<?php namespace Illuminate\Database\Connectors;

use PDO;

class PostgresConnector extends Connector implements ConnectorInterface {

	/**
	 * The default PDO connection options.
	 *
	 * @var array
	 */
	protected $options = array(
		PDO::ATTR_CASE => PDO::CASE_NATURAL,
		PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
		PDO::ATTR_ORACLE_NULLS => PDO::NULL_NATURAL,
		PDO::ATTR_STRINGIFY_FETCHES => false,
	);

	/**
	 * Establish a database connection.
	 *
	 * @param  array  $config
	 * @return \PDO
	 */
	public function connect(array $config)
	{
		// First we'll create the basic DSN and connection instance connecting to the
		// using the configuration option specified by the developer. We will also
		// set the default character set on the connections to UTF-8 by default.
		$dsn = $this->getDsn($config);

		$options = $this->getOptions($config);

		$connection = $this->createConnection($dsn, $config, $options);

		$charset = $config['charset'];

		$connection->prepare("set names '$charset'")->execute();

		// Next, we will check to see if a timezone has been specified in this config
		// and if it has we will issue a statement to modify the timezone with the
		// database. Setting this DB timezone is an optional configuration item.
		if (isset($config['timezone']))
		{
			$timezone = $config['timezone'];

			$connection->prepare("set time zone '$timezone'")->execute();
		}

		// Unlike MySQL, Postgres allows the concept of "schema" and a default schema
		// may have been specified on the connections. If that is the case we will
		// set the default schema search paths to the specified database schema.
		if (isset($config['schema']))
		{
			$schema = $config['schema'];

			$connection->prepare("set search_path to \"{$schema}\"")->execute();
		}

		return $connection;
	}

	/**
	 * Create a DSN string from a configuration.
	 *
	 * @param  array   $config
	 * @return string
	 */
	protected function getDsn(array $config)
	{
		// First we will create the basic DSN setup as well as the port if it is in
		// in the configuration options. This will give us the basic DSN we will
		// need to establish the PDO connections and return them back for use.
		extract($config);

		$host = isset($host) ? "host={$host};" : '';

		$dsn = "pgsql:{$host}dbname={$database}";

		// If a port was specified, we will add it to this Postgres DSN connections
		// format. Once we have done that we are ready to return this connection
		// string back out for usage, as this has been fully constructed here.
		if (isset($config['port']))
		{
			$dsn .= ";port={$port}";
		}

		if (isset($config['sslmode']))
		{
			$dsn .= ";sslmode={$sslmode}";
		}

		return $dsn;
	}

}
