<?php

declare(strict_types=1);

namespace Tests\Core;

use App\Core\I18n;
use PHPUnit\Framework\Attributes\DataProvider;
use PHPUnit\Framework\Attributes\Test;
use PHPUnit\Framework\TestCase;

/**
 * Guards against the most common i18n regression: a developer adds a key
 * to one Locale file and forgets the other three. CI must fail loudly.
 */
final class LocaleConsistencyTest extends TestCase
{
    /** @return array<string, array{string}> */
    public static function localeProvider(): array
    {
        return [
            'de' => ['de'],
            'en' => ['en'],
            'uk' => ['uk'],
            'ru' => ['ru'],
        ];
    }

    #[Test]
    public function allFourLocaleFilesLoadAndAreArrays(): void
    {
        foreach (self::localeProvider() as [$locale]) {
            I18n::flushCache();
            $data = require __DIR__ . '/../../app/Locales/' . $locale . '.php';
            self::assertIsArray($data, "Locale file {$locale}.php must return an array");
            self::assertNotEmpty($data, "Locale file {$locale}.php must not be empty");
        }
    }

    #[Test]
    public function everyLocaleHasExactlyTheSameKeySet(): void
    {
        $keysByLocale = [];
        foreach (self::localeProvider() as [$locale]) {
            $keysByLocale[$locale] = array_keys(require __DIR__ . '/../../app/Locales/' . $locale . '.php');
            sort($keysByLocale[$locale]);
        }

        $reference = $keysByLocale['de'];
        foreach (['en', 'uk', 'ru'] as $locale) {
            $missing = array_diff($reference, $keysByLocale[$locale]);
            $extra   = array_diff($keysByLocale[$locale], $reference);
            self::assertSame(
                [],
                $missing,
                "Locale '{$locale}' is missing keys: " . implode(', ', $missing)
            );
            self::assertSame(
                [],
                $extra,
                "Locale '{$locale}' has extra keys not in DE: " . implode(', ', $extra)
            );
        }
    }

    #[Test]
    public function noTranslationValueIsEmpty(): void
    {
        foreach (self::localeProvider() as [$locale]) {
            $data = require __DIR__ . '/../../app/Locales/' . $locale . '.php';
            foreach ($data as $key => $value) {
                self::assertIsString($value, "{$locale}.{$key} must be a string");
                self::assertNotSame('', trim($value), "{$locale}.{$key} must not be empty");
            }
        }
    }

    #[Test]
    #[DataProvider('localeProvider')]
    public function everyTranslationIsValidUtf8(string $locale): void
    {
        $data = require __DIR__ . '/../../app/Locales/' . $locale . '.php';
        foreach ($data as $key => $value) {
            self::assertTrue(
                mb_check_encoding($value, 'UTF-8'),
                "{$locale}.{$key} contains invalid UTF-8"
            );
        }
    }
}