<?php
// $Id: sparkline.module,v 1.8 2009-03-16 18:31:11 chris Exp $

/**
 * @file
 * A Drupal wrapper for the PHP Sparklines library.  Allows other modules to
 * generate sparklines, and provides a filter for users to embed them in posts.
 */

function sparkline_menu() {
  $items = array();
  $items['admin/settings/sparkling'] = array(
    'title' => 'Sparklines',
    'description' => 'Configure the cache location and other settings for sparkline rendering.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('sparkline_admin_settings'),
    'access callback' => 'user_access',
    'access arguments' => array('administer sparklines'),
  );
  return $items;
}


/**
 * Implementation of hook_perm(). Just used to control access to the admin screen.
 */
function sparkline_perm() {
  return array('administer sparklines');
}

/**
 * Implementation of hook_theme().  Registers theme functions.
 */
function sparkline_theme() {
  return array(
    'sparkline' => array('arguments' => array('element')),
    'sparkline_element' => array('arguments' => array()),
  );
}


/**
 * Implementation of hook_cron(). This clears out any 'non-permanent' cached sparklines.
 */
function sparkline_cron() {
  _sparkline_flush_cache();
}

/**
 * Implementation of hook_help().
 */
function sparkline_help($path, $arg) {
  switch ($path) {
    case 'admin/modules#description':
      // This description is shown in the listing at admin/modules.
      return t('Lets users sparkline graphs using simple tags.');
  }
}

/**
 * Form API callback to validate the sparkline admin settings form.
 */
function sparkline_admin_settings_validate($form, &$form_state) {
  if (!is_dir($form_state['values']['sparkline_path'])) {
    form_set_error('sparkline_path', t('The directory %dir does not exist.', array('%dir' => $form_state['values']['sparkline_path'])));
  }
  $cache_path = file_directory_path() .'/'. $form_state['values']['sparkline_cache'];
  file_check_directory($cache_path, FILE_CREATE_DIRECTORY, 'sparkline_cache');
}

/**
 * Render the form for the sparkline settings page.
 *
 * @return
 *   The system settings form for the sparklines module.
 */
function sparkline_admin_settings() {
  $form = array();
  $form['sparkline_path'] = array(
    '#type' => 'textfield',
    '#title' => t('Sparkline PHP path'),
    '#required' => TRUE,
    '#description' => t('The Sparklines PHP library (http://sparkline.org) is required. Download it and copy it to the sparkline module directory.'),
    '#default_value' => variable_get('sparkline_path', drupal_get_path('module', 'sparkline') .'/sparkline-php-0.2'),
  );
  
  $form['sparkline_cache'] = array(
    '#type' => 'textfield',
    '#title' => t('The name of the sparkline cache directory, inside of the normal Drupal files directory'),
    '#required' => TRUE,
    '#default_value' => variable_get('sparkline_cache', 'sparkline'),
  );

  return system_settings_form($form);
}

/**
 * Implementation of hook_filter_tips().
 */
function sparkline_filter_tips($delta, $format, $long = FALSE) {
   return t('Sparkline filter: [sparkline style=line|bar|winloss height=15 12,3,-2,39,23,2,......]');
}

/**
 * Implementation of hook_filter().
 */
function sparkline_filter($op, $delta = 0, $format = -1, $text = '') {
  if ($op == 'list') {
    return array(0 => t('Sparkline filter'));
  }

  switch ($delta) {
    case 0:
      switch ($op) {
        case 'description':
          return t('Lets writers use the [sparkline] tag to embed tiny visual graphs in their posts.');

        case 'prepare':
          return $text;

        case 'process':
          return _sparkline_process_text($text);
      }
      break;
  }
}

