<?php
include_once('NestedSetDbTable/DbAdapter/Interface.php');

include_once('NestedSetDbTable/DbAdapter/Default/Exception.php');

/**
 * Default database adapter.
 *
 * @author Nikola Posa <hide@address.com>
 * @license http://opensource.org/licenses/gpl-3.0.html GNU General Public License
 */
class NestedSetDbTable_DbAdapter_Default implements NestedSetDbTable_DbAdapter_Interface
{
	/**
     * Database connection. Represents PDO instance.
     *
     * @var object|null
     */
    protected $_connection;
	
	/**
     * Fetch mode
     *
     * @var integer
     */
    protected $_fetchMode = PDO::FETCH_ASSOC;
	
	/**
     * Constructor.
     *
	 * Supported params for $options are:
     *   dsn 			- the Data Source Name, or DSN, contains the information required to connect to the database,
     *   username       - the username for the DSN string,
     *   password       - The password for the DSN string,
	 *   driver_options - additional driver-specific connection options.
	 *
	 * @param array Array with custom config options.
     * @return NestedSetDbTable_DbAdapter_Interface
     */
	public function __construct($config)
    {
		if(!$config['dsn']) {
			throw new NestedSetDbTable_DbAdapter_Default_Exception('You must supply DSN string.');
		}
		
		if(!$config['username'] || null === $config['password']) {
			throw new NestedSetDbTable_DbAdapter_Default_Exception('You must supply both connection username and password.');
		}
		
		$this->_connection = new PDO($config['dsn'], $config['username'], $config['password'], $config['driver_options']);
    }
	
	public function setFetchMode($mode)
	{
		$this->_fetchMode = (int)$mode;
	}
	
	/**
	 * NestedSetDbTable_DbAdapter_Interface implementation.
	 */
	 
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
	 * Quotes a value for an SQL query.
	 *
	 * @param string The value that will be quoted.
	 * @return string
	 */
	public function quote($value)
	{
		return $this->_connection->quote($value);
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
	 * Prepares and executes an SQL statement. This method should 
	 * return PDOStatement object.
	 *
	 * @param string SQL statement that can contain placeholders.
	 * @param array An array of data to bind to the placeholders (optional).
	 * @return PDOStatement
	 */
	public function query($sql, $bind = array())
	{
		$stmt = $this->_connection->prepare($sql);
		$stmt->execute($bind);
		
		return $stmt;
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
     * Inserts a row with specified data.
     *
     * @param string Name of the table.
     * @param array Array with data as column-value pairs.
     * @return int The number of affected rows.
     */
	public function insert($tableName, $data)
	{
		$cols = array_keys($data);
        $vals = array_fill(0, count($data), '?');
		
		$sql = "INSERT INTO 
			{$tableName}"
             . ' (' . implode(', ', $cols) . ') '
             . 'VALUES (' . implode(', ', $vals) . ')';
		
		//Execute the statement and return the number of affected rows.
        $stmt = $this->query($sql, array_values($data));
		
		return $stmt->rowCount();
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
     * Updates table rows with specified data, optionally based on 
	 * a SQL WHERE clause.
     *
     * @param string Name of the table.
     * @param array Array with data as column-value pairs.
     * @param string|null UPDATE WHERE clause. (optional)
     * @return int The number of affected rows.
     */
	public function update($tableName, $data, $where = null)
	{
		$set = array();
		foreach (array_keys($data) as $col) {
			$set[] = "{$col} = ?";
		}
		
		$sql = "UPDATE 
             {$tableName}"
             . ' SET ' . implode(', ', $set)
             . (($where != null) ? " WHERE $where" : '');

		//Execute the statement and return the number of affected rows.
        $stmt = $this->query($sql, array_values($data));
		
		return $stmt->rowCount();
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
     * Deletes table rows based on a WHERE clause.
     *
     * @param string Name of the table.
     * @param string|null DELETE WHERE clause. (optional)
     * @return int The number of affected rows.
     */
	public function delete($tableName, $where = null)
	{
		$sql = "DELETE FROM 
			{$tableName}"
             . (($where != null) ? " WHERE $where" : '');

        //Execute the statement and return the number of affected rows.
        $stmt = $this->_connection->query($sql);
        
		return $stmt->rowCount();
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
     * Fetches all SQL result rows as a sequential array. Uses 
	 * current $_fetchMode for this adapter.
     *
     * @param string An SQL SELECT statement.
     * @return array
     */
	public function fetchAll($sql)
	{
		$stmt = $this->_connection->query($sql);
		
		return $stmt->fetchAll($this->_fetchMode);
	}
	
	/**
	 * Required by the NestedSetDbTable_DbAdapter_Interface 
	 * implementation.
     * Fetches the first row of the SQL result. Uses current 
	 * $_fetchMode for this adapter.
     *
     * @param string An SQL SELECT statement.
     * @return array
     */
	public function fetchRow($sql)
	{
		$stmt = $this->_connection->query($sql);
		
		return $stmt->fetch($this->_fetchMode);
	}
}
?>