ORM/Model.php

<?php

/**
 * Created by PhpStorm.
 * User: root
 * Date: 31.07.18
 * Time: 10:49
 */
require_once "DB.php";
require_once "Comment.php";
require_once "User.php";
require_once "Post.php";

abstract class Model
{
    public static $objects = [];

    public $tableName;
    public $pkName;
    public $connection;
    public $entry;
    protected $dirty;
    protected $objDescTable;
    public static $descTable;

    public function __construct(array $entry = [])
    {
        $this->tableName = strtolower(get_called_class()) . "s";
        $this->pkName = static::getPkName();
        $this->connection = DB::getConnection();
        $this->entry = $entry;
        $this->dirty = false;
        $this->objDescTable = self::descTable();
    }

    public static function getByPk(int $pk)
    {
        if (isset(self::$objects[get_called_class() . "." . $pk])) return self::$objects[get_called_class() . "." . $pk];
        $query =
            "SELECT * FROM " . strtolower(get_called_class()) . "s" .
            " WHERE " . static::getPkName() . " = " . $pk;
        $connect = DB::getConnection();
        $result = $connect->query($query)->fetchAll(PDO::FETCH_ASSOC);
        return new static($result[0]);
    }

    protected static function descTable(): array
    {
        $query = "DESC " . strtolower(get_called_class()) . "s";
        $connect = DB::getConnection();
        $result = $connect->query($query)->fetchAll(PDO::FETCH_ASSOC);
        return $result;
    }

    protected static function getPkName(): string
    {
        foreach (static::$descTable ?? static::descTable() as $value) {
            if ($value["Key"] === "PRI") return $value["Field"];
        }
    }

    public function __get($name)
    {
        foreach ($this->entry as $key => $value) {
            if ($key === $name) return $value;
        }
    }

    public function __set($name, $setValue)
    {
        foreach ($this->objDescTable as $value) {
            if (strtolower($value["Field"]) === $name) {
                $oldValue = $this->entry[$name] ?? "";
                $this->entry[$name] = $setValue;
                if ($this->entry[$name] !== $oldValue) $this->dirty = true;
            }
        }
    }

    protected function getPreparedArguments()
    {
        $preparedRequest = [];
        foreach ($this->entry as $key => $value) {
            if ($key === $this->pkName) continue;
            $preparedRequest[] = $key . " = :" . $key;
        }
        return " SET " . implode(", ", $preparedRequest) . " ";
    }

    protected function getPreparedEntry()
    {
        $array = [];
        foreach ($this->entry as $key => $value) {
            if ($key === $this->pkName) continue;
            $array[$key] = $value;
        }
        return $array;
    }

    public function save()
    {
        $identityNewEntry = $this->entry[$this->pkName] ?? false;
        $operation = $identityNewEntry ? "UPDATE " : "INSERT INTO ";
        $condition = $operation === "UPDATE " ? " WHERE {$this->pkName} = {$this->entry["id"]}" : "";
        $query = $operation . $this->tableName . $this->getPreparedArguments() . $condition;
        $sth = $this->connection->prepare($query, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
        $sth->execute($this->getPreparedEntry());
        if (!$identityNewEntry) $this->entry[$this->pkName] = $this->connection->lastInsertId();
        Model::$objects[get_called_class() . "." . $this->entry[$this->pkName]] = $this;
        $this->dirty = false;
    }
}