<?php
$dsn = require '.dbconfig.inc.php';
$Db = new DB($dsn);

class DB
{
	public $dbh;

	function __construct($config, $options = [])
	{
		$options += [
			PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
			PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ,
		];
		$this->dbh = new PDO($config, NULL, NULL, $options);
	}

	function query($sql, $params = [])
	{
		$stmt = $this->dbh->prepare($sql);
		$stmt->execute($params);
		return $stmt;
	}

	function _value($val, &$params)
	{
		if (is_array($val)) {
			$sql = array_shift($val);
			$params = array_merge($params, $val);
			return $sql;
		}
		elseif (is_bool($val)) {
			return $val ? 'TRUE' : 'FALSE';
		}

		$params[] = $val;
		return '?';
	}

	function set($table, $row, $filter = NULL)
	{
		$params = [];
		if (is_null($filter)) {
			$cols = [];
			foreach ($row as $col => $val) {
				$cols[] = $this->_value($val, $params);
			}
			$sql = sprintf('INSERT INTO %s (%s) VALUES (%s)',
				'"'.$table.'"',
				implode(', ', array_keys($row)),
				implode(', ', $cols)
			);
		}
		else {
			$sql = 'UPDATE "'.$table.'"';
			$cols = [];
			foreach ($row as $col => $val) {
				$cols[] = $col . ' = ' . $this->_value($val, $params);
			}

			$sql .= ' SET ' . implode(', ', $cols);
			if (is_array($filter)) {
				$sql .= ' WHERE ' . array_shift($filter);
				$params = array_merge($params, $filter);
			}
			else {
				$sql .= ' ' . $filter;
			}
		}
		$sql .= ' RETURNING *';
		return $this->query($sql, $params);
	}
}