<?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_farm_admin_actions().
 */
function farm_log_farm_admin_actions() {

  // Define farm area actions.
  $actions = array(
    'activity' => array(
      'title' => t('Add an activity'),
      'href' => 'log/add/farm_activity',
      'assets' => array(
        'all',
      ),
      'views' => array(
        'farm_log_activity',
      ),
      'paths' => array(
        'farm',
        'farm/plan',
        'taxonomy/term/%',
      ),
    ),
    'movement' => array(
      'title' => t('Add a movement'),
      'href' => 'log/add/farm_movement',
      'assets' => array(
        'all',
      ),
      'views' => array(
        'farm_log_movement',
      ),
      'paths' => array(
        'farm',
        'farm/plan',
        'taxonomy/term/%',
      ),
    ),
    'observation' => array(
      'title' => t('Add an observation'),
      'href' => 'log/add/farm_observation',
      'assets' => array(
        'all',
      ),
      'views' => array(
        'farm_log_observation',
      ),
      'paths' => array(
        'farm',
        'farm/plan',
        'taxonomy/term/%',
      ),
    ),
  );
  return $actions;
}

/**
 * Implements hook_farm_taxonomy_term_view_views().
 */
function farm_log_farm_taxonomy_term_view_views($term) {

  // If the term is not an area, bail.
  if ($term->vocabulary_machine_name != 'farm_areas') {
    return array();
  }

  // Return a list of Views to include on Areas.
  return array(

    // Activities in this area.
    array(
      'name' => 'farm_log_activity',
      'arg' => 2,
    ),

    // Observations in this area.
    array(
      'name' => 'farm_log_observation',
      'arg' => 2,
    ),

    // Area asset history (at the bottom).
    array(
      'name' => 'farm_area_assets',
      'weight' => 100,
    ),
  );
}

/**
 * Implements hook_farm_area_links().
 */
function farm_log_farm_area_links($id) {
  return array(
    array(
      'title' => t('Activities'),
      'href' => 'taxonomy/term/' . $id,
      'options' => array(
        'fragment' => 'Activities',
      ),
      'weight' => -100,
    ),
    array(
      'title' => t('Observations'),
      'href' => 'taxonomy/term/' . $id,
      'options' => array(
        'fragment' => 'Observations',
      ),
      'weight' => -90,
    ),
  );
}

/**
 * Implements hook_entity_view_alter().
 */
function farm_log_entity_view_alter(&$build, $type) {

  /*
   * Alter farm assets to display their current location.
   */

  // If it's not a farm_asset, bail.
  if ($type != 'farm_asset') {
    return;
  }

  // If the entity information isn't available, bail.
  if (empty($build['#entity'])) {
    return;
  }
  $asset = $build['#entity'];

  // Start an output string.
  $output = '<strong>Current location:</strong> ';

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

  // If a location was found, add a link to it.
  if (!empty($area->tid)) {
    $output .= l($area->name, 'taxonomy/term/' . $area->tid);
  }

  // Otherwise, none.
  else {
    $options = array(
      'query' => array(
        'destination' => 'farm/asset/' . $asset->id,
        'farm_asset' => $asset->id,
      ),
    );
    $link = l(t('add a movement'), 'log/add/farm_movement', $options);
    $output .= 'N/A (' . $link . ')';
  }

  // Add it to the build array.
  $build['location'] = array(
    '#markup' => $output,
    '#weight' => -100,
  );
}

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

  // If this is a log form...
  if ($form_id == 'log_form') {

    // If there is an asset(s) reference field.
    if (!empty($form['field_farm_asset'])) {

      // Alter the form using our helper function.
      // ($asset is used below for movement logs.)
      $asset = farm_log_form_prepopulate_asset($form, 'field_farm_asset', TRUE);
    }

    // If there is an area(s) reference field...
    if (!empty($form['field_farm_area'])) {

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

    // If this is a farm_movement...
    if ($form['#bundle'] == 'farm_movement') {

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

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

      // If no asset was found above, 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;
        }
      }
    }

    // Or, if this is a farm_observation...
    elseif ($form['#bundle'] == 'farm_observation') {

      // If the observation type field is empty, prepopulate it with "General".
      if (empty($form['field_farm_observation_type'][LANGUAGE_NONE]['#default_value'])) {
        $form['field_farm_observation_type'][LANGUAGE_NONE]['#default_value'] = t('General');
      }
    }
  }

  // Or, if this is a farm_asset form.
  elseif ($form_id == 'farm_asset_form') {

    // Get the farm asset entity from the form.
    $asset = $form['farm_asset']['#value'];

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

    // Add a field for setting the asset's current location.
    $form['farm_log_asset_location'] = array(
      '#type' => 'textfield',
      '#title' => t('Current location'),
      '#description' => t('Set the current location of this asset. Asset location is determined by movement logs, so a movement log will automatically be generated if you change this field.'),
      '#autocomplete_path' => 'taxonomy/autocomplete/field_farm_area',
      '#default_value' => !empty($location->name) ? $location->name : '',
    );
    $form['actions']['submit']['#submit'][] = 'farm_log_asset_location_submit';
  }
}

