<?php
// $Id: casetracker.module,v 1.123.2.33 2011/01/03 18:49:42 jmiccolis Exp $

/**
 * @file
 * Enables the handling of projects and their cases.
 */

/**
 * Implementation of hook_views_api().
 */
function casetracker_views_api() {
  return array('api' => 2);
}

/**
 * Implementation of hook_help().
 */
function casetracker_help($path, $arg) {
  switch ($path) {
    case 'admin/settings/casetracker/states':
      return '<p>'. t('Current Case Tracker case states are listed below.') .'</p>';
    case 'admin/settings/casetracker/states/add':
      return '<p>'. t('You may add a new case state below.') .'</p>';
    case 'admin/settings/casetracker/states/edit/'. arg(4):
      return '<p>'. t('You may edit an existing case state below.') .'</p>';
    case 'admin/settings/casetracker':
      return '<p>'. t('Configure the various Case Tracker options with these settings.') .'</p>';
  }
}

/**
 * Implementation of hook_perm().
 */
function casetracker_perm() {
  return array(
    'administer case tracker',
    'assign cases',    
  );
}

/**
 * Implementation of hook_menu().
 */
function casetracker_menu() {
  /* casetracker main settings */
  $items['admin/settings/casetracker'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('casetracker_settings'),
    'description' => 'Configure the various Case Tracker options with these settings.',
    'title' => 'Case Tracker',
    'type' => MENU_NORMAL_ITEM,
  );
  $items['admin/settings/casetracker/settings'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('casetracker_settings'),
    'title' => 'Settings',
    'weight' => -10,
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  /* casetracker state handling */
  $items['admin/settings/casetracker/states'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'casetracker_case_state_overview',
    'type' => MENU_LOCAL_TASK,
    'title' => 'Case states',
    'description' => 'Add, edit and delete Case States, Types and Priorities',
  );
  $items['admin/settings/casetracker/states/list'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'casetracker_case_state_overview',
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'title' => 'Overview',
    'weight' => -10,
    'description' => 'Add, edit and delete Case States, Types and Priorities',
  );
  $items['admin/settings/casetracker/states/add'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('casetracker_case_state_edit'),
    'title' => 'Add case state',
    'type' => MENU_LOCAL_TASK,
  );
  $items['admin/settings/casetracker/states/edit/%casetracker_case_state'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('casetracker_case_state_edit', 5),
    'title' => 'Edit case state',
    'type' => MENU_CALLBACK,
  );
  $items['admin/settings/casetracker/states/delete/%casetracker_case_state'] = array(
    'file' => 'casetracker_admin.inc',
    'access arguments' => array('administer case tracker'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('casetracker_case_state_confirm_delete', 5),
    'title' => 'Delete case state',
    'type' => MENU_CALLBACK,
  );
  /* casetracker autocomplete */
  $items['casetracker_autocomplete'] = array(
    'title' => 'Case Tracker autocomplete',
    'page callback' => 'casetracker_autocomplete',
    'access callback' => 'user_access',
    'access arguments' => array('assign cases'),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Implementation of hook_nodeapi().
 */
function casetracker_nodeapi(&$node, $op, $teaser = NULL, $page = NULL) {
  // CASES
  if (casetracker_is_case($node->type)) {
    switch ($op) {

      case 'delete':
        // delete case and its comments.
        $comment_results = db_query("SELECT cid FROM {comments} WHERE nid = %d", $node->nid);
        while ($comment_result = db_fetch_object($comment_results)) {
          db_query("DELETE FROM {casetracker_comment_status} WHERE cid = %d", $comment_result->cid);
        }
        db_query('DELETE FROM {casetracker_case} WHERE nid = %d', $node->nid);
        break;

      case 'presave':
        // $node->casetracker is an Array and we wanna it to be an object.
        $node->casetracker = (object) $node->casetracker;
        break;

      case 'insert':
        // cases: generate a case ID and send it along.
        $record = $node->casetracker;
        $record->assign_to = is_numeric($record->assign_to) ? $record->assign_to : casetracker_get_uid($record->assign_to);
        $record->nid = $node->nid;
        $record->vid = $node->vid;

        drupal_write_record('casetracker_case', $record);
        break;

      case 'load':
        $casetracker = db_fetch_object(db_query('SELECT pid, case_priority_id, case_type_id, assign_to, case_status_id FROM {casetracker_case} WHERE nid = %d AND vid = %d', $node->nid, $node->vid));
        if ($casetracker) {
          return array('casetracker' => $casetracker);
        }
        break;

      case 'update':
        $record = (object) $node->casetracker;
        $record->assign_to = is_numeric($record->assign_to) ? $record->assign_to : casetracker_get_uid($record->assign_to);
        $record->nid = $node->nid;
        $record->vid = $node->vid;

