<?php

  namespace Sabre\DAVACL\PrincipalBackend;
  
  use Sabre\DAV;
  use Sabre\DAVACL;

  /**
   * PDO principal backend
   *

   *

   * This backend assumes all principals are in a single collection. The default collection

   * is 'principals/', but this can be overriden.
   *

   * @copyright Copyright (C) 2007-2014 fruux GmbH (https://fruux.com/).
   * @author Evert Pot (http://evertpot.com/)
   * @license http://sabre.io/license/ Modified BSD License

   */

  class PDO extends AbstractBackend {

  
      /**
       * pdo
       *
       * @var PDO
       */
      protected $pdo;
  
      /**
       * PDO table name for 'principals'
       *
       * @var string
       */
      protected $tableName;
  
      /**
       * PDO table name for 'group members'
       *
       * @var string
       */
      protected $groupMembersTableName;
  
      /**
       * A list of additional fields to support
       *
       * @var array
       */
      protected $fieldMap = array(
  
          /**
           * This property can be used to display the users' real name.
           */
          '{DAV:}displayname' => array(
              'dbField' => 'displayname',
          ),
  
          /**
           * This property is actually used by the CardDAV plugin, where it gets
           * mapped to {http://calendarserver.orgi/ns/}me-card.
           *
           * The reason we don't straight-up use that property, is because
           * me-card is defined as a property on the users' addressbook
           * collection.
           */
          '{http://sabredav.org/ns}vcard-url' => array(
              'dbField' => 'vcardurl',
          ),
          /**
           * This is the users' primary email-address.
           */
          '{http://sabredav.org/ns}email-address' => array(
              'dbField' => 'email',
          ),
      );
  
      /**
       * Sets up the backend.
       *
       * @param PDO $pdo
       * @param string $tableName
       * @param string $groupMembersTableName
       */

      public function __construct(\PDO $pdo, $tableName = 'principals', $groupMembersTableName = 'groupmembers') {

  
          $this->pdo = $pdo;
          $this->tableName = $tableName;
          $this->groupMembersTableName = $groupMembersTableName;
  
      }
  
  
      /**
       * Returns a list of principals based on a prefix.
       *
       * This prefix will often contain something like 'principals'. You are only
       * expected to return principals that are in this base path.
       *
       * You are expected to return at least a 'uri' for every user, you can
       * return any additional properties if you wish so. Common properties are:
       *   {DAV:}displayname
       *   {http://sabredav.org/ns}email-address - This is a custom SabreDAV
       *     field that's actualy injected in a number of other properties. If
       *     you have an email address, use this property.
       *
       * @param string $prefixPath
       * @return array
       */
      public function getPrincipalsByPrefix($prefixPath) {
  
          $fields = array(
              'uri',
          );
  
          foreach($this->fieldMap as $key=>$value) {
              $fields[] = $value['dbField'];
          }
          $result = $this->pdo->query('SELECT '.implode(',', $fields).'  FROM '. $this->tableName);
  
          $principals = array();

          while($row = $result->fetch(\PDO::FETCH_ASSOC)) {

  
              // Checking if the principal is in the prefix

              list($rowPrefix) = DAV\URLUtil::splitPath($row['uri']);

              if ($rowPrefix !== $prefixPath) continue;
  
              $principal = array(
                  'uri' => $row['uri'],
              );
              foreach($this->fieldMap as $key=>$value) {
                  if ($row[$value['dbField']]) {
                      $principal[$key] = $row[$value['dbField']];
                  }
              }
              $principals[] = $principal;
  
          }
  
          return $principals;
  
      }
  
      /**
       * Returns a specific principal, specified by it's path.
       * The returned structure should be the exact same as from
       * getPrincipalsByPrefix.
       *
       * @param string $path
       * @return array
       */
      public function getPrincipalByPath($path) {
  
