<?php

class PgDatabase {
	private $db = null;

	public function __construct($software=null, $instance=null) {
		if ($software === null && !isset($GLOBALS['ap_software'])) {
			$url = trim($_SERVER['REQUEST_URI'], '/');
			$url = substr($url, 7); // api/vX/
			$ps = explode('/', $url);
			$software = $ps[1];
		}
		if ($software === null && isset($GLOBALS['ap_software']))
			$software = $GLOBALS['ap_software'];

		$config = null;
		if ($instance === null)
			$config = instance_config($software);
		else $config = instance_config($software, $instance);
		if ($config === null) return;

		$this->db = pg_connect(
			' host='.$config['psql_host'].
			' port='.$config['psql_port'].
			' dbname='.$config['psql_db'].
			' user='.$config['psql_username'].
			' password='.$config['psql_password'].
		'') or apiresult(['error' => 'Could not connect to postgres: '.pg_last_error()], 500);
	}

	public function is_ok() {
		return $this->db !== null;
	}

	public function escape($str) {
		return pg_escape_string($this->db, $str);
	}

	public function query($sql) {
		$result = pg_query($this->db, $sql);
		if (!$result) apiresult('The postgres query has failed: '.pg_last_error());
		return $result;
	}

	public function fetch($sql, $cache=null, $only_cached=false) {
		$sql = trim($sql);
		cronjob_db_create__check_cachecfg($GLOBALS['ap_software'],
			$GLOBALS['ap_instance'], $sql, $cache);
		$cache_key = $GLOBALS['ap_software'].$GLOBALS['ap_instance'].$sql;
		if ($cache !== null) {
			$cached = content_cache__get($cache_key);
			if ($cached !== null)
				return $cached;
		}
		if ($only_cached)
			return 'not_cached';
		$result = $this->query($sql);
		$data = pg_fetch_assoc($result);
		if ($cache !== null)
			content_cache__put($cache_key, $cache, $data);
		return $data;
	}

	public function fetch_all($sql, $cache=null, $only_cached=false) {
		$sql = trim($sql);
		cronjob_db_create__check_cachecfg($GLOBALS['ap_software'],
			$GLOBALS['ap_instance'], $sql, $cache);
		$cache_key = $GLOBALS['ap_software'].$GLOBALS['ap_instance'].$sql;
		if ($cache !== null) {
			$cached = content_cache__get($cache_key);
			if ($cached !== null)
				return $cached;
		}
		if ($only_cached)
			return 'not_cached';
		$data = [];
		$result = $this->query($sql);
		while ($line = pg_fetch_array($result, null, PGSQL_ASSOC)) {
			$data []= $line;
		}
		pg_free_result($result);
		if ($cache !== null)
			content_cache__put($cache_key, $cache, $data);
		return $data;
	}

	public function close($result=null) {
		if ($result !== null)
			pg_free_result($result);
		pg_close($this->db);
	}
}