        $primary = $node->revision ? array('nid') : array('nid', 'vid');
        drupal_write_record('casetracker_case', $record, $primary);
        break;

      case 'view':
        // On preview the case will be an array, we want an object.
        if (isset($node->build_mode) && $node->build_mode == NODE_BUILD_PREVIEW) {
          $node->casetracker = (object)$node->casetracker;
        }

        // used in the breadcrumb and our theme function, mostly for nid and project number display.
        $project = node_load($node->casetracker->pid);

        if ($page) {
          $trail = array(
            l(t('Home'), NULL),
            l(t('Case Tracker'), 'admin/casetracker/projects'),
            l($project->title, "node/{$node->casetracker->pid}"),
            l(t('All cases'), "admin/casetracker/cases/{$node->casetracker->pid}/all"),
          );
          drupal_set_breadcrumb($trail);
        }

        $node->content['casetracker_case_summary'] = array(
          '#value' => theme('casetracker_case_summary', $node, $project),
          '#weight' => -10
        );
        break;

    }
  }
  // PROJECTS
  else if (casetracker_is_project($node->type)) {
    switch ($op) {

      case 'delete':
        // projects: delete all the cases under the project and all the comments under each case.
        $case_results = db_query("SELECT nid from {casetracker_case} WHERE pid = %d", $node->nid);
        while ($case_result = db_fetch_object($case_results)) {
          db_query("DELETE FROM {casetracker_case} WHERE nid = %d", $case_result->nid);
          $comment_results = db_query("SELECT cid FROM {comments} WHERE nid = %d", $case_result->nid);
          while ($comment_result = db_fetch_object($comment_results)) {
            db_query("DELETE FROM {casetracker_comment_status} WHERE cid = %d", $comment_result->cid);
          }
          node_delete($case_result->nid); // this'll handle comment deletion too.
        }
        break;

      case 'view':
        if ($page) {
          $trail = array(
            l(t('Home'), NULL),
            l(t('Case Tracker'), 'admin/casetracker/projects'),
          );
          drupal_set_breadcrumb($trail);
        }
      
        $node->content['casetracker_project_summary'] = array('#value' => theme('casetracker_project_summary', $node), '#weight' => -10);
        break;
    }
  }
}

/**
 * Implementation of hook_comment().
 */
function casetracker_comment(&$comment, $op) {
  // Load the node here anyway -- it is almost certainly static cached already.
  $node = is_array($comment) ? node_load($comment['nid']) : node_load($comment->nid);

  // Bail if this is not a casetracker node.
  if (!casetracker_is_case($node->type)) {
    return;
  }

  if ($op == 'insert' || $op == 'update') {
    $new = (object) $comment['casetracker'];
    $new->cid = $comment['cid'];
    $new->nid = $comment['nid'];
    $new->vid = $comment['revision_id'];
    $new->state = 1;
    $new->assign_to = casetracker_get_uid($new->assign_to);

    // Populate old state values from node
    $old = $node->casetracker;
    $old->cid = $comment['cid'];
    $old->state = 0;

    drupal_write_record('casetracker_case', $new, array('nid', 'vid'));
  }

  switch ($op) {
    case 'insert':
      drupal_write_record('casetracker_comment_status', $old);
      drupal_write_record('casetracker_comment_status', $new);
      break;
    case 'update':
      drupal_write_record('casetracker_comment_status', $old, array('cid', 'state'));
      drupal_write_record('casetracker_comment_status', $new, array('cid', 'state'));
      break;
    case 'delete':
      // @todo theoretically, if you delete a comment, we should reset all the values
      // to what they were before the comment was submitted. this doesn't happen yet.
      db_query("DELETE FROM {casetracker_comment_status} WHERE cid = %d", $comment->cid);
      break;
    case 'view':
      // If this is a preview we won't have a cid yet.
      if (empty($comment->cid)) {
        $case_data['new'] = (object)$comment->casetracker;
        $case_data['new']->assign_to = casetracker_get_uid($case_data['new']->assign_to);
        $case = node_load($comment->nid);
        $case_data['old'] = drupal_clone($case->casetracker);
      }
      else {
        $results = db_query("SELECT * FROM {casetracker_comment_status} WHERE cid = %d", $comment->cid);
        while ($result = db_fetch_object($results)) {
          $state = $result->state ? 'new' : 'old';
          $case_data[$state] = $result;
        }
      }
      $comment->comment = theme('casetracker_comment_changes', $case_data['old'], $case_data['new']) . $comment->comment;        
      break;
  }
}

