<?php

namespace CrocWork\Zappy\Config;

class ConfigRepository
{
    protected array $items;

    public function __construct(string $configDirPath, string $cacheDirPath)
    {
        //Load from cache if it exists
        if($this->loadFromCache($cacheDirPath)) {
            return;
        }

        //Otherwise, load from config files
        $this->loadConfigurationFiles($configDirPath);
    }

    public function get(string $key, $default = null)
    {
        $keys = explode('.', $key);

        $value = $this->items;
        foreach($keys as $index) {
            if(!key_exists($index, $value)) return $default;
            $value = $value[$index];
        }

        return $value;
    }

    protected function loadFromCache(string $cacheDirPath): bool
    {
        if(!file_exists($cacheDirPath) || !file_exists($cacheDirPath . DIRECTORY_SEPARATOR . 'config-cache.php')) {
            return false;
        }

        $this->items = require $cacheDirPath . DIRECTORY_SEPARATOR . 'config-cache.php';
        return true;
    }

    protected function loadConfigurationFiles(string $configDirPath)
    {
        $files = glob($configDirPath . DIRECTORY_SEPARATOR . '*.php');

        if($files === false || empty($files)) {
            throw new \RuntimeException('Unable to load configuration, no configuration files found.');
        } elseif(!in_array($configDirPath . DIRECTORY_SEPARATOR . 'application.php', $files)) {
            throw new \RuntimeException('Unable to load the application configuration, app configuration file is missing.');
        }

        $this->items = [];
        foreach($files as $file) {
            $items = require $file;
            $key =  basename($file, '.php');
            $this->items[$key] = $items;
            //$this->items = array_merge($this->items, $items);
        }
    }

    protected function writeToCache()
    {
        // TODO: Write caching function for configuration
    }
}