<?php
/**
 * @file
 * D3 module file for creating visualizations with d3.js.
 *
 * Sponsored by http://www.freeflowdigital.com
 */

/**
 * Implements hook_theme().
 */
function d3_theme() {

  foreach (libraries_info() as $path => $library) {
    // Call this function to get all fields - i.e. library path.
    $library = libraries_load($path);
    // If a template was specified in the .info file or hook_libraries_info.
    if (isset($library['template'])) {
      // Change d3.[library name] to d3_[library name] for a theme key.
      $theme_key = str_replace('.', '_', $library['machine name']);
      $themes[$theme_key] = array(
        'template' => $library['template'],
        'path' => $library['library path'],
      );
    }
  }

  $themes['d3'] = array(
    'variables' => array(),
    'template' => 'd3',
  );

  $themes['d3_graphapi'] = array(
    'variables' => array(
      'graph' => NULL,
      'config' => NULL,
    ),
  );

  return $themes;
}

/**
 * Implements hook_preprocess_d3() for d3.tpl.php.
 */
function d3_preprocess_d3(&$variables) {

  // Let drupal_attributes render this.
  $variables['classes_array'][] = $variables['type'];
  $variables['attributes_array']['id'] = array($variables['vis_id']);

  $library = isset($variables['library']) ? $variables['library'] : FALSE;

  // Let's look for a template file in the library definition.
  if (isset($library['template'])) {
    $variables['theme_hook_suggestion'] = isset($library['library name']) ? $library['library name'] : str_replace('.', '_', $library['machine name']);
  }
}

/**
 * Implements hook_libraries_info_file_paths().
 */
function d3_libraries_info_file_paths() {

  // Get all library directories.
  $libraries = libraries_get_libraries();

  $paths = array();
  // Output an array of paths to check for.
  foreach ($libraries as $path) {
    $paths[] = $path;
  }

  // Load the directory where the d3 example libraries are.
  $example_path = drupal_get_path('module', 'd3') . '/libraries/';

  // Add these to the search directories for libraries.
  foreach (d3_default_libraries() as $example) {
    $paths[] = $example_path . $example;
  }

  return $paths;
}

/**
 * Implements hook_libraries_info_alter().
 */
function d3_libraries_info_alter(&$libraries) {
  // Automatically add in the d3.drupal dependency so that each
  // d3.library doesn't have to.
  foreach (d3_get_libraries() as $library_name => $library) {
    $libraries[$library_name]['dependencies'][] = 'd3.drupal';
  }
  // By default, the libraries module only checks the libraries folders.
  // We need to add this module's libraries path to the library info.
  $path = drupal_get_path('module', 'd3') . '/libraries/';
  foreach (d3_default_libraries() as $library_name) {
    // Change library path to path/to/module/d3/libraries
    $libraries[$library_name]['library path'] = $path . $library_name;
  }
}

/**
 * Implements hook_libraries_info().
 */
function d3_libraries_info() {

  $libraries = array();

  // Drupal ext adds behaviors and d3 global object.
  $libraries['d3.drupal'] = array(
    'name' => 'D3 Drupal ext',
    'vendor url' => 'http://drupal.org/sandbox/asherry/1477334',
    'files' => array(
      'js' => array(
        'd3.js',
      ),
    ),
    'path' => 'js',
    'library path' => drupal_get_path('module', 'd3'),
    'dependencies' => array('d3'),
    'version' => '1',
  );

  // Path to library, (if installed).
  $path = libraries_get_path('d3');

  if ($path) {
    $files = array();
    // In the repository the files might me named d3.js and d3.min.js.
    $files += file_scan_directory($path, '/d3.js|d3.min.js/');
    // They could also have the version # in the file name.
    $files += file_scan_directory($path, '/d3.v[0-9](.min)?.js/');

    // If we don't have any files we shouldn't add the library at all.
    // This will fire drupal error and direct the user to reports.
    if (count($files) == 0) {
      return $libraries;
    }

    // This will be the default file.
    // @TODO: Add this to d3 settings so you can choose.
    $file = array_shift($files);
    $version = 0;

    // If this is a repository, there should be a package file. We can filter
    // out the version number.
    $package = file_exists($path . '/package.json') ? file_get_contents($path . '/package.json') : FALSE;
    if ($package) {
      preg_match('/\"version\"\:\ \"([0-9\.]*)\"/', $package, $version_matches);
      if (isset($version_matches[1])) {
        $version = $version_matches[1];
      }
    }
    // If this is from the zip file, we should be able to get the version
    // from the actual file itself.
    if (strpos($file->filename, '.v')) {
      preg_match('/\.v([0-9])/', $file->filename, $version_matches);
      if (isset($version_matches[1])) {
        $version = $version_matches[1];
      }
    }

    $libraries['d3'] = array(
      'name' => 'D3',
      'vendor url' => 'http://d3js.org/',
      'download url' => 'http://d3js.org/',
      'files' => array(
        'js' => array(
          $file->filename,
        ),
      ),
      'version' => $version,
    );
  }

  return $libraries;
}

/**
 * Helper callback to return all sample libraries located inside this module.
 */
function d3_default_libraries() {
  return array(
    'd3.columnchart',
    'd3.stackedcolumnchart',
    'd3.extend',
    'd3.forcedirected',
    'd3.module_dependencies',
    'd3.linegraph',
    'd3.tooltip',
    'd3.barchart',
    'd3.piechart',
  );
}

