<?php

// $Id: cck_field_perms.module,v 1.3.2.24 2007/05/10 21:14:03 arthuregg Exp $

/*
 * This module adds the ability to restrict some fields in a CCK node
 * to certian user roles based on create, updated, and view. Note that
 * when this module is enabled, you must positively grant view access
 * if you want users to have view access.
 *
 */

/* ********************************************* */
/* Drupal functions */
/* ********************************************* */


/**
 * Implementation of hook_help().
 */
function cck_field_perms_help($section) {
  switch ($section) {
    case 'admin/help#cck_field_perms':
      return t('<p>Gives the option of limited access to CCK data for user roles.</p>');
      break;
  }
}

/**
 * Implentation of hook menu
 */
function cck_field_perms_menu($may_cache){
  $items = array();
  $items[] = array(
    'path' => 'admin/settings/cck_field_perms',
    'title' => t('CCK Field Permissions'),
    'description' => t('Restrict create, update and view access on specific CCK fields.'),
    'callback' => 'cck_field_perms_admin_settings',
    'access' => user_access('administer cck field permissions'),
    'type' => MENU_NORMAL_ITEM,
  );
  return $items;
}


/**
 * Impementation of hook perms
 */
function cck_field_perms_perm(){
  $perm_list[] = "administer cck field permissions";
  $field_perms = unserialize(variable_get('cfp_values', null));
  if ($field_perms) {
    foreach ($field_perms as $type_name => $fields) {
      foreach ($fields as $field_name => $value) {
        if ($value) {
          foreach (cck_field_perms_verbs() as $verb){
            $perm_list[] = _cfp_content_to_readable($type_name, $field_name, $verb);
          }
        }
      }
    }
  }
  return $perm_list;
}

/**
 * Implementation of hook_nodeapi
 * removes fields if a user does not have perms to view it
 */
function cck_field_perms_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  if ($op == 'view') {
    $type = $node->type;
    if ($types = variable_get('cfp_types', null)) {
      if ($types[$type]) {
        $disallowed_fields = unserialize(variable_get('cfp_values', null));
        if ($disallowed_fields) {
          foreach ($disallowed_fields[$type] as $disallowed_field => $value ) {
            if ($value == 0) {continue; }
              if (!(user_access(_cfp_content_to_readable($type, $disallowed_field, "view")))) {
                $node->$disallowed_field['#access'] = false;
                $node->content[$disallowed_field]['#access'] = false;
            }
          }
        }
      }
    }
  }
}


/**
 * Implemenation of hook form_alter
 */
function cck_field_perms_form_alter($form_id, &$form){
  if ($form['#id'] != 'node-form') return;
  // detect if we're editing or creating
  if ($form['#node']->nid) {
    global $user;
    $verb = $form['uid']['#value'] == $user->uid ?  "edit own" : "edit";
  }
  else {
    $verb = "create";
  }
  $form =  _cfp_form_helper($form_id, $form, $verb);
}


/* ********************************************* */
/* CFP functions */
/* ********************************************* */

/**
 * Defines the CRUD.
 */
function cck_field_perms_verbs(){
  return array('create', 'edit', 'edit own', 'view',);
}

/**
 * perms helper
 * converts drupal content names to human readable names
 */
function _cfp_content_to_readable ($content_type, $field_name, $verb){
  static $content_types;
  if (! ($content_types)) {$content_types = content_types();}

  // support fieldgroup content
  if(strstr($field_name, "group_")){
    $output = $verb . " " . $content_types[$content_type]['name'] . " " . $field_name;
  }
  else {
    $output = $verb . " " . $content_types[$content_type]['name'] . " " . $content_types[$content_type]['fields'][$field_name]['widget']['label'];
  }
  return $output;
}

/**
 * gets list of form groups from a form and removes
 * field groups if the user does not have permission
 * helper function for the form alter
 *
 */
function _cfp_form_group_fieldset_helper(&$form, $disallowed, $type, $verb){
  if (module_exists("fieldgroup")){
    foreach($form as $name => $item){
      if($disallowed[$name]){
        if (!(user_access(_cfp_content_to_readable($type, $name, $verb)))){
          // Do not unset the form, else any existing values will be
          // overwritten with the field default values, instead, disable
          // them in _cfp_form_helper()
          //unset($form[$name]);
        }
      }

      // check this item to see if it is a group
      // if group, recurse to check for sub groups and or fieldsets
      if (strstr($name, "group")){
        if(is_array($form[$name])){
          _cfp_form_group_fieldset_helper($form[$name], $disallowed, $type, $verb);
        }
      }
    }
  }
}


/**
 * helper function to unset form values
 *
 * @form is drupal form
 * @verb is create or update
 * @return is the modified drupal form
 *
 */
function _cfp_form_helper($form_id, &$form, $verb){
  //content_video_node_form
  $types = variable_get('cfp_types', null);

  if ($types) {
    foreach ($types as $type) {
      if ($form_id == $type . "_node_form") {
        $disallowed_fields = unserialize(variable_get('cfp_values', null));
        if ($disallowed_fields) {
          // disable fieldgroups
          _cfp_form_group_fieldset_helper($form, $disallowed_fields[$type], $type, $verb);

          foreach ($disallowed_fields[$type] as $disallowed_field => $disallowable) {
            if ($disallowable) {
              if (!user_access(_cfp_content_to_readable($type, $disallowed_field, $verb))) {
                // This is a hack. With CCK we don't know where the actual form
                // element may be stored, so we manually check all known loctions
                // and set the #disabled flag when we find the location.
                if ($form[$disallowed_field]['#type']) {
                  $form[$disallowed_field]['#disabled'] = TRUE;
                }
                elseif ($form[$disallowed_field]['key']['#type']) {
                  $form[$disallowed_field]['key']['#disabled'] = TRUE;
                }
                elseif ($form[$disallowed_field]['uids']['#type']) {
                  $form[$disallowed_field]['uids']['#disabled'] = TRUE;
                }
                else {
                  // potentially unhandled nested form here
                }
              }
              // else access allowed, leave form unchanged
            }
          }
        }
      }
    }
  }

  return $form;
}

/* ************************ */
/* ADMIN Functions */
/* ************************ */


