<?php

namespace App\Core;

class Config
{
    private static ?self $instance = null;

    /** @var array<string, mixed> */
    private array $values = [];

    private function __construct()
    {
        $this->loadEnv();
        $this->loadConfigFiles();
    }

    public static function getInstance(): self
    {
        if (self::$instance === null) {
            self::$instance = new self();
        }

        return self::$instance;
    }

    public function get(string $key, $default = null)
    {
        $segments = explode('.', $key);
        $value = $this->values;

        foreach ($segments as $segment) {
            if (!is_array($value) || !array_key_exists($segment, $value)) {
                return $default;
            }
            $value = $value[$segment];
        }

        return $value;
    }

    /**
     * @param array<string, mixed> $config
     */
    public function set(array $config): void
    {
        $this->values = array_replace_recursive($this->values, $config);
    }

    private function loadEnv(): void
    {
        $envPath = base_path('.env');
        if (!file_exists($envPath)) {
            return;
        }

        $lines = file($envPath, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
        if ($lines === false) {
            return;
        }

        foreach ($lines as $line) {
            if (str_starts_with(trim($line), '#')) {
                continue;
            }

            [$name, $value] = array_map('trim', explode('=', $line, 2) + [1 => '']);
            $value = trim($value, "\"' ");
            $_ENV[$name] = $value;
            putenv("{$name}={$value}");
        }
    }

    private function loadConfigFiles(): void
    {
        $configDir = base_path('config');
        if (!is_dir($configDir)) {
            return;
        }

        $files = glob($configDir . '/*.php');
        if ($files === false) {
            return;
        }

        foreach ($files as $file) {
            $key = basename($file, '.php');
            /** @var array<string, mixed> $data */
            $data = require $file;
            $this->values[$key] = $data;
        }
    }
}