<?php
// $Id: viewfield.module,v 1.3 2007-02-05 03:23:48 mfredrickson Exp $

/**
 * @file
 * Defines a field type for referencing a view from a node
 */


/**
 * Implementation of hook_field_info().
 */
function viewfield_field_info() {
  return array(
    'viewfield' => array('label' => 'View Reference'),
  );
}

/**
 * Implementation of hook_field_settings().
 */
function viewfield_field_settings($op, $field) {
  switch ($op) {
  /* These are off until we need them
    case 'form':
      return $form;

    case 'save':
      return array(); */

    case 'database columns':
      $columns = array(
        'vname' => array('type' => 'char', 'length' => 32),
        'vargs' => array('type' => 'varchar', 'not null' => false, 'default' => "''", 'sortable' => TRUE, 'length' => 255),
      );

      return $columns;

    /*
    case 'filters':
      return array(
        'default' => array(
        'list' => '_viewfield_filter_handler',
        'list-type' => 'list',
        'operator' => 'views_handler_operator_or',
        'value-type' => 'array',
        'extra' => array('field' => $field),
      ),
    ); */
  }
}

/**
 * Implementation of hook_field_formatter_info().
 */
function viewfield_field_formatter_info() {
  return array(
    'default' => array(
      'label' => 'Entire view',
      'field types' => array('viewfield'),
    ),
    'count' => array(
      'label' => 'Count of items in view',
      'field types' => array('viewfield'),
    ),
  );
}

/**
 * Implementation of hook_field_formatter().
 */
function viewfield_field_formatter($field, $item, $formatter, $node) {

  if (!empty($item['vname'])) {
    // XXX this probably not multi-select safe...
    global $user;
    $view = views_get_view($item['vname']);
    $translated_args = strtr($item['vargs'], array('%nid' => $node->nid, '%author' => $node->nid, '%viewer' => $user->uid));
    $args = explode(',', $translated_args);
    
    // need to prevent recusive views and node building, but don't need to do it on new node previews
    if ($node->nid) {
      _viewfield_nodestack_push($node->nid);
    }

    switch ($formatter) {
      default:
        if ($view->use_pager) {
        	// fix for multiple pagers
          global $pager_total;
          static $viewfield_pager_elements = array();
          $key = $node->nid . '-' . $field['field_name'] . '-' . $view->name;  // set a unique key for the view in the current node
          if (!isset($viewfield_pager_elements[$key])) {
            // set the viewfield pager element to the max + 1
            $max1 = is_array($pager_total) ? @max(array_values($pager_total)) : 1;
            $max2 = @max(array_values($viewfield_pager_elements));
            $viewfield_pager_elements[$key] = @max($max1, $max2) + 1;
          }
          $use_pager = $viewfield_pager_elements[$key];
        }
        else {
          $use_pager = 0;
        }
        $output = views_build_view('embed', $view, $args, $use_pager, $view->nodes_per_page);
        break;
        
      case 'count':
        // TODO use the the new 'queries' $op instead
        $results = views_build_view('items', $view, $args);
        $count = count($results['items']);
        $output = $count;
        break;
    }
    
    // this node is "safe" again
    if ($node->nid) {
      _viewfield_nodestack_pop();
    }
    
    return $output;
  }
}

/**
 * Implementation of hook_widget_info().
 */
function viewfield_widget_info() {
  return array(
    'viewfield_select' => array(
      'label' => 'Select List',
      'field types' => array('viewfield'),
    ), /*
    'viewfield_autocomplete' => array(
      'label' => 'Autocomplete View Field',
      'field types' => array('viewfield'),
    ), */
  );
}

/**
 * Implementation of hook_widget().
 */
function viewfield_widget($op, &$node, $field, &$node_field) {

  switch ($op) {
    case 'prepare form values':
      $node_field_transposed = content_transpose_array_rows_cols($node_field);
      $node_field['default vnames'] = $node_field_transposed['vname'];
      break;

    case 'form':
      $form = array();

      $options = _viewfield_potential_references($field);
      
      $form[$field['field_name']] = array('#tree' => TRUE);
      $form[$field['field_name']]['vnames'] = array(
        '#type' => 'select',
        '#title' => t($field['widget']['label']),
        '#default_value' => $node_field['default vnames'],
        '#multiple' => $field['multiple'],
        '#options' => $options,
        '#required' => $field['required'],
        '#description' => $field['widget']['description'],
      );

      $form[$field['field_name']]['vargs'] = array(
        '#type' => 'textarea',
        '#title' => 'arguments',
        '#default_value' => $node_field[0]['vargs'], // all views share args (for now ...)
        '#required' => false,
        '#description' => t('Provide a comma separated list of arguments to pass to the view. You may use %nid for the node id of the current node. %author for the node author and %viewer for user viewing the node. These arguments will be passed to EACH selected view.'),
      );

      return $form;

    case 'process form values':
      if ($field['multiple']) {
        $items = $node_field['vnames'];
        foreach($items as $item) {
          $node_field[] = array (
            'vname' => $item,
            'vargs' => $node_field['vargs'],
          );
        }
      }
      else {
        $node_field[0]['vname'] = $node_field['vnames'];
        $node_field[0]['vargs'] = $node_field['vargs'];
      }
      // Remove the widget's data representation so it isn't saved.
      unset($node_field['vnames']);
      unset($node_field['vargs']);
      
  }
}

/*** Private functions ***/

/**
 * Prepare a list of views for selection.
 */
function _viewfield_potential_references($field) {
  $options = array();
  include_once(drupal_get_path('module', 'views') . '/views_cache.inc');
  $default_views = _views_get_default_views();

  $res = db_query("SELECT name FROM {view_view} ORDER BY name");
  while ($view = db_fetch_object($res)) {
    $options[$view->name] = $view->name; 
  }
  
  if(is_array($default_views)) {
    foreach($default_views as $key => $view) {
      $options[$key] = $view->name;
    }
  }
  
  return $options;
}

/**
 * Functions for manipulating a global stack of nids. This prevents us from recursively
 * building a node, with a view, with the node, with the view.... etc
 */
function _viewfield_nodestack_push($nid) {
  global $viewfield_stack;
  if (!isset($viewfield_stack)) {
    $_GLOBAL['viewfield_stack'] = array();
    global $viewfield_stack;
  }
  
  $viewfield_stack[] = $nid;
  
}

function _viewfield_nodestack_pop() {
  global $viewfield_stack;
  return array_pop($viewfield_stack);
}

/** 
 * Implementation of hook_db_rewrite_sql
 *
 * Prevent views from loading the node containing the view.
 */
function viewfield_db_rewrite_sql($query, $primary_table, $primary_field, $args) {
  global $viewfield_stack;
  if (!empty($viewfield_stack)) {
    if ($primary_field == 'nid') {
      $return['where'] = "$primary_table.nid NOT IN (" . implode(',', $viewfield_stack). ')';
      return $return;
    }
  }
}