<?php
// $Id: imageapi.module,v 1.10 2008-04-15 14:28:14 dopry Exp $

/**
 * @file
 *
 * An ImageAPI supporting additional image plugins as modules. 
 * Images are treated as objects, and images are not written per
 * manipulation as Drupal's core image handling works.
 * 
 * 
 * imageapi image api workflow... 
 * $image = imageapi_image_open($path) to get an image object for $path...
 * image_X($image, $arg1, $arg2)  to manipulate image object...
 * imageapi_image_close($image) to overwrite original image.
 * 
 */

define('IMAGEAPI_MINIMUM_PHP', '5.2');
function imageapi_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/imageapi',
      'title' => t('ImageAPI'),
      'description' => t('Configure ImageAPI.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('imageapi_settings'),
    );
  }
  else {
    $toolkits = imageapi_get_available_toolkits();
    if ($toolkits) {
      $items[] = array(
        'path' => 'admin/settings/imageapi/list',
        'title' => 'List',
        'type' => MENU_DEFAULT_LOCAL_TASK,
        'weight' => -1,
      );
      $items[] = array(
        'path' => 'admin/settings/imageapi/config',
        'title' => 'Configure',
        'type' => MENU_LOCAL_TASK,
        'callback' => 'drupal_get_form',
        'callback arguments' => array(imageapi_default_toolkit() .'_settings_form'),
      );
      foreach ($toolkits as $module => $info) {
        $items[] = array(
          'path' => 'admin/settings/imageapi/config/'. $module,
          'title' => $info['name'],
          'callback' => 'drupal_get_form',
          'callback arguments' => array($module .'_settings_form'),
          'type' => $module == imageapi_default_toolkit() ? MENU_DEFAULT_LOCAL_TASK : MENU_LOCAL_TASK,
        );
      }
    }
  }
  return $items;
}

function imageapi_settings() {
  $form = array();

  $toolkits = imageapi_get_available_toolkits();

  switch (count($toolkits)) {
    case 0:
      $form['imageapi_toolkits']['#value'] = t('There are no image toolkit modules enabled. Toolkit modules can be enabled from the <a href="!admin-build-modules">module configuration page</a>.', array('!admin-build-modules' => url('admin/build/modules')));
      return $form;
    
    case 1:
      $toolkit = key($toolkits);
      // The variable needs to be manually set. Otherwise, if a user has two 
      // toolkits and disables the selected one they won't be able to select the 
      // remaing toolkit.
      variable_set('imageapi_image_toolkit', $toolkit);
      $form['imageapi_image_toolkit']['#value'] = t('The %toolkit module is the only enabled image toolkit. Drupal will use it for resizing, cropping and other image manipulations.', array('%toolkit' => $toolkits[$toolkit]['name']));
      return $form;
            
    default:
      $options = array();
      foreach ($toolkits as $module => $info) {
        $options[$module] = $info['name'];
      }
      $form['imageapi_image_toolkit'] = array(
        '#type' => 'radios',
        '#title' => t('Select a default image processing toolkit'),
        '#default_value' => imageapi_default_toolkit(),
        '#options' => $options,
        '#description' => t('This setting lets you choose which toolkit Drupal uses resizing, cropping and other image manipulations.'),
      );
  }

  return system_settings_form($form);
}

/**
 *  Implementation of hook_requirements().
 */
function imageapi_requirements($phase) {
  $requirements = array();
  // Ensure translations don't break at install time
  $t = get_t();

  if (version_compare(phpversion(), IMAGEAPI_MINIMUM_PHP) < 0) {
    $requirements['imageapi_php'] = array(
      'title' => $t('ImageAPI PHP'),
      'description' => $t('ImageAPI requires at least PHP %version.', array('%version' => IMAGEAPI_MINIMUM_PHP)),
      'severity' => REQUIREMENT_ERROR
    );
  }
  
  return $requirements;
}

/**
 * Return a list of available toolkits.
 *
 * @return 
 *   An array of the enabled image toolkit modules. The module name is the key
 *   and the value is a sub-array with the module's 'name' and 'description'.  
 */
function imageapi_get_available_toolkits() {
  static $toolkits;
 
  if (!isset($toolkits)) {
    $toolkits = array();
    foreach (module_implements('imageapi_toolkit', TRUE) as $module) {
      $info = _module_parse_info_file(drupal_get_path('module', $module) .'/'. $module .'.info');
      $toolkits[$module] = array('name' => $info['name'], 'description' => $info['description']);
    }
  }
  
  return $toolkits;
}

/**
 * Retrieve the name of the currently used toolkit.
 *
 * @return 
 *   String containing the name of the toolkit, or FALSE if none is available.
 */
function imageapi_default_toolkit() {
  $toolkit = variable_get('imageapi_image_toolkit', 'imageapi_gd');
  // Verify that the image toolkit is available.
  if (isset($toolkit) && module_exists($toolkit)) {
    return $toolkit;
  }
  return FALSE;
}

