<?php
require_once './Inflector.php';
require_once './Database.php';
require_once './DatabaseQuery.php';
require_once './DataMapperManager.php';

abstract class DataMapper
{
  protected $db;
  protected $manager;
  protected $tableName;
  protected $primaryKeyName;
  protected $tableColumnNames;

  public function __construct(DataMapperManager $manager)
  {
    $this->db = $manager->getDatabase();
    $this->manager = $manager;
    
    $this->configure();
  }
  
  protected function createObjectsFromRows($rows)
  {
    $objects = array();
    foreach ($rows as $row)
      $objects[] = $this->createObjectFromRow($row);
    return $objects;
  }

  public function save(DataObject $object)
  {
    if ($this->getPrimaryKey($object) === null)
      $this->insert($object);
    else
      $this->update($object);
  }
  
  public function fetchByPrimaryKey($primaryKey)
  {
    $sql = $this->getQuery()->where("$this->primaryKeyName = ?", $primaryKey)->renderSelectSql();
    $row = $this->db->fetchRow($sql, Database::FETCH_TYPE_ROW);
    if ($row !== null)
      return $this->createObjectFromRow($row); // TODO use $startColumn
    return null;
  }
  
  protected function insert(DataObject $object)
  {
    $this->db->insert($this->tableName, $this->createAssocFromObject($object));
    $this->setPrimaryKey($object, $this->db->insert_id);
  }
  
  protected function update(DataObject $object)
  {
    $where = $this->db->quoteInto("$this->primaryKeyName = ?", $this->getPrimaryKey($object));
    $this->db->update($this->tableName, $this->createAssocFromObject($object), $where);
  }
  
  public function delete(DataObject $object)
  {
    $where = $this->db->quoteInto("$this->primaryKeyName = ?", $this->getPrimaryKey($object));
    $this->db->delete($this->tableName, $where);
  }

  public function createObjectFromRow(array $row, $startColumn = 0)
  {
    $object = $this->createObject();
    $this->hydrateObject($object, $row, $startColumn);
    return $object;
  }
  
  public function getTableColumnNames()
  {
    return $this->tableColumnNames;
  }

  public function getTableName()
  {
    return $this->tableName;
  }
  
  public function getQuery()
  {
    $query = new DatabaseQuery($this->db);
    $query->from($this->tableName, $this->tableColumnNames);
    return $query;
  }
  
  abstract public function configure();

  abstract protected function getPrimaryKey(DataObject $object);
  abstract protected function setPrimaryKey(DataObject $object, $primaryKey);

  abstract public function createObject();
  
  abstract public function createAssocFromObject(DataObject $object);
  abstract public function hydrateObject(DataObject $object, array $row, $startColumn = 0);
}

interface DataObject
{
}