<?php

/**
 * Implements hook_menu().
 */
function formflow_menu(){
  $items = array();
  $flows = formflow_get_flows();
  // Register the callbacks for each of these flows
  foreach($flows as $flow){
    // Keep a copy of the original path to use for the menu item
    $original_path = $flow['path'];
    // Append %step to flow path so the ctools wizard can handle next/back button clicks
    $flow['path'] .= '/%step';
    $items[$original_path] = formflow_menu_item($flow);
  }
  return $items;
}

/**
 * Implements hook_permission().
 */
function formflow_permission(){
  return array(
    'administer form flows' => array(
      'title' => t('Administer form flows')
    ),
    'create form flows' => array(
      'title' => t('Create new form flows')
    ),
    'edit form flows' => array(
      'title' => t('Edit form flows')
    ),
    'access form flows' => array(
      'title' => t('Access form flows'),
      'description' => t('Access form flows - users also need to have permissions for all of the forms in the flow (eg edit permissions for a node form).')
    )
  );
}

/**
 * Implements hook_form_alter().
 * Gets all the submit functions & moves them into $form_state['finish'] to be called upon completion
 * Hides all buttons - replacements will be added by ctools wizard
 */
function formflow_form_alter(&$form, &$form_state, $form_id){
  // Is this a formflow form?
  if(isset($form_state['formflow'])){
    // Array of submit functions to be called on completion
    $form_state['finish'] = array();
    foreach($form['#submit'] as $key => $submit){
      if($submit == 'ctools_wizard_submit' || $submit == 'formflow_submit'){
        continue;
      }
      unset($form['#submit'][$key]);
      $form_state['finish'][] = $submit;
    }
    // Node form uses actions for it's submit functions
    if(isset($form['actions'])){
      if(isset($form['actions']['submit']['#submit'])){
        $form_state['finish'] = array_merge($form_state['finish'], (array)$form['actions']['submit']['#submit']);
      }
      unset($form['actions']);
    }
    if(isset($form['submit'])){
      if(isset($form['submit']['#submit'])){
        $form_state['finish'] = array_merge($form_state['finish'], (array)$form['submit']['#submit']);
      }
      unset($form['submit']);
    }
    $form['#submit'][] = 'formflow_submit';
  }
}

/**
 * Implements hook_field_group_format_settings().
 *
 *
 *
 * @params Object $group The group object.
 * @return Array $form The form element for the format settings.
 */
function formflow_field_group_format_settings($group){
  // Add a wrapper for extra settings to use by others.
  $form = array(
    'instance_settings' => array(
      '#tree' => TRUE,
      '#weight' => 2
    )
  );
  $form['instance_settings']['display_mode'] = array(
    '#title' => t('Display mode'),
    '#type' => 'select',
    '#options' => array(
      '' => t('Add & edit'),
      'add' => t('Add only'),
      'edit' => t('Edit only')
    ),
    '#default_value' => isset($group->format_settings['instance_settings']['display_mode']) ? $group->format_settings['instance_settings']['display_mode'] : 'all',
    '#weight' => 3
  );
  return $form;
}

/**
 * Implements hook_field_attach_form().
 */
function formflow_field_attach_form($entity_type, $entity, &$form, &$form_state, $langcode){
  if(isset($entity->is_new)){
    // Some entities provide an "is_new" property. If that is present, respect
    // whatever it's set to.
    $is_new = $entity->is_new;
  }else{
    // Otherwise, try to find out if the entity is new by checking its ID. Note
    // that checking empty() rather than !isset() is important here, to deal
    // with the case of entities that store "0" as their ID while the final
    // entity is in the process of being created (user accounts are a good
    // example of this).
    list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
    $is_new = empty($id);
  }
  formflow_attach_groups($form, $form_state, ($is_new ? 'add' : 'edit'));
}

/**
 * Implements hook_field_group_formatter_info().
 */
function formflow_field_group_formatter_info(){
  return array(
    'form' => array(
      'formflow' => array(
        'label' => t('Formflow'),
        'description' => t('Treat this group as a stage in a formflow.'),
        'instance_settings' => array(
          'classes' => ''
        )
      )
    )
  );
}

