<?php
declare(strict_types=1);

final class Lang
{
    /** @var array<string,string> */
    private array $map;
    private string $code;

    /**
     * @param array<string,string> $map
     */
    private function __construct(string $code, array $map)
    {
        $this->code = $code;
        $this->map = $map;
    }

    public static function load(string $preferred, Settings $settings): self
    {
        $candidates = [strtolower(trim($preferred)), $settings->defaultLanguage(), 'en'];
        foreach ($candidates as $code) {
            if (!preg_match('/^[a-z]{2}$/', $code)) {
                continue;
            }
            $path = PLUGIN_ROOT . '/lang/' . $code . '.php';
            if (is_file($path)) {
                $data = require $path;
                return new self($code, is_array($data) ? $data : []);
            }
        }
        return new self('en', []);
    }

    public function code(): string
    {
        return $this->code;
    }

    /**
     * @param array<string,string|int|float> $vars
     */
    public function t(string $key, array $vars = []): string
    {
        $text = $this->map[$key] ?? $key;
        foreach ($vars as $var => $value) {
            $text = str_replace('{' . $var . '}', (string)$value, $text);
        }
        return $text;
    }

    public function translateHtml(string $html): string
    {
        if ($html === '' || empty($this->map)) {
            return $html;
        }
        $keys = array_keys($this->map);
        usort($keys, static fn (string $a, string $b): int => strlen($b) <=> strlen($a));
        return str_replace($keys, array_map(fn (string $k): string => $this->map[$k], $keys), $html);
    }
}