Config.php

<?php namespace Yusukezzz;

use Illuminate\Filesystem\Filesystem;

class Config implements \ArrayAccess
{
  /**
   * @var array
   */
  protected $items = [];

  /**
   * @var array
   */
  protected $parsed = [];

  /**
   * @var string
   */
  protected $environment;

  /**
   * @var string
   */
  protected $configDir;

  /**
   * @var \Illuminate\Filesystem\Filesystem
   */
  protected $files;

  public function __construct($environment, $configDir, Filesystem $files = null)
  {
    $this->environment = $environment;
    $this->configDir = $configDir;
    $this->files = $files ?: new Filesystem;
  }

  public function has($key)
  {
    $default = microtime(true);
    return $this->get($key, $default) !== $default;
  }

  public function get($key, $default = null)
  {
    list($group, $item) = $this->parseKey($key);
    $items = $this->load($group);
    return array_get($items, $item, $default);
  }

  public function parseKey($key)
  {
    if (isset($this->parsed[$key])) {
      return $this->parsed[$key];
    }
    $segments = explode('.', $key);
    $group = array_shift($segments);
    $items = (count($segments) === 0) ? null : implode('.', $segments);
    $parsed = [$group, $items];
    return $this->parsed[$key] = $parsed;
  }

  protected function load($group)
  {
    if (isset($this->items[$group])) {
      return $this->items[$group];
    }
    $items = [];
    $env = $this->environment;
    $file = "{$this->configDir}/{$group}.php";
    if ($this->files->exists($file)) {
      $items = $this->files->getRequire($file);
    }
    $file = "{$this->configDir}/{$env}/{$group}.php";
    if ($this->files->exists($file)) {
      $items = $this->mergeEnvironment($items, $file);
    }
    return $this->items[$group] = $items;
  }

  protected function mergeEnvironment(array $items, $file)
  {
    return array_replace_recursive($items, $this->files->getRequire($file));
  }

  public function offsetExists($key)
  {
    return $this->has($key);
  }

  public function offsetGet($key)
  {
    return $this->get($key);
  }

  public function offsetSet($offset, $value)
  {
    throw new \LogicException('config is read only.');
  }

  public function offsetUnset($offset)
  {
    throw new \LogicException('config is read only.');
  }
}