          $fields = array(
              'id',
              'uri',
          );
  
          foreach($this->fieldMap as $key=>$value) {
              $fields[] = $value['dbField'];
          }
          $stmt = $this->pdo->prepare('SELECT '.implode(',', $fields).'  FROM '. $this->tableName . ' WHERE uri = ?');
          $stmt->execute(array($path));

          $row = $stmt->fetch(\PDO::FETCH_ASSOC);

          if (!$row) return;
  
          $principal = array(
              'id'  => $row['id'],
              'uri' => $row['uri'],
          );
          foreach($this->fieldMap as $key=>$value) {
              if ($row[$value['dbField']]) {
                  $principal[$key] = $row[$value['dbField']];
              }
          }
          return $principal;
  
      }
  
      /**
       * Updates one ore more webdav properties on a principal.
       *
       * The list of mutations is supplied as an array. Each key in the array is
       * a propertyname, such as {DAV:}displayname.
       *
       * Each value is the actual value to be updated. If a value is null, it
       * must be deleted.
       *
       * This method should be atomic. It must either completely succeed, or
       * completely fail. Success and failure can simply be returned as 'true' or
       * 'false'.
       *
       * It is also possible to return detailed failure information. In that case
       * an array such as this should be returned:
       *
       * array(
       *   200 => array(
       *      '{DAV:}prop1' => null,
       *   ),
       *   201 => array(
       *      '{DAV:}prop2' => null,
       *   ),
       *   403 => array(
       *      '{DAV:}prop3' => null,
       *   ),
       *   424 => array(
       *      '{DAV:}prop4' => null,
       *   ),
       * );
       *
       * In this previous example prop1 was successfully updated or deleted, and
       * prop2 was succesfully created.
       *
       * prop3 failed to update due to '403 Forbidden' and because of this prop4
       * also could not be updated with '424 Failed dependency'.
       *
       * This last example was actually incorrect. While 200 and 201 could appear
       * in 1 response, if there's any error (403) the other properties should
       * always fail with 423 (failed dependency).
       *
       * But anyway, if you don't want to scratch your head over this, just
       * return true or false.
       *
       * @param string $path
       * @param array $mutations
       * @return array|bool
       */
      public function updatePrincipal($path, $mutations) {
  
          $updateAble = array();
          foreach($mutations as $key=>$value) {
  
              // We are not aware of this field, we must fail.
              if (!isset($this->fieldMap[$key])) {
  
                  $response = array(
                      403 => array(
                          $key => null,
                      ),
                      424 => array(),
                  );
  
                  // Adding the rest to the response as a 424
                  foreach($mutations as $subKey=>$subValue) {
                      if ($subKey !== $key) {
                          $response[424][$subKey] = null;
                      }
                  }
                  return $response;
              }
  
              $updateAble[$this->fieldMap[$key]['dbField']] = $value;
  
          }
  
          // No fields to update
          $query = "UPDATE " . $this->tableName . " SET ";
  
          $first = true;
          foreach($updateAble as $key => $value) {
              if (!$first) {
                  $query.= ', ';
              }
              $first = false;
              $query.= "$key = :$key ";
          }
          $query.='WHERE uri = :uri';
          $stmt = $this->pdo->prepare($query);
          $updateAble['uri'] =  $path;
          $stmt->execute($updateAble);
  
          return true;
  
      }
  
      /**
       * This method is used to search for principals matching a set of
       * properties.
       *
       * This search is specifically used by RFC3744's principal-property-search
       * REPORT. You should at least allow searching on
       * http://sabredav.org/ns}email-address.
       *
       * The actual search should be a unicode-non-case-sensitive search. The
       * keys in searchProperties are the WebDAV property names, while the values
       * are the property values to search on.
       *
       * If multiple properties are being searched on, the search should be
       * AND'ed.
       *
       * This method should simply return an array with full principal uri's.
       *
       * If somebody attempted to search on a property the backend does not
       * support, you should simply return 0 results.
       *
       * You can also just return 0 results if you choose to not support
       * searching at all, but keep in mind that this may stop certain features
       * from working.
       *
       * @param string $prefixPath
       * @param array $searchProperties
       * @return array
       */
      public function searchPrincipals($prefixPath, array $searchProperties) {
  