/**
 * D3's main API callback.
 *
 * @param array $vis
 *   The chart data
 *
 * @return string
 *   Rendered chart html
 */
function d3_draw($vis) {

  // Type is required for correct processing.
  $type = isset($vis['type']) ? strtolower($vis['type']) : NULL;

  if (!$type) {
    drupal_set_message(t('No chart type specified'));
    return '';
  }

  // Form library name - convention is going to be d3.[library].
  $library_name = 'd3.' . $type;

  // Check for library instance / definition.
  if (libraries_detect($library_name)) {
    $vis['library'] = libraries_load($library_name);
    $vis['library']['library name'] = str_replace('.', '_', $library_name);
    // Enforce lowercase change.
    $vis['type'] = $type;
    // Store as vis_id because key ['id'] will get overridden.
    $vis['vis_id'] = $vis['id'];

    // Now add to the behaviors to execute on page load.
    $js = array(
      'd3' => array(
        'inventory' => array($vis['id'] => $vis),
      ),
    );
    drupal_add_js($js, 'setting');

    // Renders the html - .tpl.php if specified or default d3.tpl.php.
    return theme('d3', $vis);

  }
  else {
    drupal_set_message(t('Invalid chart type %type and/or library %library_name is not installed', array(
      '%type' => $type,
      '%library_name' => $library_name,
    )));
    return '';
  }
}

/**
 * Provides an array of d3 libraries.
 *
 * D3 libraries are going to have a prefix of d3., see README.txt
 * for information on creating a custom d3 library.
 */
function d3_get_libraries() {

  static $d3_libraries;

  if ($d3_libraries) {
    return $d3_libraries;
  }
  // Returns all libraries in the default folders.
  $libraries = libraries_info();

  foreach ($libraries as $library) {
    $library_name = $library['machine name'];
    // Filter out any other non-d3 library. All d3 libraries should have
    // the prefix "d3.".
    if (strpos($library_name, 'd3.') === FALSE) {
      continue;
    }
    // Do not list these default extension libraries.
    if (in_array($library_name, array('d3.extend', 'd3.tooltip', 'd3.drupal'))) {
      continue;
    }

    $d3_libraries[$library_name] = $library;
    $d3_libraries[$library_name]['js callback'] = str_replace('d3.', '', $library_name);
  }

  return $d3_libraries;
}
/**
 * Implements hook_graphapi_formats().
 */
function d3_graphapi_formats() {
  return array(
    'd3' => t('D3'),
  );
}

/**
 * Implements hook_graphapi_settings_form().
 */
function d3_graphapi_settings_form($values) {

  $engine = 'd3';
  $form[$engine] = array(
    '#type' => 'fieldset',
    '#title' => 'D3 settings',
  );

  $options = array();
  foreach (d3_get_libraries() as $library) {
    $options[$library['js callback']] = $library['name'];
  }
  $form[$engine]['library'] = array(
    '#title' => 'Default library',
    '#description' => t('Use this d3 library as the default to render graphapi visualizations'),
    '#type' => 'select',
    '#options' => $options,
    '#default_value' => $values['library'],
  );

  return $form;

}

/**
 * Converts $graph data array two arrays for links and nodes.
 *
 * @param array $graph
 *   Associative array of nodes with link information and data.
 *
 * @return array
 *   Links and nodes.
 */
function _d3_graphapi_format_graph_data($graph) {
  $data = array();
  $indices = array();
  $index = 0;

  foreach ($graph as $id => $node) {
    $indices[$id] = $index;
    $index++;
  }

  // Add in edges.
  foreach ($graph as $id => $node) {
    $index = $indices[$id];
    $data['nodes'][$index] = array(
      'name' => $node['data']['title'],
      'group' => isset($node['data']['group']) ? $node['data']['group'] : 1,
      'data' => $node['data'],
    );
    if (count($node['edges']) > 0) {
      foreach ($node['edges'] as $edge => $edge_data) {
        $value = isset($edge_data['data']['value']) ? (int) $edge_data['data']['value'] : NULL;

        $data['links'][] = array(
          'data' => isset($edge_data['data']) ? $edge_data['data'] : array(),
          'source' => $index,
          'target' => $indices[$edge],
          // TODO: This is hard coded, it could be dynamic.
          'value' => $value,
        );
      }
    }
  }

  return $data;
}

/**
 * Displays the visualization for graphapi's selected library.
 */
function theme_d3_graphapi($vars) {
  if (empty($vars['graph'])) {
    return '';
  }
  $default_library = variable_get('d3_graphapi_default_library', 'forcedirected');
  $library = empty($vars['config']['library']) ? $default_library : $vars['config']['library']; 
  $graph = _d3_graphapi_format_graph_data($vars['graph']);
  $chart = array(
    'id' => $vars['config']['id'],
    'type' => $library,
    'links' => $graph['links'],
    'nodes' => $graph['nodes'],
    'config' => $vars['config'],
  );
  return d3_draw($chart);
}

/**
 * Implements hook_graphapi_default_settings().
 *
 * We reuse the default settings from thejit_forcedirected_default_settings.
 *
 * @see thejit_forcedirected_default_settings()
 * @see views_object::option_definition()
 */
function d3_graphapi_default_settings() {
  return array(
    'd3' => array(
      'library' => array('default' => 'd3.forcedirected'),
    ),
  );
}