<?php
/**
 * @file
 * Code for the Search Krumo module.
 *
 * This module was written by:
 * Bram ten Hove (bramth), bram.ten.hove@goalgorilla.com
 * Daniel Beeke
 */

/**
 * A function that adds backtracing capability to Devels dpm().
 *
 * With this function we can copy the variable that is called in sdpm(), so we
 * can make life easier for developers.
 *
 * @param arbitrary $input
 *   An arbitrary value to output.
 * @param string $name
 *   (optional) Name for identifying the output.
 */
function sdpm($input, $name = NULL) {
  // Get the label that we should prepend to each 'Get path' button.
  $label = search_krumo_inspect();
  drupal_add_js(array('searchKrumo' => array('var' => array($label))), 'setting');

  // Route it to the dpm() function provided by the Devel module.
  dpm($input, $name);
}

/**
 * Implements hook_init().
 */
function search_krumo_init() {
  // We add search_krumo javascript on every page.
  // If it's not necessary it is removed in hook_js_alter.
  add_search_krumo();
}

/**
 * Implements hook_js_alter().
 *
 * With this function we check if there is a krumo present. If there is we can
 * leave our own Javascript, otherwise our Javascript is not needed either.
 */
function search_krumo_js_alter(&$javascript) {
  // This is the path for the Devel krumo Javascript.
  $devel_js_path = drupal_get_path('module', 'devel') . '/devel_krumo_path.js';

  // When Devel krumo Javascript is not present, remove Search Krumo Javascript.
  if (!isset($javascript[$devel_js_path])) {
    unset($javascript[drupal_get_path('module', 'search_krumo') . '/search_krumo.search.js']);
    unset($javascript[drupal_get_path('module', 'search_krumo') . '/search_krumo.trail.js']);
  }
}

/**
 * Add required Javascript files for Search Krumo.
 *
 * We need this to add the JavaScript every time that we display a krumo.
 */
function add_search_krumo() {
  drupal_add_js(drupal_get_path('module', 'search_krumo') . '/search_krumo.search.js');
  drupal_add_js(drupal_get_path('module', 'search_krumo') . '/search_krumo.trail.js');
}

/**
 * Function that returns the variable name that is the input for sdpm().
 *
 * @return string
 *   Either the real variable name or the default variable name $var.
 */
function search_krumo_inspect() {
  // Start a backtrace.
  $backtrace = debug_backtrace();

  // Continue on if we can read the the backtrace files.
  if (is_readable($backtrace[1]['file'])) {
    $src = file($backtrace[1]['file']);
    $line = $src[$backtrace[1]['line'] - 1];

    // Match the function call and the last closing bracket.
    preg_match('#sdpm\((.+)\)#', $line, $match);

    // If we have a match we return it.
    if (isset($match[1])) {
      return $match[1];
    }
    else {
      // Else we return the default variable name.
      $label = '$var';
    }
  }
  else {
    // Else we return the default variable name.
    return '$var';
  }
}