<?php

namespace App\Tests;

use App\Ops\Download;
use App\Ops\HttpsRedirect;
use App\Ops\OriginCheck;
use PHPUnit\Framework\TestCase;

/**
 * HTTPS erzwingen aus der Verwaltung (ADR 120): eingeschaltet wird nur, wenn HTTPS vorher und
 * nachher hier ankommt, und eine Schleife wird zurückgenommen, bevor sie jemanden aussperrt.
 */
final class HttpsRedirectTest extends TestCase
{
    private string $root;
    private string $shipped;
    /** @var list<?string> */
    private array $answers = [];
    /** @var array{status: int, location: string, error: string} */
    private array $http = ['status' => 301, 'location' => 'https://www.example.de/kantsites-origin', 'error' => ''];

    protected function setUp(): void
    {
        $this->root = sys_get_temp_dir().'/kant-https-'.bin2hex(random_bytes(4));
        mkdir($this->root.'/public', 0o777, true);
        $this->shipped = (string) file_get_contents(dirname(__DIR__).'/public/.htaccess');
        file_put_contents($this->root.'/public/.htaccess', $this->shipped);
    }

    protected function tearDown(): void
    {
        @unlink($this->root.'/public/.htaccess');
        @rmdir($this->root.'/public');
        @rmdir($this->root);
    }

    public function testTheShippedFileHasTheRedirectBeforeTheFrontController(): void
    {
        // Hinter "RewriteRule ^index\.php$ - [L]" kam die Umleitung für Seiten nie an die Reihe:
        // Nach dem Umschreiben auf index.php beginnt die Runde neu und endet an dieser Regel.
        $redirect = strpos($this->shipped, '#'.HttpsRedirect::REDIRECT_LINES[0]);
        $front = strpos($this->shipped, 'RewriteRule ^index\.php$ - [L]');
        self::assertNotFalse($redirect);
        self::assertNotFalse($front);
        self::assertLessThan($front, $redirect);
        self::assertSame(['redirect' => false, 'hsts' => false, 'found' => true, 'writable' => true], $this->redirect()->state());
    }

    public function testEnablingProbesBeforeAndAfterAndSwitchesOnlyTheThreeLines(): void
    {
        $this->answers = ['ok', 'ok'];
        $result = $this->redirect()->enableRedirect('https://www.example.de/');
        self::assertTrue($result['ok'], $result['message']);
        self::assertStringContainsString('leitet mit 301', $result['message']);
        $now = (string) file_get_contents($this->root.'/public/.htaccess');
        foreach (HttpsRedirect::REDIRECT_LINES as $line) {
            self::assertMatchesRegularExpression('/^'.preg_quote($line, '/').'$/m', $now);
        }
        self::assertStringContainsString('#'.HttpsRedirect::HSTS_LINE, $now, 'HSTS bleibt ein eigener Schritt.');
        self::assertSame([], $this->answers, 'Vorher und nachher geprüft.');

        $off = $this->redirect()->disableRedirect();
        self::assertTrue($off['ok']);
        self::assertSame($this->shipped, (string) file_get_contents($this->root.'/public/.htaccess'), 'Aus heißt: wieder wie ausgeliefert.');
    }

    public function testNothingChangesWithoutWorkingHttps(): void
    {
        $this->answers = [null];
        $result = $this->redirect()->enableRedirect('https://www.example.de');
        self::assertFalse($result['ok']);
        self::assertStringContainsString('bleibt die Umleitung aus', $result['message']);
        self::assertSame($this->shipped, (string) file_get_contents($this->root.'/public/.htaccess'));