/**
 * Implements hook_theme().
 */
function formflow_theme(){
  return array(
    // Theme the views plugin form table
    'formflow_wizard_trail' => array(
      'render element' => 'element',
      'file' => 'theme.inc'
    ),
    'formflow_group' => array(
      'render element' => 'element',
      'file' => 'theme.inc'
    )
  );
}

/**
 * Implements hook_features_api().
 */
function formflow_features_api(){
  return array(
    'formflow' => array(
      'name' => t('Form flows'),
      'default_hook' => 'default_flows',
      'feature_source' => TRUE,
      'duplicates' => FEATURES_DUPLICATES_ALLOWED,
      'file' => drupal_get_path('module', 'formflow') . '/formflow.features.inc'
    )
  );
}

/**
 * Get all flows
 */
function formflow_get_flows($name = null){
  // Load the flows from the DB
  $flows = formflow_load($name);
  // If we're just after one flow, see if we've got it at this point & return it
  if($name && !empty($flows) && isset($flows[$name])){return $flows[$name];}
  // Call hook_default_flows to get any modules defined in code
  foreach(module_implements('default_flows') as $module){
    foreach(module_invoke($module, 'default_flows') as $default_flow){
      // Don't overwrite DB flows - allows for overriding
      if(!isset($flows[$default_flow['name']])){
        $flows[$default_flow['name']] = $default_flow;
      }
      // Register that this is defined in code
      $flows[$default_flow['name']]['module'] = $module;
    }
  }
  if($name && !empty($flows)){return isset($flows[$name]) ? $flows[$name] : array();}
  return $flows;
}

/**
 * Implements hook_module_implements_alter().
 *
 * We need to ensure that this module's entity_info_alter fires after other
 * modules (particularly file_styles and media).
 */
function formflow_module_implements_alter(&$implementations, $hook){
  if($hook == 'field_attach_form'){
    $this_module = $implementations['formflow'];
    unset($implementations['formflow']);
    $implementations['formflow'] = $this_module;
  }
}

/*********************************************************************************************
 *
 * DB
 *
 ********************************************************************************************/
/**
 *
 * Retrieve all flows defined in DB
 * @param optional formflow name $name
 */
function formflow_load($name = null){
  $query = db_select('formflow', 'ff');
  $query->fields('ff');
  if($name){
    $query->condition('ff.name', $name);
  }
  $result = $query->execute();
  $flows = $result->fetchAllAssoc('name', PDO::FETCH_ASSOC);
  foreach($flows as $name => $flow){
    $flows[$name]['steps'] = formflow_load_steps($flow['fid']);
    // Unserliase the menu settings
    $flows[$name]['menu'] = unserialize($flows[$name]['menu']);
  }
  return $flows;
}

/**
 *
 * Retrieve the steps for a formflow from the db
 * @param formflow id $fid
 */
function formflow_load_steps($fid){
  $query = db_select('formflow_step', 'ffs');
  $query->fields('ffs', array(
    'title',
    'form_id',
    'path'
  ));
  $query->condition('fid', $fid, '=');
  $query->orderBy('weight', 'ASC');
  $result = $query->execute();
  $steps = $result->fetchAll(PDO::FETCH_ASSOC);
  return $steps;
}

function formflow_delete($fid){
  db_delete('formflow')->condition('fid', $fid, '=')->execute();
  formflow_delete_steps($fid);
}

function formflow_delete_steps($fid){
  db_delete('formflow_step')->condition('fid', $fid, '=')->execute();
}

/**
 *
 * Save a flow & it's steps
 * @param array / object $flow
 */
function formflow_save($flow){
  if(is_array($flow)){
    $flow = (object)$flow;
  }
  $update = array();
  if(isset($flow->fid)){
    $update[] = 'fid';
  }
  drupal_write_record('formflow', $flow, $update);
  // If steps are defined, save them to the database
  if(isset($flow->steps) && isset($flow->fid)){
    formflow_save_steps($flow->fid, $flow->steps);
  }
  formflow_menu_cache_clear();
}

