Шедевральная хуйня

<?php

class DB {
    protected $pdo;

    protected function __construct() {
        $info = config('db');
        foreach (array('dsn', 'user', 'password', 'args') as $key) {
            if (!isset($info[$key])) {
                $info[$key] = null;
            }
        }
        try {
            $this->pdo = new PDO($info['dsn'], $info['user'], $info['password'], $info['args']);
        }
        catch (PDOException $e) {
            die('Connection failed: ' . $e->getMessage());
        }
        $this->query('SET NAMES utf8');
    }

    public static function i() {
        static $db;
        if (!$db) {
            $db = new self;
        }
        return $db;
    }

    public function query($sql, $bindings = null) {
        print dump($sql);
        $stmt = $this->pdo->prepare($sql);
        $stmt->execute($bindings);
        return $stmt;
    }

    public function insert($table, $data) {
        $sql = "INSERT INTO $table";
        $values = array_values($data);
        if ($values != $data) {
            $fields = array_keys($data);
            $sql .= ' (' . implode(',', $fields) . ')';
        }
        $sql .= ' VALUES (' . rtrim(str_repeat('?,', count($data)), ',') . ')';
        $this->query($sql, $values);
        $id = $this->pdo->lastInsertId();
        return $id;
    }

    public function select($from, $what = '*', $criteria = 0, $limit = 0, $offset = 0, $order = 0, $bindings = null) {
        $sql = "SELECT $what FROM $from";
        $sql .= $this->where($criteria, $bindings);
        if ($order) {
            $sql .= " ORDER BY $order";
        }
        if ($limit) {
            $sql .= " LIMIT $offset,$limit";
        }
        $stmt = $this->query($sql, $bindings);
        return $stmt;
    }

    public function selectRow($from, $what = '*', $criteria = 0, $order = 0, $bindings = null) {
        return $this->select($from, $what, $criteria, 0, 0, $order, $bindings);
    }

    public function get($from, $what = '*', $criteria = 0, $limit = 0, $offset = 0, $order = 0, $bindings = null) {
        $stmt = $this->select($from, $what, $criteria, $limit, $offset, $order, $bindings);
        return $stmt->fetchAll(PDO::FETCH_ASSOC);
    }

    public function getRow($from, $what = '*', $criteria = 0, $order = 0, $bindings = null) {
        $stmt = $this->selectRow($from, $what, $criteria, $order, $bindings);
        return $stmt->fetch(PDO::FETCH_ASSOC);
    }

    public function getValue($from, $field, $criteria = 0, $order = 0, $bindings = null) {
        $stmt = $this->selectRow($from, $field, $criteria, $order, $bindings);
        return $stmt->fetchColumn();
    }

    public function count($table, $criteria = 0, $bindings = null) {
        return (int) $this->getValue($table, 'COUNT(*)', $criteria, 0, $bindings);
    }

    // можно использовать только именованные плейсхолдеры
    public function update($what, $data, $criteria = 0, $bindings = array()) {
        $sql = "UPDATE $what SET ";
        $parts = array();
        foreach ($data as $k => $v) {
            $bindings[":$k"] = $v;
            $parts[] = "$k=:$k";
        }
        $sql .= implode(',', $parts) . $this->where($criteria, $bindings);
        $stmt = $this->query($sql, $bindings);
        return $stmt->rowCount();
    }

    public function delete($from, $criteria, $bindings = null) {
        $sql = "DELETE FROM $from" . $this->where($criteria, $bindings);
        $stmt = $this->query($sql, $bindings);
        return $stmt->rowCount();
    }

    protected function where($criteria, &$bindings) {
        if (is_array($criteria)) {
            // array('foo' => $foo, 'bar' => $bar);
            // WHERE foo=:foo AND bar=:bar
            $bindings = (array) $bindings;
            $parts = array();
            foreach ($criteria as $k => $v) {
                $bindings[":$k"] = $v;
                $parts[] = "$k=:$k";
            }
            $criteria = implode(' AND ', $parts);
        }
        return $criteria ? " WHERE $criteria" : "";
    }
}