/**
 * Implementation of hook_form_alter().
 */
function casetracker_form_alter(&$form, &$form_state, $form_id) {
  if (!empty($form['#node'])) {
    $node = $form['#node'];

    // Add case options to our basic case type.
    if (casetracker_is_case($node->type)) {
      $count = count(casetracker_project_options());
      if ($count == 0) {
        drupal_set_message(t('You must create a project before adding cases.'), 'error');
        return;
      }
      else {
        $default_project = null;
        if (!isset($form['#node']->nid) && is_numeric(arg(3))) {
          $default_project = arg(3);
        }
        casetracker_case_form_common($form, $default_project);
      }
    }
  }
}

/**
 * Implementation of hook_form_comment_form_alter().
 */
function casetracker_form_comment_form_alter(&$form, &$form_state) {
  $node = isset($form['nid']['#value']) ? node_load($form['nid']['#value']) : NULL;
  if (casetracker_is_case($node->type)) {
    $form['#node'] = $node;

    // add case options to the comment form.
    casetracker_case_form_common($form);

    // necessary for our casetracker_comment() callback.
    $form['revision_id'] = array('#type' => 'hidden', '#value' => $node->vid);
  }
}

/**
 * Common form elements for cases, generic enough for use either in
 * a full node display, or in comment displays and updating. Default
 * values are calculated based on an existing $form['nid']['#value'].
 *
 * @param $form
 *   A Forms API $form, as received from a hook_form_alter().
 * @param $default_project
 *   The project ID that should be pre-selected.
 * @return $form
 *   A modified Forms API $form.
 */
function casetracker_case_form_common(&$form, $default_project = NULL) {
  global $user;

  $node = $form['#node'];

  // On preview the case will be an array, we want an object.
  if (isset($node->build_mode) && $node->build_mode == NODE_BUILD_PREVIEW) {
    $node->casetracker = (object)$node->casetracker;
  }

  // project to set as the default is based on how the user got here.
 if (empty($default_project) && !empty($node->casetracker->pid)) {
    $default_project = $node->casetracker->pid;
  }

  $project_options = casetracker_project_options();

  $form['casetracker'] = array(
    '#type' => 'fieldset',
    '#title' => t('Case information'),
    '#weight' => -10,
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
    '#tree' => TRUE,
    '#theme' => 'casetracker_case_form_common',
  );

  // if there's no project ID from the URL, or more than one project,
  // we'll create a select menu for the user; otherwise, we'll save
  // the passed (or only) project ID into a hidden field.
  if (count($project_options) > 1) {
    $form['casetracker']['pid'] = array(
      '#title' => t('Project'),
      '#type' => 'select',
      '#default_value' => $default_project,
      '#options' => $project_options,
    );
  }
  else {
    $form['casetracker']['pid'] = array(
      '#type' => 'value', // default value, or the only the project ID in the project_options array.
      '#value' => !empty($default_project) ? $default_project : key($project_options),
    );
  }

  // Retrieve the assign_to default value.
  if (isset($node->casetracker->assign_to)) {
    $default_assign_to = is_numeric($node->casetracker->assign_to) ? casetracker_get_name($node->casetracker->assign_to) : $node->casetracker->assign_to;
  }
  else {
    $default_assign_to = casetracker_default_assign_to();
  }

  // Only show this element if the user has access.
  $form['casetracker']['assign_to'] = array(
    '#title' => t('Assign to'),
    '#required' => TRUE,
    '#access' => user_access('assign cases'),
  );

  // Use different widgets based on the potential assignees.
  $options = drupal_map_assoc(casetracker_user_options());
  $assign_to_widget = variable_get('casetracker_assign_to_widget', 'flexible');
  if (($assign_to_widget == 'flexible' && count($options) < 25) || $assign_to_widget == 'radios') {
    $form['casetracker']['assign_to']['#type'] = 'radios';
    $form['casetracker']['assign_to']['#options'] = $options;
  }
  else if (($assign_to_widget == 'flexible' && count($options) < 50) || $assign_to_widget == 'select') {
    $form['casetracker']['assign_to']['#type'] = 'select';
    $form['casetracker']['assign_to']['#options'] = $options;
  }
  else {
    $form['casetracker']['assign_to']['#type'] = 'textfield';
    $form['casetracker']['assign_to']['#autocomplete_path'] = 'casetracker_autocomplete';
    $form['casetracker']['assign_to']['#size'] = 12;
  }