/**
 * Process text from the sparkline input filter.
 *
 * @param $text
 *   The text to process.
 * @return
 *   The rendered sparklines included in the text.
 */
function _sparkline_process_text($text) {
  $pattern = "/\[sparkline[ +]?(?:(?:style=)?(bar|line|winloss))?[ +]?(?:height=([0-9]*))?[ +]?(?:width=([0-9]*))?[ +]?(?:min=([0-9]*))?[ +]?(?:max=([0-9]*))? ([-0-9,]*)\]/";
  if (preg_match_all($pattern, $text, $matches)) {
    foreach ($matches[0] as $key => $value) {
      $style = empty($matches[1][$key]) ? 'bar' : $matches[1][$key];     
      $tmp = sparkline_elements(); 
      $sparkline = $tmp['sparkline_'. $style];

      if (!empty($matches[2][$key])) {
        $sparkline['#height'] = $matches[2][$key];
      }
      if (!empty($matches[3][$key])) {
        $sparkline['#width'] = $matches[3][$key];
      }
      $sparkline['#min'] = empty($matches[4][$key]) ? NULL : $matches[4][$key];
      $sparkline['#max'] = empty($matches[5][$key]) ? NULL : $matches[5][$key];
      $sparkline['#data'] = explode(',', $matches[6][$key]);
      
      // We do this so that filtered sparklines (which rarely change and whose urls are cached)
      // don't get blown out of the cache folder at cron-time.
      $sparkline['#do_not_flush'] = TRUE;
      
      $replacements[$key] = theme('sparkline', $sparkline);
    }
    $text = str_replace($matches[0], $replacements, $text);
  }
  return $text;
}

/**
 * Implementation of hook_elements().
 */
function sparkline_elements() {
  $elements['sparkline_line'] = _sparkline_defaults(array(
    '#style' => 'line',
    '#flag_points' => TRUE,
    '#min' => NULL,
    '#max' => NULL,
  ));

  $elements['sparkline_bar'] = _sparkline_defaults(array(
    '#style' => 'bar',
    '#bar_width' => 2,
    '#bar_gap' => 1,
    '#min' => NULL,
    '#max' => NULL,
  ));
  
  $elements['sparkline_winloss'] = _sparkline_defaults(array(
    '#style' => 'winloss',
    '#bar_width' => 2,
    '#bar_gap' => 1,
  ));
  
  return $elements;
}

/**
 * Return the default values for a sparkline element.
 *
 * @param $element
 *   The element to add default settings to.
 * 
 * @return
 *   The element with the default settings.
 */
function _sparkline_defaults($element = array()) {
  $element['#width'] = 'auto';
  $element['#height'] = 15;
  $element['#positive_color'] = 'black';
  $element['#negative_color'] = 'red';
  $element['#background_color'] = 'white';
  $element['#data'] = array();
  $element['#theme'] = 'sparkline_element';
  $element['#do_not_flush'] = FALSE;
  return $element;
}

/**
  * Theme a sparkline element. Lines, bars, and win/loss sparklines can be
  * rendered.
  *
  * @param $element
  *   The sparkline element to render.
  *
  * @return unknown_type
  *   The themed sparkline element HTML.
  */
function theme_sparkline($element) {    
  $api_path =  variable_get('sparkline_path', drupal_get_path('module', 'sparkline') .'/sparkline-php-0.2') .'/lib';

  switch ($element['#style']) {
    case 'line':
      $path = _sparkline_generate_path($element);
      if (!file_exists($path)) {
        require_once($api_path .'/Sparkline_Line.php');
        $sparkline = new Sparkline_Line(FALSE);
        $min = 0;
        $max = 0;
        foreach ($element['#data'] as $i => $value) {
          $min = ($element['#data'][$min] > $value) ? $i : $min;
          $max = ($element['#data'][$max] < $value) ? $i : $max;
        
