<?php

declare(strict_types=1);

namespace Tests\Core;

use App\Core\I18n;
use App\Core\Locale;
use PHPUnit\Framework\TestCase;

class I18nTest extends TestCase
{
    /** @var string */
    private string $tmpDir;

    protected function setUp(): void
    {
        $this->tmpDir = sys_get_temp_dir() . '/i18n-test-' . bin2hex(random_bytes(4));
        mkdir($this->tmpDir);
        I18n::setLocalesPath($this->tmpDir);
        I18n::flushCache();
    }

    protected function tearDown(): void
    {
        I18n::flushCache();
        I18n::setLocalesPath(dirname(__DIR__, 2) . '/app/Locales');
        if (is_dir($this->tmpDir)) {
            foreach (glob($this->tmpDir . '/*') as $f) {
                @unlink($f);
            }
            @rmdir($this->tmpDir);
        }
    }

    private function writeLocale(string $code, array $data): void
    {
        $content = '<?php return ' . var_export($data, true) . ';';
        file_put_contents($this->tmpDir . '/' . $code . '.php', $content);
    }

    // ──────────────────────────────────────────────
    // t(): basic lookup
    // ──────────────────────────────────────────────

    public function testReturnsKeyWhenNoLocalesExist(): void
    {
        $this->assertSame('missing.key', I18n::t('missing.key'));
    }

    public function testReturnsKeyWhenLocaleFileMissing(): void
    {
        // Only DE file exists
        $this->writeLocale('de', ['hello' => 'Hallo']);
        $this->assertSame('missing.key', I18n::t('missing.key', [], 'en'));
    }

    public function testReturnsKeyWhenKeyMissingInAllLocales(): void
    {
        $this->writeLocale('de', ['hello' => 'Hallo']);
        $this->writeLocale('en', ['other' => 'Other']);
        $this->assertSame('greeting', I18n::t('greeting', [], 'en'));
    }

    public function testFallsBackToDeWhenKeyMissingInCurrentLocale(): void
    {
        $this->writeLocale('de', ['nav.home' => 'Start']);
        $this->writeLocale('en', ['other.key' => 'Other']);
        $this->assertSame('Start', I18n::t('nav.home', [], 'en'));
    }

    public function testReturnsValueInCurrentLocale(): void
    {
        $this->writeLocale('de', ['greeting' => 'Hallo']);
        $this->writeLocale('en', ['greeting' => 'Hello']);
        $this->assertSame('Hallo', I18n::t('greeting', [], 'de'));
        $this->assertSame('Hello', I18n::t('greeting', [], 'en'));
    }

    // ──────────────────────────────────────────────
    // t(): placeholders
    // ──────────────────────────────────────────────

    public function testInterpolatesPlaceholders(): void
    {
        $this->writeLocale('de', ['welcome' => 'Willkommen, {name}!']);
        $this->assertSame(
            'Willkommen, Martin!',
            I18n::t('welcome', ['name' => 'Martin'], 'de')
        );
    }

    public function testInterpolatesMultiplePlaceholders(): void
    {
        $this->writeLocale('de', ['mail' => '{greeting}, deine Bestellung #{order} ist da.']);
        $this->assertSame(
            'Hi, deine Bestellung #42 ist da.',
            I18n::t('mail', ['greeting' => 'Hi', 'order' => '42'], 'de')
        );
    }

    public function testLeavesUnreplacedPlaceholdersAlone(): void
    {
        $this->writeLocale('de', ['x' => 'Hallo {name}']);
        $this->assertSame('Hallo {name}', I18n::t('x', [], 'de'));
    }

    // ──────────────────────────────────────────────
    // t(): default locale behavior
    // ──────────────────────────────────────────────

    public function testDefaultsToDeLocaleWhenNoneSpecified(): void
    {
        $this->writeLocale('de', ['greeting' => 'Hallo']);
        $this->assertSame('Hallo', I18n::t('greeting'));
    }

    public function testRejectsUnsupportedLocaleAndReturnsKey(): void
    {
        $this->writeLocale('de', ['greeting' => 'Hallo']);
        $this->assertSame('greeting', I18n::t('greeting', [], 'fr'));
    }

    // ──────────────────────────────────────────────
    // tn(): plural variants (MVP: {n} interpolation)
    // ──────────────────────────────────────────────

    public function testTnPicksSingularForOne(): void
    {
        $this->writeLocale('de', [
            'room.singular' => '1 Zimmer',
            'room.plural'   => '{n} Zimmer',
        ]);
        $this->assertSame('1 Zimmer', I18n::tn('room.singular', 'room.plural', 1, [], 'de'));
    }

    public function testTnPicksPluralForOtherNumbers(): void
    {
        $this->writeLocale('de', [
            'room.singular' => '1 Zimmer',
            'room.plural'   => '{n} Zimmer',
        ]);
        $this->assertSame('6 Zimmer', I18n::tn('room.singular', 'room.plural', 6, [], 'de'));
        $this->assertSame('0 Zimmer', I18n::tn('room.singular', 'room.plural', 0, [], 'de'));
    }

    // ──────────────────────────────────────────────
    // has()
    // ──────────────────────────────────────────────

    public function testHasReturnsTrueForExistingKey(): void
    {
        $this->writeLocale('de', ['greeting' => 'Hallo']);
        $this->writeLocale('en', ['greeting' => 'Hello']);
        $this->assertTrue(I18n::has('greeting', 'en'));
        $this->assertTrue(I18n::has('greeting', 'de'));
    }

    public function testHasReturnsTrueForFallbackKey(): void
    {
        $this->writeLocale('de', ['only_de' => 'Nur DE']);
        $this->assertTrue(I18n::has('only_de', 'en'));
    }

    public function testHasReturnsFalseForMissingKey(): void
    {
        $this->writeLocale('de', ['x' => 'X']);
        $this->assertFalse(I18n::has('nope', 'de'));
    }

    // ──────────────────────────────────────────────
    // Caching
    // ──────────────────────────────────────────────

    public function testCacheSurvivesAcrossCalls(): void
    {
        $this->writeLocale('de', ['k' => 'v1']);
        $this->assertSame('v1', I18n::t('k', [], 'de'));

        // Mutate the file — cached value should still be returned
        $this->writeLocale('de', ['k' => 'v2']);
        $this->assertSame('v1', I18n::t('k', [], 'de'));

        // Flush — now we see the new value
        I18n::flushCache();
        $this->assertSame('v2', I18n::t('k', [], 'de'));
    }

    public function testFlushCacheClearsAllLocales(): void
    {
        $this->writeLocale('de', ['k' => 'de-v']);
        $this->writeLocale('en', ['k' => 'en-v']);
        I18n::t('k', [], 'en');
        I18n::flushCache();
        $this->writeLocale('en', ['k' => 'en-v2']);
        $this->assertSame('en-v2', I18n::t('k', [], 'en'));
    }
}