  // Set the default value if it is valid.
  $form['casetracker']['assign_to']['#default_value'] = in_array($default_assign_to, $options, TRUE) ? $default_assign_to : NULL;

  $case_status_options = casetracker_realm_load('status');
  $default_status = !empty($node->casetracker->case_status_id) ? $node->casetracker->case_status_id : variable_get('casetracker_default_case_status', key($case_status_options));
  $form['casetracker']['case_status_id'] = array(
    '#type' => 'select',
    '#title' => t('Status'),
    '#options' => $case_status_options,
    '#default_value' => $default_status,
  );

  $case_priority_options = casetracker_realm_load('priority');
  $default_priority = !empty($node->casetracker->case_priority_id) ? $node->casetracker->case_priority_id : variable_get('casetracker_default_case_priority', key($case_priority_options));
    $form['casetracker']['case_priority_id'] = array(
    '#type' => 'select',
    '#title' => t('Priority'),
    '#options' => $case_priority_options,
    '#default_value' => $default_priority,
  );

  $case_type_options = casetracker_realm_load('type');
  $default_type = !empty($node->casetracker->case_type_id) ? $node->casetracker->case_type_id : variable_get('casetracker_default_case_type', key($case_type_options));
  $form['casetracker']['case_type_id'] = array(
    '#type' => 'select',
    '#title' => t('Type'),
    '#options' => $case_type_options,
    '#default_value' => $default_type,
  );

  return $form;
}

/**
* Implementation of hook_block
*/
function casetracker_block($op = 'list', $delta = 0, $edit = array()) {
  switch ($op) {
    case 'list':
      $blocks[0] = array(
        'info' => t('Jump to case'),
      );
      return $blocks;
    case 'configure':
       return array();
    case 'save':
        return;
    case 'view':
      switch ($delta) {
        case 0:
          if (user_access('access content')) {
            $block['subject'] = t('Jump to case');
            $block['content'] = drupal_get_form('casetracker_block_jump_to_case_number');
          }
          break;
      }
      return $block;
  }
}

/**
 * Form for "Jump to case number" block.
 */
function casetracker_block_jump_to_case_number() {
  $form = array();
  $form['case_number'] = array(
    '#maxlength' => 60, 
    '#required' => TRUE,
    '#size' => 15,
    '#title' => t('Case number'),
    '#type' => 'textfield',
    '#prefix' => '<div class="container-inline">',
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Go'),
    '#suffix' => '</div>',
  );
  return $form;
} 

/**
 * Submit function for our "Jump to case number" block.
 */
function casetracker_block_jump_to_case_number_submit($form, $form_state) {
  list($pid, $nid) = explode('-', $form_state['values']['case_number']);
  $case_nid = db_result(db_query("SELECT nid FROM {casetracker_case} WHERE pid = %d AND nid = %d", $pid, $nid));
  if (!$case_nid) {
    drupal_set_message(t('Your case number was not found.'), 'error');
    return;
  }
  drupal_goto('node/'. $case_nid);
}

/**
 * CASE STATE CRUD ====================================================
 */

/**
 * Returns information about the various case states and their options.
 * The number of parameters passed will determine the return value.
 *
 * @param $csid
 *   Optional; the state ID to return from the passed $realm.
 * @param $realm
 *   Optional; the name of the realm ('status', 'priority', or 'type').
 * @param $reset
 *   Optional; set to TRUE to reset the static cache.
 *
 * @return $values
 *   If only $realm is passed, you'll receive an array with the keys
 *   being the state ID and the values being their names. If a $csid
 *   is also passed, you'll receive just a string of the state name.
 *   If ONLY a $csid is passed, we'll return a list of 'name', 'realm'.
 */
function casetracker_case_state_load($csid = NULL, $realm = NULL, $reset = FALSE) {
  static $states_lookup;