/**
 * Submit handler for processing the asset location field.
 *
 * @param array $form
 *   The form array.
 * @param array $form_state
 *   The form state array.
 */
function farm_log_asset_location_submit(array $form, array &$form_state) {

  // Only proceed if farm_log_asset_location has a value.
  if (empty($form_state['values']['farm_log_asset_location'])) {
    return;
  }

  // Only proceed if the value is not the default value.
  if ($form_state['values']['farm_log_asset_location'] == $form['farm_log_asset_location']['#default_value']) {
    return;
  }

  // If an asset doesn't exist, bail.
  if (empty($form_state['values']['farm_asset'])) {
    return;
  }

  // Grab the asset.
  $asset = $form_state['values']['farm_asset'];

  // Explode the value into an array and only take the first value.
  // (Same behavior as taxonomy autocomplete widget.)
  $values = explode(',', $form_state['values']['farm_log_asset_location']);
  $value = trim(reset($values));

  // If the value is empty, bail.
  if (empty($value)) {
    return;
  }

  // Attempt to look up the area by it's name.
  $areas = taxonomy_get_term_by_name($value, 'farm_areas');
  $area = reset($areas);

  // If an area was not found, create a new one.
  if (empty($area)) {
    $farm_areas = taxonomy_vocabulary_machine_name_load('farm_areas');
    $area = new stdClass();
    $area->name = $value;
    $area->vid = $farm_areas->vid;
    taxonomy_term_save($area);
  }

  // Create a movement log.
  farm_log_move_assets($asset, $area->tid, REQUEST_TIME, TRUE);
}

/**
 * Find the location of an asset.
 *
 * @param FarmAsset $asset
 *   The farm_asset object to look for.
 * @param int $time
 *   Unix timestamp limiter. Only movement logs before this time will be
 *   included. Defaults to the current time. Set to 0 to load the absolute last.
 * @param bool $done
 *   Whether or not to only show movement logs that are marked as "done".
 *   Defaults to TRUE.
 *
 * @return area
 *   Returns the area that the asset is in.
 */
function farm_log_asset_location(FarmAsset $asset, $time = REQUEST_TIME, $done = TRUE) {
  $area = NULL;
  $query = new EntityFieldQuery();
  $query->entityCondition('entity_type', 'log')
    ->entityCondition('bundle', 'farm_movement')
    ->fieldCondition('field_farm_asset', 'target_id', $asset->id)
    ->propertyOrderBy('timestamp', 'DESC')
    ->propertyOrderBy('id', 'DESC')
    ->range(0, 1);
  if (!empty($time)) {
    $query->propertyCondition('timestamp', $time, '<=');
  }
  if (!empty($done)) {
    $query->propertyCondition('done', TRUE);
  }
  $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)) {
          $area = $term;
          break;
        }
      }
    }
  }
  return $area;
}

/**
 * Build a query to find the latest movement log of an asset.
 *
 * @param int|string $asset_id
 *   The asset id to search for. This can either be a specific id, or a field
 *   alias string from another query (ie: 'mytable.assetid'). For an example
 *   of field alias string usage, see the Views field handler code in
 *   farm_log_handler_relationship_location::query().
 * @param bool $done
 *   Whether or not to include only logs that are done. Defaults to TRUE.
 * @param bool $future
 *   Whether or not to include logs with a timestamp in the future. Defaults to
 *   FALSE.
 *
 * @return \SelectQuery
 *   Returns a SelectQuery for finding the latest log.
 */
function farm_log_asset_movement_query($asset_id, $done = TRUE, $future = FALSE) {

  // Build a sub-query that will be used in the join to load the latest
  // movement log of a given asset.
  $query = db_select('log', 'ss_log');
  $query->join('field_data_field_farm_asset', 'ss_fdffa', 'ss_log.id = ss_fdffa.entity_id');
  $query->where("ss_log.type = 'farm_movement'");
  $query->where('ss_fdffa.field_farm_asset_target_id = ' . $asset_id);
  $query->where('ss_fdffa.deleted = 0');
  $query->orderBy('ss_log.timestamp', 'DESC');
  $query->orderBy('ss_log.id', 'DESC');
  $query->range(0, 1);
  $query->addField('ss_log', 'id');

  // If only "done" movement logs should be included, add a filter.
  if ($done) {
    $query->where('ss_log.done = 1');
  }

  // If future logs should not be included, then limit to only logs that
  // have a date before right now.
  if (!$future) {
    $query->where('ss_log.timestamp <= ' . REQUEST_TIME);
  }

  // Return the query object.
  return $query;
}

/**
 * Helper function for enabling asset prepopulation in log forms.
 *
 * @param array $form
 *   The form array to modify, passed by reference.
 * @param string $field_name
 *   The machine name of the entity reference field that should be populated.
 * @param bool $tags
 *   Whether or not the field is using the "Tags style" entity reference
 *   widget. Defaults to FALSE.
 *
 * @return FarmAsset farm_asset
 *   Returns the asset object, if found.
 */
function farm_log_form_prepopulate_asset(array &$form, $field_name = 'field_farm_asset', $tags = FALSE) {
  $asset = NULL;

