for consistency.
  $image->ops[] = ' +dither -posterize ' . (int) $colors;
  return TRUE;
}