        $result = $this->redirect()->enableRedirect('http://www.example.de');
        self::assertFalse($result['ok']);
        self::assertStringContainsString('https://', $result['message']);
    }

    public function testALoopIsTakenBackAtOnce(): void
    {
        // Der Server meldet HTTPS nicht an die .htaccess: mit den Zeilen leitet auch https://
        // auf sich selbst um, die Probe danach kommt nicht mehr an.
        $this->answers = ['ok', null];
        $result = $this->redirect()->enableRedirect('https://www.example.de');
        self::assertFalse($result['ok']);
        self::assertStringContainsString('zurückgesetzt', $result['message']);
        self::assertSame($this->shipped, (string) file_get_contents($this->root.'/public/.htaccess'));
    }

    public function testAServerThatIgnoresTheRuleIsNamed(): void
    {
        $this->answers = ['ok', 'ok'];
        $this->http = ['status' => 200, 'location' => '', 'error' => ''];
        $result = $this->redirect()->enableRedirect('https://www.example.de');
        self::assertTrue($result['ok']);
        self::assertStringContainsString('antwortet mit 200', $result['message']);
    }

    public function testHstsOnlyAfterTheRedirect(): void
    {
        $this->answers = ['ok'];
        $result = $this->redirect()->switchHsts(true, 'https://www.example.de');
        self::assertFalse($result['ok']);
        self::assertStringContainsString('erst, wenn die Umleitung', $result['message']);

        $this->answers = ['ok', 'ok', 'ok'];
        $this->redirect()->enableRedirect('https://www.example.de');
        self::assertTrue($this->redirect()->switchHsts(true, 'https://www.example.de')['ok']);
        self::assertSame(['redirect' => true, 'hsts' => true, 'found' => true, 'writable' => true], $this->redirect()->state());

        // Die Umleitung aus nimmt HSTS mit.
        $this->redirect()->disableRedirect();
        self::assertSame($this->shipped, (string) file_get_contents($this->root.'/public/.htaccess'));
    }

    public function testAnUpdateKeepsWhatWasSwitchedOn(): void
    {
        $this->answers = ['ok', 'ok', 'ok'];
        $this->redirect()->enableRedirect('https://www.example.de');
        $this->redirect()->switchHsts(true, 'https://www.example.de');
        $merged = HttpsRedirect::keepEnabled($this->shipped, (string) file_get_contents($this->root.'/public/.htaccess'));
        self::assertTrue(HttpsRedirect::active($merged, HttpsRedirect::REDIRECT_LINES));
        self::assertTrue(HttpsRedirect::active($merged, [HttpsRedirect::HSTS_LINE]));
        self::assertSame($this->shipped, HttpsRedirect::keepEnabled($this->shipped, $this->shipped));
    }

    public function testTheGitUpdaterDoesNotCallTheSwitchedFileALocalChange(): void
    {
        $dirty = new \ReflectionMethod(\App\Ops\Updater::class, 'dirty');
        self::assertSame([], $dirty->invoke(null, " M public/.htaccess\n"));
        self::assertSame([], $dirty->invoke(null, 'M public/.htaccess'), 'Auch wenn die Ausgabe vorn gekürzt ist.');
        self::assertSame([' M src/Kernel.php'], $dirty->invoke(null, " M public/.htaccess\n M src/Kernel.php\n"));
        self::assertSame(['?? public/.htaccess.bak'], $dirty->invoke(null, '?? public/.htaccess.bak'));
    }

    private function redirect(): HttpsRedirect
    {
        $test = $this;
        $download = new class($test) extends Download {
            public function __construct(private HttpsRedirectTest $test)
            {
                parent::__construct();
            }

            public function get(string $url): ?string
            {
                return $this->test->nextAnswer();
            }
        };
        $check = new OriginCheck('geheim', $download);
        $this->token = $check->token();

        return new HttpsRedirect($this->root, $check, fn (string $url): array => $this->http);
    }

    private string $token = '';

    public function nextAnswer(): ?string
    {
        self::assertNotSame([], $this->answers, 'Mehr Proben als erwartet.');
        $answer = array_shift($this->answers);

        return null === $answer ? null : $this->token;
    }
}