          $query = 'SELECT uri FROM ' . $this->tableName . ' WHERE 1=1 ';
          $values = array();
          foreach($searchProperties as $property => $value) {
  
              switch($property) {
  
                  case '{DAV:}displayname' :
                      $query.=' AND displayname LIKE ?';
                      $values[] = '%' . $value . '%';
                      break;
                  case '{http://sabredav.org/ns}email-address' :
                      $query.=' AND email LIKE ?';
                      $values[] = '%' . $value . '%';
                      break;
                  default :
                      // Unsupported property
                      return array();
  
              }
  
          }
          $stmt = $this->pdo->prepare($query);
          $stmt->execute($values);
  
          $principals = array();

          while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {

  
              // Checking if the principal is in the prefix

              list($rowPrefix) = DAV\URLUtil::splitPath($row['uri']);

              if ($rowPrefix !== $prefixPath) continue;
  
              $principals[] = $row['uri'];
  
          }
  
          return $principals;
  
      }
  
      /**
       * Returns the list of members for a group-principal
       *
       * @param string $principal
       * @return array
       */
      public function getGroupMemberSet($principal) {
  
          $principal = $this->getPrincipalByPath($principal);

          if (!$principal) throw new DAV\Exception('Principal not found');

  
          $stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM '.$this->groupMembersTableName.' AS groupmembers LEFT JOIN '.$this->tableName.' AS principals ON groupmembers.member_id = principals.id WHERE groupmembers.principal_id = ?');
          $stmt->execute(array($principal['id']));
  
          $result = array();

          while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {

              $result[] = $row['uri'];
          }
          return $result;
  
      }
  
      /**
       * Returns the list of groups a principal is a member of
       *
       * @param string $principal
       * @return array
       */
      public function getGroupMembership($principal) {
  
          $principal = $this->getPrincipalByPath($principal);

          if (!$principal) throw new DAV\Exception('Principal not found');

  
          $stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM '.$this->groupMembersTableName.' AS groupmembers LEFT JOIN '.$this->tableName.' AS principals ON groupmembers.principal_id = principals.id WHERE groupmembers.member_id = ?');
          $stmt->execute(array($principal['id']));
  
          $result = array();

          while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {

              $result[] = $row['uri'];
          }
          return $result;
  
      }
  
      /**
       * Updates the list of group members for a group principal.
       *
       * The principals should be passed as a list of uri's.
       *
       * @param string $principal
       * @param array $members
       * @return void
       */
      public function setGroupMemberSet($principal, array $members) {
  
          // Grabbing the list of principal id's.
          $stmt = $this->pdo->prepare('SELECT id, uri FROM '.$this->tableName.' WHERE uri IN (? ' . str_repeat(', ? ', count($members)) . ');');
          $stmt->execute(array_merge(array($principal), $members));
  
          $memberIds = array();
          $principalId = null;

          while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {

              if ($row['uri'] == $principal) {
                  $principalId = $row['id'];
              } else {
                  $memberIds[] = $row['id'];
              }
          }

          if (!$principalId) throw new DAV\Exception('Principal not found');

  
          // Wiping out old members
          $stmt = $this->pdo->prepare('DELETE FROM '.$this->groupMembersTableName.' WHERE principal_id = ?;');
          $stmt->execute(array($principalId));
  
          foreach($memberIds as $memberId) {
  
              $stmt = $this->pdo->prepare('INSERT INTO '.$this->groupMembersTableName.' (principal_id, member_id) VALUES (?, ?);');
              $stmt->execute(array($principalId, $memberId));
  
          }
  
      }
  
  }