/**
 * Scales an image to the exact width and height given. Achieves the
 * target aspect ratio by cropping the original image equally on both
 * sides, or equally on the top and bottom.  This function is, for
 * example, useful to create uniform sized avatars from larger images.
 *
 * The resulting image always has the exact target dimensions.
 *
 * @param $image
 *   An ImageAPI Image object.
 * @param $width
 *   The target width in pixels.
 * @param $height
 *   The target height in pixels.
 * @return
 *   Modified ImageAPI Image object.
 */
function imageapi_image_scale_and_crop(&$image, $width, $height) {
  $scale = max($width / $image->info['width'], $height / $image->info['height']);
  $x = round(($image->info['width'] * $scale - $width) / 2);
  $y = round(($image->info['height'] * $scale - $height) / 2);
 
  if (imageapi_image_resize($image, $image->info['width'] * $scale, $image->info['height'] * $scale)) {
    return imageapi_image_crop($image, $x, $y, $width, $height);
  }
  return FALSE;
}

/**
 * Scales an image to the given width and height while maintaining aspect
 * ratio.
 *
 * The resulting image can be smaller for one or both target dimensions.
 *
 * @param $image
 *   An ImageAPI Image object.
 * @param $width
 *   The target width in pixels.
 * @param $height
 *   The target height in pixels.
 * @param $upscale
 *   Allow upscaling.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_scale(&$image, $width, $height, $upscale = FALSE) {
  // Don't scale up.
  if (!$upscale && $width >= $image->info['width'] && $height >= $image->info['height']) {
    return TRUE;
  }

  $aspect = $image->info['height'] / $image->info['width'];
  if ($aspect < $height / $width) {
    $height = (int) round($width * $aspect);
  }
  else {
    $width = (int) round($height / $aspect);
  }
  
  return call_user_func($image->toolkit .'_image_resize', $image, $width, $height);
}
 
/**
 * Resize an image to the given dimensions (ignoring aspect ratio).
 *
 * @param $source        The filepath of the source image.
 * @param $source
 *   The filepath of the source image.
 * @param $destination
 *   The file path of the destination image.
 * @param $width
 *   The target width in pixels.
 * @param $height
 *   The target height in pixels.
 * @param $toolkit
 *   An optional override of the default image toolkit.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_resize(&$image, $width, $height) {
  return call_user_func($image->toolkit .'_image_resize', $image, $width, $height);
}
 
/**
 * Rotate an image by the given number of degrees.
 *
 * @param $source
 *   The filepath of the source image.
 * @param $destination
 *   The file path of the destination image.
 * @param $degrees
 *   The number of (clockwise) degrees to rotate the image.
 * @param $bg_color
 *   An hexidecimal integer specifying the background color to use for the 
 *   uncovered area of the image after the rotation. E.g. 0x000000 for black, 
 *   0xff00ff for magenta, and 0xffffff for white.
 * @param $toolkit
 *   An optional override of the default image toolkit.
 * @return
 *   TRUE or FALSE, based on success.
 */
function imageapi_image_rotate(&$image, $degrees, $bgcolor = 0x000000) {
  return call_user_func($image->toolkit .'_image_rotate', $image, $degrees, $bgcolor);
}
 
/**
 * Crop an image to the rectangle specified by the given rectangle.
 *
 * @param $image
 *   An imageapi image object.
 * @param $x
 *   The top left co-ordinate of the crop area (x axis value).
 * @param $y
 *   The top left co-ordinate of the crop area (y axis value).
 * @param $width
 *   The target width in pixels.
 * @param $height
 *   The target height in pixels.
 * @return 
 *   modifed image object.
 */
function imageapi_image_crop(&$image, $x, $y, $width, $height) {
  return call_user_func($image->toolkit .'_image_crop', $image, $x, $y, $width, $height);
}
 

function imageapi_image_desaturate(&$image) {
  return call_user_func($image->toolkit .'_image_desaturate', $image);
}

function imageapi_image_open($file, $toolkit = FALSE) {
  if (!$toolkit) {
    $toolkit = imageapi_default_toolkit();
  }
  if ($toolkit) {
    $image = new StdClass();
    $image->source = $file;
    $image->info = image_get_info($file);
    $image->toolkit = $toolkit;
    if ($image = call_user_func($image->toolkit.'_image_open', $image)) {
      return $image;
    }
  }
  watchdog('imageapi', t('ImageAPI failed to open %file with %toolkit', array('%file' => $file, '%toolkit' => $toolkit)), WATCHDOG_WARNING);
  return FALSE;
}

/**
 * Write an image to a file. 
 *
 * @param $image 
 *   imageAPI image object.
 *
 * @param $destination
 *   destination path where image should be saved. If it is empty the original image will
 *   be over written.
 */
function imageapi_image_close($image, $destination = '') {
  if (empty($destination)) {
    $destination = $image->source;
  }
  if ($return = call_user_func($image->toolkit .'_image_close', $image, $destination)) {
    if (@chmod($destination, 0775)) {
      return $return;
    } 
    watchdog('imageapi', t('Could not set permissons on destination file: %file', array('%file' => $destination)));
  }
  return FALSE;
}