<?php

namespace alveolata\database;

// require_once(DIR_ALVEOLATA . '/definitions.php');
require_once(DIR_ALVEOLATA . '/report/functions.php');
require_once(DIR_ALVEOLATA . '/log/functions.php');
require_once(DIR_ALVEOLATA . '/sql/functions.php');


/**
 * @author Christian Fraß <frass@greenscale.de>
 * requires PHP module "pgsql" (Debian package name "php-pgsql")
 */
class struct_subject_postgresql {
	
	/**
	 * @var string
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public $host;
	
	
	/**
	 * @var int
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public $port;
	
	
	/**
	 * @var string
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public $schema;
	
	
	/**
	 * @var string
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public $username;
	
	
	/**
	 * @var string
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public $password;
	
	
	/**
	 * @author Christian Fraß <frass@greenscale.de>
	 */
	public function __construct(
		string $host,
		int $port,
		string $schema,
		string $username,
		string $password
	)
	{
		$this->host = $host;
		$this->port = $port;
		$this->schema = $schema;
		$this->username = $username;
		$this->password = $password;
	}
	
}


/**
 * @author Christian Fraß <frass@greenscale.de>
 */
function postgresql_make(
	string $host,
	int $port,
	string $schema,
	string $username,
	string $password
) : struct_subject_postgresql
{
	return (
		new struct_subject_postgresql(
			$host,
			$port,
			$schema,
			$username,
			$password
		)
	);
}


/**
 * @return string
 * @author Christian Fraß <frass@greenscale.de>
 */
function postgresql_terminal_autoincrement(
) : string
{
	return 'AUTO_INCREMENT';
}


/**
 * @return string
 * @author Christian Fraß <frass@greenscale.de>
 */
function postgresql_boilerplate_field_definition_for_integer_primary_key_with_auto_increment(
) : string
{
	return 'SERIAL PRIMARY KEY';
}


/**
 * @param struct_subject_postgresql $subject
 * @param string $template
 * @param array $arguments
 * @return array
 * @author Christian Fraß <frass@greenscale.de>
 */
function postgresql_query(
	struct_subject_postgresql $subject,
	string $template,
	array $arguments
) : array
{
	$connection = \pg_connect(
		sprintf(
			'host=%s port=%d user=%s password=%s dbname=%s',
			$subject->host,
			$subject->port,
			$subject->username,
			$subject->password,
			$subject->schema
		)
	);
	// \pg_set_client_encoding($connection, \UNICODE);
	\pg_query($connection, "SET client_encoding TO 'UNICODE'");
	$template_adjusted = $template;
	$arguments_adjusted = [];
	$counter = 0;
	foreach ($arguments as $key => $value) {
		$pattern = \sprintf(':%s', $key);
		$replacement = \sprintf('$%d', $counter+1);
		$counter += 1;
		$template_adjusted = str_replace($pattern, $replacement, $template_adjusted);
		\array_push($arguments_adjusted, $value);
	}
	$report = \alveolata\report\make(
		'postgresl_query',
		[
			'template' => $template_adjusted,
			'arguments' => $arguments,
		]
	);
	\alveolata\log\debug_($report);
	$result = \pg_query_params($connection, $template_adjusted, $arguments_adjusted);
	if ($result === false) {
		$report = \alveolata\report\make(
			'postgresl_query_failed',
			[
				'template' => $template_adjusted,
				'arguments' => $arguments_adjusted,
			]
		);
		throw (\alveolata\report\as_exception($report));
	}
	else {
		// $status = \pg_result_status($result, \PGSQL_STATUS_STRING);
		$status = \pg_result_status($result, \PGSQL_STATUS_LONG);
		switch ($status) {
			default: {
				$report = \alveolata\report\make(
					'postgresl_query_bad_result',
					[
						'template' => $template_adjusted,
						'arguments' => $arguments_adjusted,
						'status' => $status,
					]
				);
				throw (\alveolata\report\as_exception($report));
				break;
			}
			case \PGSQL_COMMAND_OK:
			case \PGSQL_TUPLES_OK: {
				$id_raw = \pg_last_oid($result);
				return [
					'rows' => \pg_fetch_all($result, \PGSQL_ASSOC),
					'id' => (($id_raw === false) ? null : $id_raw),
					'affected' => \pg_affected_rows($result),
				];
				break;
			}
		}
	}
}

?>