/**
 * Save the form flow steps
 * @param flow id $fid
 * @param array of steps $steps
 */
function formflow_save_steps($fid, $steps){
  // Delete all steps
  formflow_delete_steps($fid);
  // Insert the new steps into the step table
  if(count($steps)){
    foreach($steps as $step){
      $record = (object)$step;
      $record->fid = $fid;
      drupal_write_record('formflow_step', $record);
    }
  }
}

/*********************************************************************************************
 *
 * MENU CALLBACKS & HELPERS
 *
 ********************************************************************************************/
function formflow_page($flow, $current_step = 0){
  global $user;
  $form_state = array();
  ctools_include('wizard');
  $flow['id'] = $flow['name'];
  $flow['finish callback'] = 'formflow_finish';
  $flow['return callback'] = 'formflow_finish';
  $flow['cancel callback'] = 'formflow_cancel';
  $flow['order'] = array();
  // Crappy database layer won't let you have spaces in field aliases! Rewrite the keys here
  foreach(array(
    'show_trail',
    'show_back',
    'show_cancel',
    'show_return',
    'cancel_path'
  ) as $old_key){
    if(isset($flow[$old_key])){
      $new_key = str_replace('_', ' ', $old_key);
      $flow[$new_key] = $flow[$old_key];
      unset($flow[$old_key]);
    }
  }
  foreach($flow['steps'] as $delta => $step){
    $flow['forms'][$delta] = array(
      'form id' => $flow['steps'][$delta]['form_id']
    );
    $flow['order'][$delta] = $flow['steps'][$delta]['title'];
  }
  $cache_id = $flow['name'];
  // If the form hasn't been submitted & step is 0, clear the cache
  if(!count($_POST) && $current_step === 0){
    formflow_cache_clear($cache_id);
  }
  if(!count($flow['steps'])){
    drupal_set_message(t('There are no forms in this flow.'), 'error');
    return '';
  }
  // check access for this url
  if(isset($flow['steps'][$current_step]['path'])){
    $item = menu_get_item($flow['steps'][$current_step]['path']);
    if($item['include_file']){
      $flow['steps'][$current_step]['include_file'] = $item['include_file'];
      require_once DRUPAL_ROOT . '/' . $item['include_file'];
    }
  }
  // This automatically gets defaults if there wasn't anything saved.
  $cache = formflow_cache_get($cache_id);
  $form_state = array(
    // Put our object and ID into the form state cache so we can easily find
    // it.
    'formflow' => array(
      'cache_id' => $cache_id,
      'cache' => &$cache
    )
  );
  // Is this a node type form
  if($strpos = strpos($flow['forms'][$current_step]['form id'], '_node_form')){
    $node_type = substr($flow['forms'][$current_step]['form id'], 0, $strpos);
    $node = (object)array(
      'uid' => $user->uid,
      'name' => (isset($user->name) ? $user->name : ''),
      'type' => $node_type,
      'language' => $user->language
    );
    $form_state['build_info']['args'] = array(
      $node
    );
  }elseif(isset($flow['steps'][$current_step]['path']) && !empty($flow['steps'][$current_step]['path']) && !drupal_valid_path($flow['steps'][$current_step]['path'])){
    drupal_access_denied();
  }
  // Allow other modules to make changes & additions before loading the form
  drupal_alter('formflow', $flow, $form_state);
  // Build the form
  $form = ctools_wizard_multistep_form($flow, $current_step, $form_state);
  if(!$form){
    if(!count($flow['forms'])){
      drupal_set_message(t('There are no forms in this flow.'), 'error');
    }else{
      drupal_set_message(t('Sorry, the form could not be found.'), 'error');
    }
    return '';
  }
  // Messy, but it works: after letting ctools wizard work it's magic, use our cached form if it exists
  if(isset($cache[$current_step]['form'])){
    $form = $cache[$current_step]['form'];
  }
  return $form;
}