  if (!$states_lookup || $reset) {
    $results = db_query("SELECT csid, case_state_name AS name, case_state_realm AS realm, weight 
                         FROM {casetracker_case_states} ORDER BY weight");
    $states_lookup = array();
    while ($row = db_fetch_object($results)) {
      $row->display = casetracker_tt("case_states:$row->csid:name", $row->name);
      $states_lookup[$row->realm][$row->csid] = $states_lookup['all'][$row->csid] = $row;
    }
  }

  if ($csid && $realm) {
    return $states_lookup['all'][$csid]->display;
  }
  elseif ($csid && !$realm) {
    return $states_lookup['all'][$csid];
  }
  elseif (!$csid && $realm) {
    $options = array(); // suitable for form api.
    if (!empty($states_lookup[$realm])) {
      foreach ($states_lookup[$realm] as $state) {
        $options[$state->csid] = $state->display;
      }
    }
    return $options;
  }
}

/**
 * Translate user defined string. Wrapper function for tt() if i18nstrings enabled.
 * 
 * The string id for case states will be: case:[realm]#[csid]:name
 * 
 * @param $name
 *   String id without 'casetracker', which will be prepended automatically
 */
function casetracker_tt($name, $string, $langcode = NULL) {
  return function_exists('i18nstrings') ? i18nstrings('casetracker:' . $name, $string, $langcode) : $string;
}

/**
 * Implementation of hook_locale().
 */
function casetracker_locale($op = 'groups', $group = NULL) {
  switch ($op) {
    case 'groups':
      return array('casetracker' => t('Case Tracker'));
    case 'info':
      $info['casetracker']['refresh callback'] = 'casetracker_locale_refresh';
      $info['casetracker']['format'] = FALSE;
      return $info;
  }
}

/**
 * Refresh locale strings.
 */
function casetracker_locale_refresh() {
  $results = db_query("SELECT csid, case_state_name AS name, case_state_realm AS realm FROM {casetracker_case_states}");
  while ($row = db_fetch_object($results)) {
    i18nstrings_update("casetracker:case_states:$row->csid:name", $row->name);
  }
  // Meaning it completed with no issues. @see i18nmenu_locale_refresh().
  return TRUE;
}

/**
 * Load states for a particular realm. Wrapper around casetracker_case_state_load()
 *
 * @param $realm
 *   Name of the realm ('status', 'priority', or 'type').
 *
 * @return
 *   array with the keys being the state ID and the values being their names.
 */
function casetracker_realm_load($realm) {
  return casetracker_case_state_load(null, $realm);
}

/**
 * Saves a case state.
 *
 * @param $case_state
 *   An array containing 'name' and 'realm' keys. If no 'csid'
 *   is passed, a new state is created, otherwise, we'll update
 *   the record that corresponds to that ID.
 */
function casetracker_case_state_save($case_state = NULL) {
  if (!$case_state['name'] || !$case_state['realm']) { 
    return NULL; 
  }
  // Need to collect information into another array since the db columns have different names : (
  $record = array(
    'case_state_name' => $case_state['name'],
    'case_state_realm' => $case_state['realm'],
    'weight' => $case_state['weight'],
  );
  if (isset($case_state['csid'])) {
    $record['csid'] = $case_state['csid']; 
    drupal_write_record('casetracker_case_states', $record, array('csid'));
  }
  else {
    drupal_write_record('casetracker_case_states', $record);
  }
  // Update translations
  if (function_exists('i18nstrings_update')) {
    i18nstrings_update('casetracker:case_states:'. $record['csid'] .':name', $case_state['name']);
  }
  return $result;
}

/**
 * Deletes a case state.
 *
 * @todo There is currently no attempt to do anything with cases which
 * have been assigned the $csid that is about to be deleted. We should
 * reset them to the default per our settings (and warn the user on our
 * confirmation page), or something else entirely.
 * 
 * @param $csid
 *   The case state ID to delete.
 */
function casetracker_case_state_delete($csid = NULL) {
  if (!empty($csid)) {
    db_query('DELETE FROM {casetracker_case_states} WHERE csid = %d', $csid);
  }
}

/**
 * COMMENT DISPLAY ====================================================
 */

/**
 * Retrieve autocomplete suggestions for assign to user options.
 *
 * @TODO: In order to get this down to 1 query and respect any custom
 * views selected for use as user option filters, we need to:
 * - Submit a patch to the Views user name filter/argument handler to support LIKE filtering.
 * - Ensure that the custom view uses this handler or add it if does not.
 * - Generate the query & result set using this modified View.
 */
function casetracker_autocomplete($string) {
  $matches = array();
  $options = casetracker_user_options();
  $result = db_query_range("SELECT name FROM {users} WHERE LOWER(name) LIKE LOWER('%s%%')", $string, 0, 10);
  while ($user = db_fetch_object($result)) {
    if (in_array($user->name, $options, TRUE)) {
      $matches[$user->name] = check_plain($user->name);
    }
  }