/**
 * page for the admin settings form
 * use this instead of standard settings for b/c we
 * serialize all the data into one variable
 */
function cck_field_perms_admin_settings(){
  $output = drupal_get_form('cck_field_perms_admin_settings_form');
  return $output;
}

/**
 * creates the admin form
 */
function cck_field_perms_admin_settings_form(){
  $form['field_perms'] = array(
    '#type' => 'fieldset',
    '#title' => t('Enable field permissions on content types.'),
    '#description' => t("This module allows an administrator to restrict CCK fields to some roles. " .
                        "Once you have enabled a content type, select which fields you'd like to restrict. " .
                        "Then, go to " . l("admin/user/access", "admin/user/access"). " to allow user roles acces to that field. " .
                        "Please note: you must grant view access for a field once you enable this field to be permissions controlled. " .
                        "If you do not do this, no users will be able to view the field. "),
  );

  $types = content_types();

  foreach ($types as $key => $value) {
    $options[$key] = $value['name'];
  }
  $enabled_types = variable_get('cfp_types', null);
  $form['field_perms']['cfp_types'] = array(
   '#type' => 'checkboxes',
   '#title' => t('Content types'),
   '#description' => t('Select content types for which you wish to enable permissions.'),
   '#options' => $options,
   '#default_value' =>  $enabled_types,
  );

  $the_settings = unserialize(variable_get('cfp_values', ''));

  if ($enabled_types ) {
    foreach ($enabled_types as $enabled_type) {
      if ($enabled_type) {
        $form['field_fields'][$enabled_type] = array(
          '#type' => 'fieldset',
          '#title' => $types[$enabled_type]['name'] . " content fields",
        );

        if ($types[$enabled_type]['fields']) {

          // deal with grouped content
          _cfp_group_form_fields($form, $types[$enabled_type]['fields'], $enabled_type, $the_settings);

          foreach ($types[$enabled_type]['fields'] as $field) {
            $field_perms[$field['field_name']] = $field['widget']['label'];

            $form['field_fields'][$enabled_type]["{$enabled_type}_{$field['field_name']}"]= array(
              '#type' => 'checkbox',
              '#title' => $field['widget']['label'],
              '#description' => t(''),
              '#default_value' => $the_settings[$enabled_type][$field['field_name']],
              '#description' => t("Enable permissions on this field."),
            );
          }
        }
      }
    }
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save')
  );
  return $form;
}

/**
 * fetches the list of fields contained within a group
 * returns fieldset form of check boxes to handle content
 */
function _cfp_group_form_fields(&$form, &$fields, $type, $values) {
  if (module_exists("fieldgroup")) {
    $groups = fieldgroup_groups($type);
    foreach ($groups as $group_name => $data) {
      $form['field_fields'][$type][$group_name . "_fields"] = array(
        '#type' => 'fieldset',
        '#title' => $data['label'] . " field group",
      );
      $form['field_fields'][$type][$group_name . "_fields"][$type ."_" .$group_name] = array(
        '#type' => 'checkbox',
        '#title' => $data['label'],
        '#description' => t("Checking this box will hide this complete field group"),
        '#default_value' => $values[$type][$group_name],
      );

      foreach ($data['fields'] as $afield) {
        $form['field_fields'][$type][$group_name . "_fields"][$type . "_" .$afield['field_name']] = array(
          '#type' => 'checkbox',
          '#title' => $afield['label'] ." field",
          '#description' => t("Checking this box will hide this field "),
          '#default_value' => $values[$type][$afield['field_name']],

        );
        //remove this field from the list of fields that we have
        unset($fields[$afield['field_name']]);
      }
    }
  }
}


/**
 * save the incoming values
 */
function cck_field_perms_admin_settings_form_submit($form_id, $form_values){

  // @ TODO figure out why the hell it is neccessary to do this
  if ($form_values['cfp_types'][0]) { unset($form_values['cfp_types'][0]); }
  if ($form_values['cfp_types'][1]) { unset($form_values['cfp_types'][1]); }

  variable_set('cfp_types', $form_values['cfp_types']);

  foreach ($form_values as $key => $value) {
    if (strstr($key, "_field_") ) {
      $type = substr($key, 0, strpos($key, "_field"));
      $field = substr($key, strpos($key, "field"));
      $stored_values[$type][$field] = $value;
    }
    if (strstr($key, "_group_") ) {
      $type = substr($key, 0, strpos($key, "_group"));
      $field = substr($key, strpos($key, "group"));
      $stored_values[$type][$field] = $value;
    }
  }
  variable_set('cfp_values', serialize($stored_values));
  drupal_set_message("Remember to update ". l("admin/user/access", "admin/user/access") ." after you've changed permissions.");
}