/**
 * Create a menu item for a formflow
 *
 * @param $flow
 * The flow to use. Contains menu settings & path
 */
function formflow_menu_item($flow){
  $item = array(
    'access arguments' => array(
      'access form flows'
    ),
    'page callback' => 'formflow_page',
    'page arguments' => array(
      $flow
    )
  );
  if(isset($flow['menu']['title'])){
    $item['title'] = $flow['menu']['title'];
  }
  if(isset($flow['menu']['weight'])){
    $item['weight'] = $flow['menu']['weight'];
  }
  if(empty($flow['menu']['type'])){
    $flow['menu']['type'] = 'none';
  }
  switch($flow['menu']['type']){
    case 'none':
    default:
      $item['type'] = MENU_CALLBACK;
      break;
    case 'normal':
      $item['type'] = MENU_NORMAL_ITEM;
      // Insert item into the proper menu
      $item['menu_name'] = $flow['menu']['name'];
      break;
    case 'tab':
      $item['type'] = MENU_LOCAL_TASK;
      break;
    case 'action':
      $item['type'] = MENU_LOCAL_ACTION;
      break;
    case 'default tab':
      $item['type'] = MENU_DEFAULT_LOCAL_TASK;
      break;
  }
  return $item;
}

/**
 * Submit function for formflow
 */
function formflow_submit(&$form, &$form_state){
  $form_state['formflow']['cache'][$form_state['step']] = array(
    'form' => $form,
    'form_state' => $form_state
  );
  formflow_cache_set($form_state['formflow']['cache_id'], $form_state['formflow']['cache']);
}

/**
 * Handle the 'finish' click
 */
function formflow_finish(&$form_state){
  $form_state['complete'] = TRUE;
  // If a finish path has been set, redirect to it
  if(isset($form_state['form_info']['finish_path']) & !empty($form_state['form_info']['finish_path'])){
    $form_state['redirect'] = $form_state['form_info']['finish_path'];
  }else{
    $form_state['redirect'] = '<front>';
  }
  // Call all submit funtions for all forms in the step
  foreach($form_state['formflow']['cache'] as $delta => $cache){
    if(count($cache['form_state']['finish'])){
      foreach($cache['form_state']['finish'] as $func){
        if(isset($cache['form_state']['form_info']['steps'][$delta]['include_file'])){
          require_once DRUPAL_ROOT . '/' . $cache['form_state']['form_info']['steps'][$delta]['include_file'];
        }
        if(function_exists($func)){
          $func($cache['form'], $cache['form_state']);
        }
      }
    }
  }
  // Clear the caches
  formflow_cache_clear($form_state['formflow']['cache_id']);
}

/**
 * Handle the 'cancel' click
 */
function formflow_cancel(&$form_state){
  $form_state['cancel'] = TRUE;
}

/**
 * Specific cache_set and cache_get functions
 */
function formflow_cache_set($id, $cache){
  ctools_include('object-cache');
  ctools_object_cache_set('formflow', $id, $cache);
}

function formflow_cache_get($id){
  ctools_include('object-cache');
  return (array)ctools_object_cache_get('formflow', $id);
}

/**
 * Clear the wizard cache.
 */
function formflow_cache_clear($id){
  ctools_include('object-cache');
  ctools_object_cache_clear('formflow', $id);
}

/**
 * Clear the menu caches
 */
function formflow_menu_cache_clear(){
  menu_rebuild();
}