          $sparkline->SetData($i, $value);
        }
        if ($element['#width'] == 'auto') {
          $element['#width'] = min(count($element['#data']) * 3, 200);
        }
      
        if (!empty($element['#min'])) {
          $sparkline->SetYMin($element['#min']);
        }
        if (!empty($element['#max'])) {
          $sparkline->SetYMax($element['#max']);
        }
        if ($element['#flag_points']) {
          $keys = array_keys($element['#data']);
          $end = $keys[count($keys) - 1];
          $sparkline->SetFeaturePoint($end - 1, $element['#data'][$end], 'grey', 2);
          $sparkline->SetFeaturePoint($min, $element['#data'][$min], $element['#negative_color'], 2);
          $sparkline->SetFeaturePoint($max, $element['#data'][$max ], $element['#positive_color'], 2);
        }

        $sparkline->RenderResampled($element['#width'], $element['#height']);
        $sparkline->Output($path);
      }
      break;

    case 'bar':
      $path = _sparkline_generate_path($element);
      if (!file_exists($path)) {
        require_once($api_path .'/Sparkline_Bar.php');
        $sparkline = new Sparkline_Bar(FALSE);
      
        $sparkline->SetBarWidth($element['#bar_width']);
        $sparkline->SetBarSpacing($element['#bar_gap']);

        foreach ($element['#data'] as $i => $value) {
          $sparkline->SetData($i, $value, ($value < 0 ? $element['#negative_color'] : $element['#positive_color']), FALSE);
        }
        if (!empty($element['#min'])) {
          $sparkline->SetYMin($element['#min']);
        }
        if (!empty($element['#max'])) {
          $sparkline->SetYMax($element['#max']);
        }
        $sparkline->Render($element['#height']);
        $sparkline->Output($path);
      }
      break;

    case 'winloss':
      $path = _sparkline_generate_path($element);
      if (!file_exists($path)) {
        require_once($api_path .'/Sparkline_Bar.php');
        $sparkline = new Sparkline_Bar(FALSE);
      
        $sparkline->SetBarWidth($element['#bar_width']);
        $sparkline->SetBarSpacing($element['#bar_gap']);

        foreach ($element['#data'] as $i => $value) {
          if ($value < 1) {
            $sparkline->SetData($i, -1, $element['#negative_color'], FALSE);
          }
          else {
            $sparkline->SetData($i, 1, $element['#positive_color'], FALSE);
          }
        }
        if (!empty($element['#min'])) {
          $sparkline->SetYMin($element['#min']);
        }
        $sparkline->Render($element['#height']);
        $sparkline->Output($path);
      }
      break;
  }

  if (isset($path)) {
    return theme('image', $path, NULL, NULL, array('class' => 'sparkline'));
  }
}

/**
 * Theme a sparkline form element.
 *
 * @param $element
 *   The form element to theme.
 *
 * @return
 *  The themed HTML for the sparkline element.
 */
function theme_sparkline_element($element) {
  return theme('form_element', $element, theme('sparkline', $element));
}

/**
 * Generate a path to a sparkline.
 *
 * @param $sparkline
 *   The sparkline element to look up.
 *
 * @return
 *   The path to the sparkline.
 */
function _sparkline_generate_path($sparkline) {
  // If the directory doesn't exist, create it.
  $cache_dir = file_directory_path() .'/'. variable_get('sparkline_cache', 'sparkline');
  if (!file_exists($cache_dir)) {
    mkdir(file_directory_path() .'/'. variable_get('sparkline_cache', 'sparkline'));
  }
  if (!empty($sparkline['#filename'])) {
    return file_directory_path() .'/'. variable_get('sparkline_cache', 'sparkline') .'/'. $sparkline['#filename'];
  }
  else {
    return file_directory_path() .'/'. variable_get('sparkline_cache', 'sparkline') .'/'. ($element['#do_not_flush'] ? '-' : '') . md5(serialize($sparkline)) .'.png';
  }
}

/**
 * Flush the sparkline image cache.
 */
function _sparkline_flush_cache() {
  $listing = file_directory_path() .'/'. variable_get('sparkline_cache', 'sparkline') ."/{!-}*.png";
  foreach (glob($listing) as $file) {
    if (is_file($file) === true) {
      @unlink($file);
    }
  }
}