<?php

class Config
{
    private $configFile;
    private $config;

    public function __construct($configFile = 'config.json')
    {
        $this->configFile = $configFile;
        $this->loadConfig();
    }

    private function loadConfig()
    {
        $defaultConfig = [
            'baseUrl' => '',
            'apiKey' => '',
            'timeout' => 30,
            'headers' => [
                'Content-Type' => 'application/json',
                'Accept' => 'application/json'
            ],
            'logging' => [
                'enabled' => true,
                'logFile' => 'logs/test_results.log',
                'logLevel' => 'INFO'
            ]
        ];

        if (file_exists($this->configFile)) {
            $fileConfig = json_decode(file_get_contents($this->configFile), true);
            $this->config = array_merge($defaultConfig, $fileConfig ?: []);
        } else {
            $this->config = $defaultConfig;
        }
    }

    public function get($key = null)
    {
        if ($key === null) {
            return $this->config;
        }

        $keys = explode('.', $key);
        $value = $this->config;

        foreach ($keys as $k) {
            if (isset($value[$k])) {
                $value = $value[$k];
            } else {
                return null;
            }
        }

        return $value;
    }

    public function set($key, $value)
    {
        $keys = explode('.', $key);
        $config = &$this->config;

        foreach ($keys as $k) {
            if (!isset($config[$k])) {
                $config[$k] = [];
            }
            $config = &$config[$k];
        }

        $config = $value;
    }

    public function save()
    {
        $json = json_encode($this->config, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
        return file_put_contents($this->configFile, $json) !== false;
    }

    public function getEnvironmentVariables()
    {
        $envVars = [];
        
        if (!empty($this->config['baseUrl'])) {
            $envVars['baseUrl'] = $this->config['baseUrl'];
        }
        
        if (!empty($this->config['apiKey'])) {
            $envVars['apiKey'] = $this->config['apiKey'];
        }
        
        return $envVars;
    }

    public function validateConfig()
    {
        $errors = [];

        if (empty($this->config['baseUrl'])) {
            $errors[] = 'Base URL is required';
        } elseif (!filter_var($this->config['baseUrl'], FILTER_VALIDATE_URL)) {
            $errors[] = 'Base URL must be a valid URL';
        }

        if (empty($this->config['apiKey'])) {
            $errors[] = 'API Key is required';
        }

        if (!is_numeric($this->config['timeout']) || $this->config['timeout'] <= 0) {
            $errors[] = 'Timeout must be a positive number';
        }

        return $errors;
    }
}