<?php
/**
 * Universal Object factory ... well kinda :p
 *
 * @author nimmneun
 * @since 06.06.2015 03:07
 */
class Trunk
{
    /**
     * @var object[]
     */
    private $objects = array();

    /**
     * @var array with class dependencies.
     */
    private $dependencies = array(
        'App' => array(
            'Keyword',
            'Check',
            'Config',
            'UniCurl',
        ),
        'Keyword' => array(
            'Database',
            'Validator',
        ),
        'Database' => array(
            'Config',
            'PDO',
        ),
    );

    /**
     * @param string $objectName is case sensitive!
     * @return object
     * @throws TrunkException
     */
    public function get($objectName)
    {
        $dependencies = range(0,2);
        $i = 0;

        if (isset($this->objects[$objectName])
            && $this->objects[$objectName] instanceof $objectName)
        {
            $desiredObject = $this->objects[$objectName];
        }
        else
        {
            try
            {
                if (isset($this->dependencies[$objectName]))
                {
                    foreach ($this->dependencies[$objectName] as $dependencyName)
                    {
                        $dependencies[$i++] = $this->get($dependencyName);
                    }
                }
                $this->objects[$objectName] = $desiredObject = new $objectName($dependencies[0], $dependencies[1], $dependencies[2]);
            }
            catch (Exception $e)
            {
                throw new TrunkException('Unresolvable dependencies: '. $e->getMessage());
                // todo: $this->getComplex($objectName);
            }
        }

        return $desiredObject;
    }
}

class TrunkException extends Exception {}