  // Special case for 'Unassigned'
  $unassigned = t('Unassigned');
  if (strpos(strtolower($unassigned), strtolower($string)) !== FALSE) {
    $matches[$unassigned] = $unassigned;
  }
  drupal_json($matches);
}

/**
 * Returns an query string needed in case of Organic Groups
 * providing preselected audience checkboxes for projects as groups (og)
 * 
 * @param   object  CT project
 * @return  string
 */
function _casetracker_get_og_query_string(&$project) {
  $querystring = array();
  // checking if project is group
  if ($project->type == 'group') {
    $querystring[] = 'gids[]='. $project->nid;
    //checking if group-project is part of another group
    if (isset($project->og_groups) 
      && is_array($project->og_groups) 
    ) {
      foreach ($project->og_groups as $group) {
        $querystring[] = 'gids[]='. $group;
      }
    }
  }
  //checking if project is part of a group
  elseif (isset($project->og_groups) 
    && is_array($project->og_groups) 
    && $project->type !== 'group'
  ) {
    foreach ($project->og_groups as $group) {
      $querystring[] = 'gids[]='. $group;
    }
  }
 
  return (0 < count($querystring))
      ? implode('&', $querystring)
      : NULL;
}

/**
 * THEME ==============================================================
 */

/**
 * Implementation of hook_theme
 */
function casetracker_theme() {
  return array(
    'casetracker_comment_changes' => array(),
    'casetracker_case_form_common' => array(),
    'casetracker_case_summary' => array(),
    'casetracker_project_summary' => array(),
  );
}

/**
 * Displays the changes a comment has made to the case fields.
 *
 * @param $case_data
 *   An array of both 'old' and 'new' objects that contains
 *   the before and after values this comment has changed.
 */
function theme_casetracker_comment_changes($old, $new) {
  $rows = array();

  $fields = array(
    'pid' => t('Project'),
    'title' => t('Title'),
    'case_status_id' => t('Status'),
    'assign_to' => t('Assigned'),
    'case_priority_id' => t('Priority'),
    'case_type_id' => t('Type'),
  );
  foreach ($fields as $field => $label) {
    if ($new->{$field} != $old->{$field}) {
      switch ($field) {
        case 'pid':
          $old_title = db_result(db_query("SELECT title FROM {node} WHERE nid = %d", $old->pid));
          $new_title = db_result(db_query("SELECT title FROM {node} WHERE nid = %d", $new->pid));
          $old->{$field} = l($old_title, "node/{$old->pid}");
          $new->{$field} = l($new_title, "node/{$new->pid}");
          break;
        case 'case_status_id':
          $old->{$field} = check_plain(casetracker_case_state_load($old->{$field}, 'status'));
          $new->{$field} = check_plain(casetracker_case_state_load($new->{$field}, 'status'));
          break;
        case 'assign_to':
          $old->{$field} = check_plain(casetracker_get_name($old->{$field}));
          $new->{$field} = check_plain(casetracker_get_name($new->{$field}));
          break;
        case 'case_priority_id':
          $old->{$field} = check_plain(casetracker_case_state_load($old->{$field}, 'priority'));
          $new->{$field} = check_plain(casetracker_case_state_load($new->{$field}, 'priority'));
          break;
        case 'case_type_id':
          $old->{$field} = check_plain(casetracker_case_state_load($old->{$field}, 'type'));
          $new->{$field} = check_plain(casetracker_case_state_load($new->{$field}, 'type'));
          break;
      }
      $rows[] = array(t('@label: !old &raquo; !new', array('@label' => $label, '!old' => $old->{$field}, '!new' => $new->{$field})));
    }
  }
  
  if (!empty($rows)) {
    return theme('table', NULL, $rows, array('class' => 'case_changes'));
  }
}

