<?php

namespace Shikiryu\WebGobbler;

class Config
{
    protected $data = null;

    protected $cache = [];


    /**
     * Config constructor.
     * @throws \JsonException
     * @throws \Exception
     */
    public function __construct($config_file)
    {
        if (!is_readable($config_file)) {
            throw new \Exception('Config file doesn\'t exist or is unreadable.');
        }

        $this->data = json_decode(file_get_contents($config_file), true, 512, JSON_THROW_ON_ERROR);
    }

    /**
     * @param      $key
     * @param null $default
     *
     * @return mixed|null
     */
    public function get($key, $default = null)
    {
        if ($this->has($key)) {
            return $this->cache[$key];
        }

        return $default;
    }

    /**
     * @param string $key
     *
     * @return bool
     */
    public function has($key)
    {
        // Check if already cached
        if (isset($this->cache[$key])) {
            return true;
        }

        $segments = explode('.', $key);
        $root = $this->data;

        // nested case
        foreach ($segments as $segment) {
            if (array_key_exists($segment, $root)) {
                $root = $root[$segment];
                continue;
            }

            return false;
        }

        // Set cache for the given key
        $this->cache[$key] = $root;

        return true;
    }

}