/**
 * Attach groups to the (form) build.
 * @param Array $element The part of the form.
 * @param String $view_mode The mode for the build.
 */
function formflow_attach_groups(&$form, &$form_state, $display_mode){
  // If there are no groups defined, do nothing
  if(!isset($form['#groups'])){return;}
  uasort($form['#groups'], 'formflow_sort_weight');
  // Build up a list of formfield groups.
  $formflow_groups = array();
  foreach($form['#groups'] as $group_name => $group){
    if($group->format_type == 'formflow'){
      $formflow_groups[] = $group_name;
    }
  }
  // If there are no formfield groups, do nothing.
  if(empty($formflow_groups)){return;}
  $form['#display_mode'] = $display_mode;
  ctools_add_css('wizard');
  // Attach the fieldgroup CSS
  $form['#attached']['css'] = array(
    drupal_get_path('module', 'formflow') . '/css/formflow.css'
  );
  // If there's no current step, default to the first one
  if(!isset($form_state['current_group'])){
    $form_state['current_group'] = @array_shift(array_keys($form['#groups']));
  }
  $form['#current_group'] = $form_state['current_group'];
  // Build a trail to display at the top of the form
  $form['trail'] = array(
    '#theme' => 'formflow_wizard_trail',
    '#value' => array(),
    '#weight' => -1000,
    '#formflow' => true
  );
  foreach($form['#groups'] as $group){
    if(empty($group->format_settings['instance_settings']['display_mode']) || $group->format_settings['instance_settings']['display_mode'] == $display_mode){
      if($group->group_name == $form['#current_group']){
        $class = 'wizard-trail-current';
      }else{
        $class = 'wizard-trail-next';
      }
      $form['trail']['#value'][] = '<span class="' . $class . '">' . $group->label . '</span>';
    }
  }
  // If there's still groups for this build mode, add some buttons
  if(count($form['trail']['#value'])){
    // Get the numeric position of the current group
    $form['#position'] = array_search($form['#current_group'], array_keys($form['#groups']));
    $form['formflow_actions'] = array(
      '#type' => 'actions'
    );
    // If this isn't the last group, show the back button
    if($form['#position'] > 0){
      $form['formflow_actions']['back'] = array(
        '#type' => 'submit',
        '#value' => t('Back'),
        '#weight' => -100,
        '#limit_validation_errors' => array(),
        '#submit' => array(
          'formflow_field_group_back_submit'
        ),
        '#formflow' => true // Set a flag to preserve this over all formflow steps
      );
    }
    // If this isn't the last group, show the next button
    if(($form['#position'] + 1) < count($form['#groups'])){
      $form['formflow_actions']['next'] = array(
        '#type' => 'submit',
        '#value' => t('Next'),
        '#limit_validation_errors' => array(),
        '#submit' => array(
          'formflow_field_group_next_submit'
        ),
        '#formflow' => true // Set a flag to preserve this over all formflow steps
      );
    }
    // limit validation errors to only the form items in the current group
    foreach($form['#group_children'] as $element_name => $group){
      if($group == $form['#current_group']){
        $form['formflow_actions']['next']['#limit_validation_errors'][] = array(
          $element_name
        );
      }
    }
  }
  return $form;
}

/**
 * Copy of drupal_sort_weight() for objects
 */
function formflow_sort_weight($a, $b){
  $a_weight = (is_object($a) && isset($a->weight)) ? $a->weight : 0;
  $b_weight = (is_object($b) && isset($b->weight)) ? $b->weight : 0;
  if($a_weight == $b_weight){return 0;}
  return ($a_weight < $b_weight) ? -1 : 1;
}

/**
 * Button submit function: handle the 'back' button on the form.
 */
function formflow_field_group_back_submit($form, &$form_state){
  $form_state['current_group'] = formflow_field_group_navigate('back', $form, $form_state);
  $form_state['rebuild'] = TRUE;
}

/**
 * Button submit function: handle the 'next' button on the form.
 */
function formflow_field_group_next_submit($form, &$form_state){
  $form_state['current_group'] = formflow_field_group_navigate('next', $form, $form_state);
  $form_state['rebuild'] = TRUE;
}

/**
 * Helper function for handling next/back navigation
 * @param string - direction of travel $op
 * @param array $form
 * @param array $form_state
 */
function formflow_field_group_navigate($op, $form, &$form_state){
  reset($form['#groups']);
  do{
    $current_group = current($form['#groups']);
    if($current_group->group_name == $form_state['current_group']){
      switch($op){
        case 'back':
          $prev_group = prev($form['#groups']);
          return $prev_group->group_name;
          break;
        case 'next':
          $next_group = next($form['#groups']);
          return $next_group->group_name;
          break;
      }
    }
  }
  while(next($form['#groups']));
}