/**
 * Theme function for cleaning up the casetracker common form.
 */
function theme_casetracker_case_form_common($form) {
  drupal_add_css(drupal_get_path('module', 'casetracker') .'/casetracker.css');
  $output = '';
  $output .= drupal_render($form['pid']);
  $output .= drupal_render($form['case_title']);

  if ($form['assign_to']['#type'] == 'radios') {
    if ($form['assign_to']['#access']) {
      $header = array_fill(0, 5, array());
      $header[0] = $form['assign_to']['#title'];
      $radios = array();
      foreach (element_children($form['assign_to']) as $id) {
        $radios[] = drupal_render($form['assign_to'][$id]);
      }
      $radios = array_chunk($radios, 5);
      $output .= theme('table', $header, $radios, array('class' => 'casetracker-assign-to'));
    }
    drupal_render($form['assign_to']);
  }
  else {
    $output .= drupal_render($form['assign_to']);
  }

  $row = array();
  foreach (element_children($form) as $id) {
    if (!in_array($id, array('pid', 'case_title', 'assign_to'))) {
      $row[] = drupal_render($form[$id]);
    }
  }
  $rows = array($row);
  $output .= theme('table', array(), $rows);
  $output .= drupal_render($form);
  return $output;
}

/**
 * Theme the case summary shown at the beginning of a case's node.
 *
 * @param $case
 *   The node object of the case being viewed.
 * @param $project
 *   The node object of the project this case belongs to.
 */
function theme_casetracker_case_summary($case, $project) {
  $last_comment = db_result(db_query('SELECT last_comment_timestamp FROM {node_comment_statistics} WHERE nid = %d', $case->nid));
  $rows = array();

  // On node preview the form logic can't translate assign_to back to a uid for
  // us so we need to be able handle it either way.
  if (is_numeric($case->casetracker->assign_to)) {
    $assign_to = user_load(array('uid' => $case->casetracker->assign_to));
  }
  else {
    $assign_to = user_load(array('name' => $case->casetracker->assign_to));
  }

  if (empty($assign_to) || $assign_to->uid == 0) {
    $rows[] = array(
      t('Assigned to:'),
      '<em>' . t('Unassigned')  . '</em>',
    );
  }
  else {
    $rows[] = array(
      t('Assigned to:'),
      theme('username', $assign_to),
    );
  }
  $rows[] = array(
    t('Created:'),
    t('!username at !date', array('!username' => theme('username', $case), '!date' => format_date($case->created, 'medium'))),
  );
  $rows[] = array(
    t('Status:'),
    t('<strong>@status</strong> (@type / Priority @priority)', array(
      '@status' => casetracker_case_state_load($case->casetracker->case_status_id, 'status'),
      '@type' => casetracker_case_state_load($case->casetracker->case_type_id, 'type'),
      '@priority' => casetracker_case_state_load($case->casetracker->case_priority_id, 'priority'),
    )),
  );

  // On node preview a case may not have a nid, so we use some placeholder text.
  $case_id = isset($case->nid) ? $case->nid : t("NEW");
  $rows[] = array(
    t('Case ID:'),
    l($project->title, 'node/'. $case->casetracker->pid) .': '. $project->nid .'-'. $case_id,
  );
  if ($last_comment != $case->created) {
    $rows[] = array(
      t('Last modified:'),
      format_date($last_comment, 'medium')
    );
  }

  $output  = '<div class="case">';
  $output .= theme('table', NULL, $rows, array('class' => 'summary'));
  $output .= '</div>';
  return $output;
}

/**
 * Theme the project summary shown at the beginning of a project's node.
 *
 * @param $project
 *   The node object of the project being viewed.
 */
function theme_casetracker_project_summary($project) {
  $rows = array();
  $rows[] = array(t('Project number:'), $project->nid);
  $rows[] = array(t('Opened by:'), theme('username', $project));
  $rows[] = array(t('Opened on:'), format_date($project->created, 'large'));
  $rows[] = array(t('Last modified:'), format_date($project->changed, 'large'));

  $querystring = _casetracker_get_og_query_string($project);
  $operations = array(); $node_types = node_get_types('names');
  foreach (array_filter(variable_get('casetracker_case_node_types', array('casetracker_basic_case'))) as $type) {
    $operations[] = l(
      t('add !name', array('!name' => $node_types[$type])), 
      'node/add/'. str_replace('_', '-', $type) .'/'. $project->nid,
      array('query' => $querystring)
    );
  } 
  $operations = implode(' | ', $operations); // ready for printing in our Operations table cell - delimited by a pipe. nonstandard.
  $rows[] = array(t('Operations:'), $operations .' | '. l(t('view all project cases'), 'admin/casetracker', array('query' => 'keys=&pid='. $project->nid)));

