<?php
/**
 * @file
 * Code for the Farm Log feature.
 */

include_once 'farm_log.features.inc';

/**
 * Implements hook_permission().
 */
function farm_log_permission() {
  return array(
    'view farm logs' => array(
      'title' => t('View farm logs'),
      'description' => t('View all farm-related log items.'),
    ),
  );
}

/**
 * Implements hook_menu_local_tasks_alter().
 */
function farm_log_menu_local_tasks_alter(&$data, $router_item, $root_path) {

  // Define actions.
  $actions = array(
    'activity' => array(
      'title' => t('Add an activity'),
      'href' => 'log/add/farm_activity',
    ),
    'movement' => array(
      'title' => t('Add a movement'),
      'href' => 'log/add/farm_movement',
    ),
    'issue' => array(
      'title' => t('Add an issue'),
      'href' => 'log/add/farm_issue',
    ),
    'observation' => array(
      'title' => t('Add an observation'),
      'href' => 'log/add/farm_observation',
    ),
  );

  // Define actions for various paths.
  $path_actions = array(
    'farm/area/%/activities' => array('activity'),
    'farm/asset/%' => array('movement', 'observation'),
    'farm/asset/%/movements' => array('movement'),
    'farm/asset/%/observations' => array('observation'),
    'admin/farm' => array('activity', 'issue', 'observation'),
    'admin/farm/plan/activities' => array('activity'),
    'admin/farm/plan/movements' => array('movement'),
    'admin/farm/plan/issues' => array('issue'),
    'admin/farm/plan/observations' => array('observation'),
    'taxonomy/term/%' => array('activity'),
  );

  // Add actions depending on the root path.
  if (array_key_exists($root_path, $path_actions)) {
    foreach ($path_actions[$root_path] as $action) {
      $output = array(
        '#theme' => 'menu_local_action',
        '#link' => array(
          'title' => $actions[$action]['title'],
          'href' => $actions[$action]['href'],
          'localized_options' => array(
            'query' => array(
              'destination' => $root_path,
            ),
          ),
        ),
      );

      // If this is a farm asset movements path...
      if (in_array($root_path, array(
          'farm/asset/%',
          'farm/asset/%/movements'
        ))) {

        // Get the asset id from the path.
        $asset_id = check_plain(arg(2));

        // Set the destination to the farm asset page.
        $output['#link']['localized_options']['query']['destination'] = 'farm/asset/' . $asset_id;

        // Set the farm_asset query string to the asset id. This will be used to
        // prepopulate asset reference fields in log entities.
        // See hook_form_alter() below
        $output['#link']['localized_options']['query']['farm_asset'] = $asset_id;
      }

      // Or, if this is an area path...
      elseif ($root_path == 'taxonomy/term/%' || substr($root_path, 0, 11) == 'farm/area/%') {

        // Get the asset id from the path.
        $area_id = check_plain(arg(2));

        // Load the area.
        $farm_area = taxonomy_term_load($area_id);

        // If the taxonomy term is not a farm_area, bail.
        if (empty($farm_area->vocabulary_machine_name) || $farm_area->vocabulary_machine_name != 'farm_areas') {
          continue;
        }

        // Set the destination to the farm area page.
        $output['#link']['localized_options']['query']['destination'] = 'taxonomy/term/' . $area_id;

        // Set the farm_area query string to the area id. This will be used to
        // prepopulate area reference fields in log entities.
        // See hook_form_alter() below
        $output['#link']['localized_options']['query']['farm_area'] = $area_id;
      }

      // Add the action output.
      if (!empty($output)) {
        $data['actions']['output'][] = $output;
      }
    }
  }
}

/**
 * Implements hook_farm_area_links().
 */
function farm_log_farm_area_links($id) {
  return array(
    array(
      'title' => t('Activities'),
      'href' => 'farm/area/' . $id . '/activities',
      'weight' => -100,
    ),
  );
}


/**
 * Implements hook_form_alter().
 */
function farm_log_form_alter(&$form, &$form_state, $form_id) {

  // If this is the farm_movement log form...
  if ($form_id == 'log_form' && $form['#bundle'] == 'farm_movement') {

    // Alter the form using our helper function.
    $asset = farm_log_form_prepopulate_asset($form, 'field_farm_asset');

    // If no asset was returned, don't continue.
    if (empty($asset)) {
      return;
    }

    // If the "from" field is empty...
    if (empty($form['field_farm_move_from'][LANGUAGE_NONE][0]['#default_value'])) {

      // Look up the asset's last location and prepopulate the "from" field.
      $area = farm_log_asset_location($asset);
      if (!empty($area->name)) {
        $form['field_farm_move_from'][LANGUAGE_NONE]['#default_value'] = $area->name;
      }
    }
  }

  // If this is a log form with an area(s) reference field...
  if ($form_id == 'log_form' && (!empty($form['field_farm_area']) || !empty($form['field_farm_areas']))) {

    // First choice is farm_area, second is farm_areas.
    $field_name = (!empty($form['field_farm_area'])) ? 'field_farm_area' : 'field_farm_areas';

    // Alter the form with the farm_log helper function.
    farm_log_form_prepopulate_area($form, $field_name);
  }
}