  // The location of the field's default value depends on whether or not it is
  // a "Tags style" entity reference field.
  if (empty($tags)) {
    $field_value = &$form[$field_name][LANGUAGE_NONE][0]['target_id']['#default_value'];
  }
  else {
    $field_value = &$form[$field_name][LANGUAGE_NONE]['#default_value'];
  }

  // 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($field_value)) {
        $field_value = entity_label('farm_asset', $asset) . ' (' . $asset->id . ')';
      }
    }
  }

  return $asset;
}

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

  // Alias for the field's default value.
  $field_value = &$form[$field_name][LANGUAGE_NONE]['#default_value'];

  // 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($field_value)) {
        $field_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'),
      'aggregate' => TRUE,
    ),
  );
}

/**
 * Asset move action configuration form.
 *
 * @param array $context
 *   The action context array.
 * @param array $form_state
 *   The form state array.
 *
 * @return array
 *   Returns a form array.
 */
function farm_log_asset_move_action_form(array $context, array $form_state) {

  // Add Javascript to improve UX.
  drupal_add_js(drupal_get_path('module', 'farm_log') . '/js/move_action.js');

  // Build a list of the assets being moved.
  if (!empty($form_state['selection'])) {
    $assets = array();
    $query = db_select('farm_asset', 'a');
    $query->addField('a', 'name');
    $query->condition('a.id', $form_state['selection']);
    $results = $query->execute();
    foreach ($results as $result) {
      $assets[] = $result->name;
    }

    // If there is more than one asset, theme an item list.
    if (count($assets) > 1) {
      $markup = theme('item_list', array('items' => $assets, 'title' => t('Move Assets:')));
    }

    // Otherwise, display the one.
    else {
      $markup = '<h3>' . t('Move') . ' ' . reset($assets) . '</h3>';
    }

    // Display the asset(s) in the form.
    $form['assets'] = array(
      '#type' => 'markup',
      '#markup' => $markup,
    );
  }

  // "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,
  );

  // Convert the timestamp to the format Date API expects.
  $default_value = date('Y-m-d H:i', REQUEST_TIME);

  // "Date" field: default to current date.
  $form['timestamp'] = array(
    '#type' => 'date_select',
    '#title' => t('Date'),
    '#date_format' => 'M j Y',
    '#date_type' => DATE_FORMAT_UNIX,
    '#date_year_range' => '-10:+3',
    '#default_value' => $default_value,
    '#required' => TRUE,
  );

  // "Done" field: mark movements as done.
  $form['done'] = array(
    '#type' => 'checkbox',
    '#title' => t('Movement is done'),
    '#description' => t('Check this if the movement has already been done. Otherwise, you will need to mark the movement log item as done later.'),
    '#default_value' => TRUE,
  );

  return $form;
}

/**
 * Asset move action configuration form submit.
 *
 * @param array $form
 *   The form array.
 * @param array $form_state
 *   The form state array.
 *
 * @return array
 *   Returns an array of variables to pass to the action function.
 */
function farm_log_asset_move_action_submit(array $form, array $form_state) {
  return array(
    'to' => $form_state['values']['to'],
    'timestamp' => $form_state['values']['timestamp'],
    'done' => $form_state['values']['done'],
  );
}

/**
 * Action function for farm_log_asset_move_action.
 *
 * Creates a new movement record for the specified assets.
 *
 * @param array $assets
 *   An array of asset entities to move.
 * @param array $context
 *   Array with parameters for this action.
 */
function farm_log_asset_move_action(array $assets, $context = array()) {

  // Assemble parameters.
  $area_id = $context['to'];
  $timestamp = (!empty($context['timestamp'])) ? strtotime($context['timestamp']) : REQUEST_TIME;
  $done = (!empty($context['done'])) ? TRUE : FALSE;

  // Delegate to the helper function.
  farm_log_move_assets($assets, $area_id, $timestamp, $done);
}

/**
 * Move farm asset(s) to an area. Creates a movement log.
 *
 * @param array|FarmAsset $assets
 *   Array of assets to include in the move.
 * @param int $area_id
 *   The id of the area to move to.
 * @param int $timestamp
 *   The timestamp of the move.
 * @param bool $done
 *   Whether or not to mark the movement done. Default to FALSE.
 */
function farm_log_move_assets($assets, $area_id, $timestamp, $done = FALSE) {

  // If $assets isn't an array, wrap it.
  if (!is_array($assets)) {
    $assets = array($assets);
  }

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

  // Keep track of what areas these assets are coming from.
  $from_areas = array();

  // Iterate through the assets.
  foreach ($assets as $asset) {

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

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

    // If the asset has a current location, add it to the "from" field.
    // Avoid adding the same area more than once.
    if (!empty($area->name) && !empty($area->tid) && !in_array($area->tid, $from_areas)) {
      $log->field_farm_move_from[LANGUAGE_NONE][] = array(
        'tid' => $area->tid,
      );
      $from_areas[] = $area->tid;
    }
  }

  // Set the date.
  $log->timestamp = $timestamp;

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

  // Set the log's done status.
  $log->done = $done;

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