/**
 * Implemntation of hook_field_group_pre_render
 * Adds the formflow field group elements
 * @see called by field_group_pre_render().
 * @param $element Array of group element that needs to be created!
 * @param $group Object with the group information.
 * @param $form The form object itself.
 */
function formflow_field_group_pre_render(&$element, $group, &$form){
  if(isset($form['#display_mode']) && (empty($group->format_settings['instance_settings']['display_mode']) || $group->format_settings['instance_settings']['display_mode'] == $form['#display_mode'])){
    $id = $form['#entity_type'] . '_' . $form['#bundle'] . '_' . $form['#display_mode'] . '_' . $group->group_name;
    // Prepare extra classes.
    $classes = array(
      'field-group-' . $group->format_type,
      str_replace('_', '-', $group->group_name)
    );
    if($group->group_name == $form['#current_group']){
      $classes[] = 'active-group';
    }
    switch($group->format_type){
      case 'formflow':
        $element += array(
          '#id' => $id,
          '#weight' => $group->weight,
          '#theme_wrappers' => array(
            'formflow_group'
          ),
          '#prefix' => '<div class="' . implode(' ', $classes) . '">',
          '#suffix' => '</div>',
          '#group' => $group->format_type
        );
        break;
    }
    // Loop through & identify which group is the last one with required fields
    // We can then use this to decide when to show the submit buttons
    foreach(element_children($element) as $key){
      if(is_array($instance = field_info_instance($form['#entity_type'], $key, $form['#bundle']))){
        if($instance['required']){
          $form['#last_required_group'] = $group->group_name;
          break;
        }
      }
    }
  }
}

/**
 * Implements hook_field_group_build_pre_render_alter
 * Make changes so only relevant bits of the form are shown
 * @param form $element
 */
function formflow_field_group_build_pre_render_alter(&$form){
  // Are there trails in the form?
  if(isset($form['#display_mode']) && count($form['trail']['#value'])){
    // Variable denoting this stage is a form endpoint
    $end_point = false;
    if(isset($form['actions']) && isset($form['formflow_actions'])){
      $form['actions'] += $form['formflow_actions'];
      unset($form['formflow_actions']);
    }
    // If there are actions & formflow_actions, merge them together
    // If we are on the last step on the form, do nothing
    // We'll want to show all buttons
    if(($form['#position'] + 1) == count($form['#groups'])){return;}
    if(!isset($form['changed']) || empty($form['changed']['#value'])){
      if(isset($form['#last_required_group'])){
        // Loop through the groups - if we're not past the last required group in the flow, hide the buttons
        foreach($form['#groups'] as $group_name => $group){
          // If the current group is before the last required group, update the buttons
          if($group_name == $form['#last_required_group']){
            // Can the user end at this stage of the form?
            $end_point = true;
            break;
          }
          if($group_name == $form['#current_group']){
            break;
          }
        }
      }else{
        $end_point = true;
      }
    }
    formflow_field_group_remove_elements($form, $end_point);
  }
}

/**
 * Remove the default submit buttons
 * @param form element $element
 */
function formflow_field_group_remove_elements(&$form, $end_point){
  foreach(element_children($form) as $key){
    if(isset($form[$key]['#formflow']) || (isset($form[$key]['#type']) && in_array($form[$key]['#type'], array(
      'value',
      'hidden',
      'token'
    ))) || ($end_point && isset($form[$key]['#type']) && $form[$key]['#type'] == 'submit')){
      continue;
    }
    if(isset($form[$key]['#type']) && ($form[$key]['#type'] == 'actions' || $form[$key]['#type'] == 'container') && count(element_children($form[$key]))){
      formflow_field_group_remove_elements($form[$key], $end_point);
    }elseif(!(isset($form[$key]['#group']) && $form[$key]['#group'] == 'formflow')){
      unset($form[$key]);
    }
  }
  return $form;
}