/**
 * Find the location of an asset.
 *
 * @param FarmAsset $asset
 *   The farm_asset object to look for.
 *
 * @return area
 *   Returns the area that the asset is in.
 */
function farm_log_asset_location(FarmAsset $asset) {
  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'log')
    ->entityCondition('bundle', 'farm_movement')
    ->fieldCondition('field_farm_asset', 'target_id', $asset->id)
    ->fieldCondition('field_farm_date', 'value', REQUEST_TIME, '<=')
    ->fieldOrderBy('field_farm_date', 'value', 'DESC')
    ->propertyOrderBy('id', 'DESC')
    ->range(0, 1);
  $result = $query->execute();
  if (!empty($result['log'])) {
    foreach ($result['log'] as $id => $entity) {
      $log = log_load($id);
      if (!empty($log->field_farm_move_to[LANGUAGE_NONE][0]['tid'])) {
        $term = taxonomy_term_load($log->field_farm_move_to[LANGUAGE_NONE][0]['tid']);
        if (!empty($term)) {
          return $term;
        }
      }
    }
  }
}

/**
 * Helper function for enabling asset prepopulation in log forms.
 *
 * @param $form
 *   The form array to modify, passed by reference.
 * @param $field_name
 *   The machine name of the entity reference field that should be populated.
 *
 * @return FarmAsset farm_asset
 *   Returns the asset object, if found.
 */
function farm_log_form_prepopulate_asset(&$form, $field_name = 'field_farm_asset') {
  $asset = NULL;

  // If the "farm_asset" query parameter is set...
  $params = drupal_get_query_parameters();
  if (!empty($params['farm_asset'])) {

    // Verify that the farm_asset is valid.
    $asset = farm_asset_load($params['farm_asset']);
    if ($asset) {

      // Add the asset to the form.
      $form['farm_asset'] = array(
        '#type' => 'value',
        '#value' => $asset,
      );

      // Prepopulate the asset reference field.
      if (empty($form[$field_name][LANGUAGE_NONE][0]['target_id']['#default_value'])) {
        $form[$field_name][LANGUAGE_NONE][0]['target_id']['#default_value'] = entity_label('farm_asset', $asset) . ' (' . $asset->id . ')';
      }
    }
  }

  // If the asset field is not empty, hide it so that it can't be changed.
  if (!empty($form[$field_name][LANGUAGE_NONE][0]['target_id']['#default_value'])) {
    $form[$field_name]['#access'] = FALSE;
  }

  return $asset;
}

/**
 * Helper function for enabling area prepopulation in log forms.
 *
 * @param $form
 *   The form array to modify, passed by reference.
 * @param $field_name
 *   The machine name of the term reference field that should be populated.
 *
 * @return TaxonomyTerm term
 *   Returns the taxonomy term object, if found.
 */
function farm_log_form_prepopulate_area(&$form, $field_name = 'field_farm_area') {
  $area = NULL;

  // If the "farm_area" query parameter is set...
  $params = drupal_get_query_parameters();
  if (!empty($params['farm_area'])) {

    // Verify that the farm_area is valid.
    $area = taxonomy_term_load($params['farm_area']);
    if ($area) {

      // Add the area to the form.
      $form['farm_area'] = array(
        '#type' => 'value',
        '#value' => $area,
      );

      // Prepopulate the area reference field.
      if (empty($form[$field_name][LANGUAGE_NONE]['#default_value'])) {
        $form[$field_name][LANGUAGE_NONE]['#default_value'] = entity_label('taxonomy_term', $area);
      }
    }
  }

  return $area;
}

/**
 * Implements hook_action_info().
 */
function farm_log_action_info() {
  return array(
    'farm_log_asset_move_action' => array(
      'type' => 'farm_asset',
      'label' => t('Move'),
      'configurable' => TRUE,
      'triggers' => array('any'),
    )
  );
}

/**
 * Asset move action configuration form.
 */
function farm_log_asset_move_action_form($context, $form_state) {

  // "To" field: select list of areas.
  $form['to'] = array(
    '#type' => 'select',
    '#title' => t('To'),
    '#options' => taxonomy_allowed_values(field_info_field('field_farm_move_to')),
    '#required' => TRUE,
  );

  return $form;
}

/**
 * Asset move action configuration form submit.
 */
function farm_log_asset_move_action_submit($form, $form_state) {
  return array(
    'to' => $form_state['values']['to'],
  );
}

/**
 * Action function for farm_log_asset_move_action.
 *
 * Creates a new movement record for the specified asset.
 *
 * @param object $entity
 *   An optional entity object.
 * @param array $context
 *   Array with parameters for this action.
 */
function farm_log_asset_move_action($entity, $context = array()) {

  // Pull the asset out of the context.
  $asset = $context['farm_asset'];

  // Create a new movement log entity.
  $log = entity_create('log', array('type' => 'farm_movement'));

  // Set the asset.
  $log->field_farm_asset[LANGUAGE_NONE][] = array(
    'target_id' => $asset->id,
  );

  // Set the date.
  $log->field_farm_date[LANGUAGE_NONE][] = array(
    'value' => REQUEST_TIME,
  );

  // Load the asset's current location.
  $area = farm_log_asset_location($asset);

  // If the asset has a current location, set the "from" area.
  if (!empty($area->name) && !empty($area->tid)) {
    $log->field_farm_move_from[LANGUAGE_NONE][] = array(
      'tid' => $area->tid,
    );
  }

  // Set the "to" area.
  $log->field_farm_move_to[LANGUAGE_NONE][] = array(
    'tid' => $context['to'],
  );

  // Save the movement.
  log_save($log);
}