<?php

namespace League\Flysystem;

class Config
{
    /**
     * @var  array  $settings
     */
    protected $settings = array();

    /**
     * @var  Config  $fallback
     */
    protected $fallback;

    /**
     * Constructor
     *
     * @param  array  $settings
     */
    public function __construct(array $settings = array())
    {
        $this->settings = $settings;
    }

    /**
     * Get a setting
     *
     * @param   string  $key
     * @param   mixed   $default
     * @return  mixed   config setting or default when not found
     */
    public function get($key, $default = null)
    {
        if ( ! array_key_exists($key, $this->settings)) {
            return $this->getDefault($key, $default);
        }

        return $this->settings[$key];
    }

    /**
     * Check if an item exists by key
     *
     * @param   string  $key
     * @return  bool
     */
    public function has($key)
    {
        return array_key_exists($key, $this->settings);
    }

    /**
     * Try to retrieve a default setting from a config fallback
     *
     * @param   string  $key
     * @param   mixed   $default
     * @return  mixed   config setting or default when not found
     */
    protected function getDefault($key, $default)
    {
        if ( ! $this->fallback) {
            return $default;
        }

        return $this->fallback->get($key, $default);
    }

    /**
     * Set a setting
     *
     * @param   string  $key
     * @param   mixed   $value
     * @return  $this
     */
    public function set($key, $value)
    {
        $this->settings[$key] = $value;

        return $this;
    }

    /**
     * Set the fallback
     *
     * @param   Config  $fallback
     * @return  $this
     */
    public function setFallback(Config $fallback)
    {
        $this->fallback = $fallback;

        return $this;
    }
}
