<?php
// $Id: views_cloud.module,v 1.9 2010/01/07 20:40:06 quicksketch Exp $

/**
 * @file
 * Provide a tag cloud style for views data.
 */

/**
 * Implementation of hook_views_api.
 * Notifies the Views module that we're compatible with a particular API revision.
 */
function views_cloud_views_api() {
  return array('api' => 2);
}

/**
 * Display a view as a cloud.
 */
function template_preprocess_views_cloud_style(&$vars) {
  drupal_add_css(drupal_get_path('module', 'views_cloud') . '/views_cloud.css');

  $view = $vars['view'];

  $result = $vars['rows'];
  $vars['rows'] = array();

  $handler = $view->style_plugin;
  $weight_field = $view->style_plugin->options['weight_field'];
  $hide = $view->style_plugin->options['hide_weight_field'];
  $fields = &$view->field;

  // A quick error check. If no weight field is set, do not display anything.
  if (empty($weight_field) || !isset($fields[$weight_field])) {
    drupal_set_message(t('The cloud style could not be shown because a weight field is not set.'), 'error');
    return;
  }

  $weight_field_alias = $fields[$weight_field]->field_alias;

  $min = PHP_INT_MAX;
  $max = -PHP_INT_MAX;
  foreach ($result as $row) {
    $cur = intval($row->{$weight_field_alias});
    if ($min > $cur) {
      $min = $cur;
    }
    if ($max < $cur) {
      $max = $cur;
    }
  }

  foreach ($fields as $field => $column) {
    foreach ($result as $num => $row) {
      if ((!$hide || ($field != $weight_field)) &&
          !empty($fields[$field]) && empty($fields[$field]->options['exclude'])) {
        $field_output = $fields[$field]->theme($row);
        $vars['rows'][$num]['output'] .= $field_output;
      }
    }
  }

  $sizes = $view->style_plugin->options['sizes'];
  $algorithm = $view->style_plugin->options['algorithm'];
  foreach ($vars['rows'] as $num => $row) {
    $vars['rows'][$num]['cloud_size'] = views_cloud_size_helper($result[$num]->{$weight_field_alias}, $min, $max, $sizes, $algorithm);
    $vars['rows'][$num] = (object)$vars['rows'][$num];
  }

  $vars['font_size'] = empty($view->style_plugin->options['font_size']) ? NULL : $view->style_plugin->options['font_size'];

  if (!empty($view->style_plugin->options['randomize'])) {
    shuffle($vars['rows']);
  }
}


/**
 * Display a summary view as a cloud.
 */
function template_preprocess_views_cloud_summary_style(&$vars) {
  drupal_add_css(drupal_get_path('module', 'views_cloud') . '/views_cloud.css');

  $view     = $vars['view'];
  $argument = $view->argument[$view->build_info['summary_level']];

  $url_options = array();

  if (!empty($view->exposed_raw_input)) {
    $url_options['query'] = $view->exposed_raw_input;
  }
  
  // First we take a quick pass through to find the ceiling and floor
  $min = PHP_INT_MAX;
  $max = -PHP_INT_MAX;
  foreach ($vars['rows'] as $id => $row) {
    $vars['rows'][$id]->link = $argument->summary_name($row);
    $args = $view->args;
    $args[$argument->position] = $argument->summary_argument($row);

    $vars['rows'][$id]->url = url($view->get_url($args), $url_options);
    $vars['rows'][$id]->count = intval($row->{$argument->count_alias});
    
    if (empty($vars['rows'][$id]->link)) {
      unset($vars['rows'][$id]);
      continue;
    }
  
    $cur = intval($row->{$argument->count_alias});
    if ($min > $cur) {
      $min = $cur;
    }
    if ($max < $cur) {
      $max = $cur;
    }
  }

  $sizes = $view->style_plugin->options['sizes'];
  $algorithm = $view->style_plugin->options['algorithm'];
  foreach ($vars['rows'] as $id => $row) {
    $vars['rows'][$id]->cloud_size = views_cloud_size_helper($vars['rows'][$id]->count, $min, $max, $sizes, $algorithm);
  }

  $vars['font_size'] = empty($view->style_plugin->options['font_size']) ? NULL : $view->style_plugin->options['font_size'];

  if (!empty($view->style_plugin->options['randomize'])) {
    shuffle($vars['rows']);
  }
}

/**
 * Algorithm for calculating relative size.
 */
function views_cloud_size_helper($value, $min, $max, $sizes = 7, $algorithm = 'log') {
  if ($min == $max) return 1;

  if ($algorithm == 'linear') {
    $range = ($sizes - 1) / ($max - $min);
    $value = ($value - $min) * $range;
    return (intval($value + 1));
  }
  else {
    $value = log($value == 0 ? ++$value : $value);
    $min = log($min == 0 ? ++$min : $min);
    $max = log($max);
    $range = ($sizes - 1) / ($max - $min);
    $value = ($value - $min) * $range;
    return (intval($value + 1));
  }
}