<?php
// $Id: user_relationships_api.module,v 1.1.4.4 2008-09-15 20:14:01 alexk Exp $

/**
 *
 * This file contains utility functions for the User Relationships module
 * Please consult either the other files for public functions
 *
 */

define('UR_OK', 0x0);
define('UR_BANNED', 0x1);


// Load all needed files
$modulepath = drupal_get_path('module', 'user_relationships_api');
require_once("{$modulepath}/user_relationships_api.api.inc");


/**
 *  Invoke hook_user_relationships() or hook_user_relationships_type()
 *  Just a helper that allows us to pass the relationship or relationship_type
 *  object by reference
 */
function _user_relationships_invoke($type, &$relationship, $is_type = FALSE) {
  $hook = 'user_relationships'.($is_type ? '_type' : '');

  foreach (module_list() as $module) {
    $function = "{$module}_{$hook}";
    if (function_exists($function)) {
      $function($type, $relationship);
    }
  }
}


/**
 * Helper function to generate queries from a list of parameters
 */
function _user_relationships_generate_query($param = array(), $options = array()) {
  extract($options, EXTR_SKIP);

  // Turn the conditions into a query.
  foreach ($param as $key => $value) {
    if (!isset($value)) { continue; }

    $operator = _user_relationship_process_query_argument($key, $value);

    switch ($key) {
    case 'between':
      $cond[] =
        "((ur.requester_id {$operator[0]} AND ur.requestee_id {$operator[1]})".
        ' OR '.
        "(ur.requestee_id {$operator[0]} AND ur.requester_id {$operator[1]}))";
      $arguments[] = $value[0];
      $arguments[] = $value[1];
      $arguments[] = $value[0];
      $arguments[] = $value[1];
      break;

    case 'user':
      $cond[] = "(ur.requester_id {$operator} OR ur.requestee_id {$operator})";
      $arguments[] = $value;
      $arguments[] = $value;
      break;

    default:
      $types_cols = array('name','plural_name','is_oneway','requires_approval','expires_val');
      $cond[] = "%s.%s {$operator}";
      $arguments[] = !in_array($key, $types_cols) ? 'ur' : 'urt';
      $arguments[] = $key;
      $arguments[] = $value;
    }
  }

  $selects = array('DISTINCT ur.rid', 'ur.*', 'urt.*');
  $joins = array('INNER JOIN {user_relationship_types} urt USING ( rtid )');

  // We wont need anything after this point for the count SQL
  $count_joins = implode(' ', $joins);

  if ($include_user_info) {
    $selects = array_merge($selects, array(
      'requesters.name AS requester_name',
      'requestees.name AS requestee_name',
      'requesters.mail AS requester_mail',
      'requestees.mail AS requestee_mail',
      'requesters.data AS requester_data',
      'requestees.data AS requestee_data',
      'requesters.picture AS requester_picture',
      'requestees.picture AS requestee_picture',
    ));

    $joins = array_merge($joins, array(
      'INNER JOIN {users} requesters ON ur.requester_id = requesters.uid',
      'INNER JOIN {users} requestees ON ur.requestee_id = requestees.uid'
    ));
  }

  $selects = implode(',', $selects);
  $joins = implode(' ', $joins);

  $cond = $cond ? 'WHERE '.implode(' AND ', $cond) : '';

  $extra = array();
  if (!empty($order)) {
    $extra[] = "ORDER BY {$order}";
  }
  if (!empty($limit)) {
    $extra[] = "LIMIT {$limit}";
  }
  $extra = is_array($extra) ? implode(' ', $extra) : $extra;

  return array(
    'query'     => "SELECT {$selects} FROM {user_relationships} ur {$joins} {$cond} GROUP BY rid {$extra}",
    'count'     => "SELECT COUNT(DISTINCT rid) AS count FROM {user_relationships} ur {$count_joins} {$cond}",
    'arguments' => $arguments,
  );
}


/** 
 * Helper function to process the various argument types allowed
 */
function _user_relationship_process_query_argument($key, &$value) {
  if ($key == 'between') {
    return array(
      _user_relationship_process_query_argument(NULL, $value[0]),
      _user_relationship_process_query_argument(NULL, $value[1]),
    );
  }

  if (is_array($value)) {
    if (count($value) == 1) {
      $value = array_shift($value);
      return _user_relationship_process_query_argument($key, $value);
    }
    else {
      $type = is_numeric(current($value)) ? 'int' : 'varchar';
      return 'IN ('.db_placeholders($value, $type).')';
    }
  }
  else if (is_numeric($value) || is_bool($value)) {
    $value = (int)$value;
    return '= %d';
  }
  else if (preg_match('/([<>=]{1,2})\s*(.+)/', $value, $matches)){
    $marker = "'%s'";
    $value = $matches[3];

    if (is_numeric($value)) {
      $marker = '%d';
      $value = (int)$value;
    }

    return "{$matches[1]} {$marker}";
  }
  else {
    return "= '%s'";
  }
}


/*********************
 *       HOOKS
 *********************/

/**
 * Implementation of hook_perm().
 */
function user_relationships_api_perm() {
  return array(
    'can have relationship',
  );
}


/**
 * Implementation of hook_user().
 */
function user_relationships_api_user($type, &$edit, &$account, $category = NULL) {
  if ($type == 'delete') {
    db_query("DELETE FROM {user_relationships} WHERE requester_id = %d OR requestee_id = %d", $account->uid, $account->uid);
  }
}


/**
 * Implementation of hook_cron().
 */
function user_relationships_api_cron() {
  $now = time();

  // only expire relationships once a day
  $last_cron = variable_get('user_relationships_last_expire', 0);
  if ($now >  $last_cron + (24 * 60 * 60)) {
    return FALSE;
  }

  switch ($GLOBALS['db_type']) {
  case 'mysql':
  case 'mysqli':
    db_query(
      " DELETE ur
        FROM user_relationships ur 
          INNER JOIN user_relationship_types urt USING ( rtid )
        WHERE ur.approved = 0 
          AND urt.expires_val > 0 
          AND %d > (ur.updated_at + (urt.expires_val * 24 * 60 *60))",
      $now
    );
    break;
  }

  // remember when we last expired relationships
  variable_set('user_relationships_last_expire', $now);
  return TRUE;
}