  $output  = '<div class="project">';
  $output .= theme('table', NULL, $rows, array('class' => 'summary'));
  $output .= '</div>';
  return $output;
}

/**
 * API FUNCTIONS ======================================================
 */

/**
 * API function that returns valid project options.
 */
function casetracker_project_options() {
  $projects = array();
  // Fetch the views list of projects, which is space-aware.
  if ($view = views_get_view(variable_get('casetracker_view_project_options', 'casetracker_project_options'))) {
    $view->set_display();
    $view->set_items_per_page(0);
    $view->execute();
    foreach ($view->result as $row) {
      $projects[$row->nid] = $row->node_title;
    }
  }
  return $projects;
}

/**
 * API function that returns valid user options.
 */
function casetracker_user_options() {
  $users = array();
  $options = array();
  if ($view = views_get_view(variable_get('casetracker_view_assignee_options', 'casetracker_assignee_options'))) {
    $view->set_display();
    $view->set_items_per_page(0);
    $view->execute();
    foreach ($view->result as $row) {
      $options[$row->uid] = $row->users_name;
    }
  }

  $anon_user = casetracker_default_assign_to();

  // fill in "Unassigned" value because view is not rendered and the redundant option in views is irrelevant
  // @TODO render the view before display so this isn't needed.
  if (isset($options[0])) {
    $options[0] = $anon_user;
  }
  // if "Unassigned" is the default assignee, we graft it onto the view results here as most views
  // that do any substantive filtering will exclude the anonymous user.
  elseif (in_array(variable_get('casetracker_default_assign_to', $anon_user),  array($anon_user, variable_get('anonymous', t('Anonymous'))))) {
    $options = array($anon_user) + $options;
  }
  return $options;
}

/**
 * API function for checking whether a node type is a casetracker case.
 */
function casetracker_is_case($node) {
  if (is_object($node) && !empty($node->type)) {
    $type = $node->type;
  }
  else if (is_string($node)) {
    $type = $node;
  }
  if ($type) {
    return in_array($type, variable_get('casetracker_case_node_types', array('casetracker_basic_case')), TRUE);
  }
  return FALSE;
}

/**
 * API function for checking whether a node type is a casetracker project.
 */
function casetracker_is_project($node) {
  if (is_object($node) && !empty($node->type)) {
    $type = $node->type;
  }
  else if (is_string($node)) {
    $type = $node;
  }
  if ($type) {
    return in_array($type, variable_get('casetracker_project_node_types', array('casetracker_basic_project')), TRUE);
  }
  return FALSE;
}

/**
 * Given a user name, returns the uid of that account.
 * If the passed name is not found, returns 0.
 * See also casetracker_get_name().
 */
function casetracker_get_uid($name = NULL, $reset = FALSE) {
  static $users = array();
  if (!isset($users[$name]) || $reset) {
    $result = db_result(db_query("SELECT uid FROM {users} WHERE name = '%s'", $name));
    $users[$name] = $result ? $result : 0;
  }
  return $users[$name];
}

/**
 * Given a uid, returns the name of that account. If the passed uid is
 * not found, returns the default "assign to" name as specified in the
 * settings. @todo This may not always be desired, but is how we use it.
 * See also casetracker_get_uid().
 */
function casetracker_get_name($uid = NULL, $reset = FALSE) {
  static $users = array();
  if (!isset($users[$uid]) || $reset) {
    if ($uid == 0) {
      $users[0] = t('Unassigned'); 
    }
    else {
      $result = db_result(db_query("SELECT name FROM {users} WHERE uid = %d", $uid));
      $users[$uid] = $result ? $result : '';
    }
  }
  return !empty($users[$uid]) ? $users[$uid] : casetracker_default_assign_to();
}

/**
 * Fetch the proper default assignee.
 */
function casetracker_default_assign_to() {
  $assign_to = variable_get('casetracker_default_assign_to', t('Unassigned'));
  if ($assign_to == variable_get('anonymous', t('Anonymous'))) {
    return t('Unassigned');
  }
  return $assign_to;
}

/**
 * Implementation of hook_token_values().
 */
function casetracker_token_values($type, $object = NULL) {
  module_load_include('inc', 'casetracker', 'casetracker.token');
  return _casetracker_token_values($type, $object);
}

/**
 * Implementation of hook_token_list().
 */
function casetracker_token_list($type = 'all') {
  module_load_include('inc', 'casetracker', 'casetracker.token');
  return _casetracker_token_list($type);
}