<?php
  /*
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * This software consists of voluntary contributions made by many individuals
   * and is licensed under the MIT license. For more information, see
   * <http://www.doctrine-project.org>.
   */
  
  namespace Doctrine\DBAL\Sharding;
  
  use Doctrine\DBAL\Sharding\ShardChoser\ShardChoser;
  
  /**
   * Shard Manager for the Connection Pooling Shard Strategy
   *
   * @author Benjamin Eberlei <kontakt@beberlei.de>
   */
  class PoolingShardManager implements ShardManager
  {
      private $conn;
      private $choser;
      private $currentDistributionValue;
  
      public function __construct(PoolingShardConnection $conn)
      {
          $params       = $conn->getParams();
          $this->conn   = $conn;
          $this->choser = $params['shardChoser'];
      }
  
      public function selectGlobal()
      {
          $this->conn->connect(0);
          $this->currentDistributionValue = null;
      }
  
      public function selectShard($distributionValue)
      {
          $shardId = $this->choser->pickShard($distributionValue, $this->conn);
          $this->conn->connect($shardId);
          $this->currentDistributionValue = $distributionValue;
      }
  
      public function getCurrentDistributionValue()
      {
          return $this->currentDistributionValue;
      }
  
      public function getShards()
      {
          $params = $this->conn->getParams();
          $shards = array();
  
          foreach ($params['shards'] as $shard) {
              $shards[] = array('id' => $shard['id']);
          }
  
          return $shards;
      }
  
      public function queryAll($sql, array $params, array $types)
      {
          $shards = $this->getShards();
          if (!$shards) {
              throw new \RuntimeException("No shards found.");
          }
  
          $result = array();
          $oldDistribution = $this->getCurrentDistributionValue();
  
          foreach ($shards as $shard) {
              $this->selectShard($shard['id']);
              foreach ($this->conn->fetchAll($sql, $params, $types) as $row) {
                  $result[] = $row;
              }
          }
  
          if ($oldDistribution === null) {
              $this->selectGlobal();
          } else {
              $this->selectShard($oldDistribution);
          }
  
          return $result;
      }
  }