<?php

namespace MintyPHP\App\Module;

use MintyPHP\I18n;
use ReflectionProperty;

/**
 * Preloads core + module translations into I18n::$strings at boot time.
 *
 * Since I18n::$strings is private static and lives in a vendor class,
 * Reflection is used once per locale to inject the merged translation map.
 */
final class ModuleI18nLoader
{
    /**
     * @param list<ModuleManifest> $manifests Active module manifests (already sorted)
     * @param string $coreI18nDir Absolute path to the core i18n/ directory
     */
    public static function preload(array $manifests, string $coreI18nDir): void
    {
        $locales = ['de', 'en'];
        $domain = I18n::$domain ?: 'default';

        $prop = new ReflectionProperty(I18n::class, 'strings');

        foreach ($locales as $locale) {
            // Load core file
            $coreFile = $coreI18nDir . '/' . $domain . '_' . $locale . '.json';
            $merged = is_file($coreFile)
                ? (json_decode(file_get_contents($coreFile), true) ?: [])
                : [];

            // Merge each module's translations on top
            foreach ($manifests as $manifest) {
                if ($manifest->i18nPath === null) {
                    continue;
                }
                $moduleFile = $manifest->i18nPath . '/' . $domain . '_' . $locale . '.json';
                if (!is_file($moduleFile)) {
                    continue;
                }
                $moduleStrings = json_decode(file_get_contents($moduleFile), true);
                if (is_array($moduleStrings)) {
                    $merged = array_merge($merged, $moduleStrings);
                }
            }

            // Inject via Reflection into I18n::$strings
            $strings = $prop->getValue();
            $strings[$domain][$locale] = $merged;
            $prop->setValue(null, $strings);
        }
    }
}
