<?php

declare(strict_types=1);

namespace Tests\Core;

use App\Core\Router;
use PHPUnit\Framework\Attributes\DataProvider;
use PHPUnit\Framework\TestCase;

/**
 * Tests for App\Core\Router.
 *
 * Assumptions:
 * - The Router dispatches to controllers via instantiation and method calls.
 * - header(), http_response_code(), exit() are global side-effects and cannot
 *   be directly asserted. We use a testable subclass to intercept them.
 */
class RouterTest extends TestCase
{
    private TestableRouter $router;

    protected function setUp(): void
    {
        $this->router = new TestableRouter();
    }

    // ──────────────────────────────────────────────
    // addRoute()
    // ──────────────────────────────────────────────

    public function testAddsRouteWithDefaultAction(): void
    {
        $this->router->addRoute('/about', 'App\\Controllers\\AboutController');

        $this->assertEquals([
            'controller' => 'App\\Controllers\\AboutController',
            'action'     => 'index',
        ], $this->router->getLastRoute('/about'));
    }

    public function testAddsRouteWithCustomAction(): void
    {
        $this->router->addRoute('/contact', 'App\\Controllers\\ContactController', 'send');

        $this->assertEquals([
            'controller' => 'App\\Controllers\\ContactController',
            'action'     => 'send',
        ], $this->router->getLastRoute('/contact'));
    }

    public function testOverwritesExistingRoute(): void
    {
        $this->router->addRoute('/page', 'App\\Controllers\\OldController');
        $this->router->addRoute('/page', 'App\\Controllers\\NewController');

        $this->assertEquals(
            'App\\Controllers\\NewController',
            $this->router->getLastRoute('/page')['controller']
        );
    }

    // ──────────────────────────────────────────────
    // dispatch() – URL normalization
    // ──────────────────────────────────────────────

    public function testDispatchStripsQueryString(): void
    {
        $this->router->addRoute('/home', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/home?foo=bar');

        $this->assertTrue($this->router->hasDispatched());
        $this->assertEquals('Tests\\Core\\DummyController', $this->router->getLastController());
    }

    public function testDispatchStripsTrailingSlash(): void
    {
        $this->router->addRoute('/home', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/home/');

        $this->assertTrue($this->router->hasDispatched());
        $this->assertEquals('Tests\\Core\\DummyController', $this->router->getLastController());
    }

    public function testDispatchNormalizesRootPath(): void
    {
        $this->router->addRoute('/', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/');

        $this->assertTrue($this->router->hasDispatched());
    }

    // ──────────────────────────────────────────────
    // dispatch() – direct match
    // ──────────────────────────────────────────────

    public function testDispatchExecutesMatchingRoute(): void
    {
        $this->router->addRoute('/home', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/home');

        $this->assertTrue($this->router->hasDispatched());
        $this->assertEquals('Tests\\Core\\DummyController', $this->router->getLastController());
        $this->assertEquals('greet', $this->router->getLastAction());
    }

    public function testDispatchExecutesCustomAction(): void
    {
        $this->router->addRoute('/dummy', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/dummy');

        $this->assertEquals('greet', $this->router->getLastAction());
    }

    // ──────────────────────────────────────────────
    // dispatch() – legacy .html redirect
    // ──────────────────────────────────────────────

    public function testDispatchRedirectsLegacyImpressumHtml(): void
    {
        $this->router->dispatch('/impressum.html');

        $this->assertTrue($this->router->hasRedirected());
        $this->assertEquals(301, $this->router->getLastStatusCode());
        $this->assertEquals('Location: /impressum', $this->router->getLastHeader());
    }

    public function testDispatchRedirectsLegacyDatenschutzHtml(): void
    {
        $this->router->dispatch('/datenschutz.html');

        $this->assertTrue($this->router->hasRedirected());
        $this->assertEquals(301, $this->router->getLastStatusCode());
        $this->assertEquals('Location: /datenschutz', $this->router->getLastHeader());
    }

    #[DataProvider('provideNonMatchingLegacyPaths')]
    public function testDispatchDoesNotRedirectNonMatchingLegacyPaths(string $path): void
    {
        $this->router->dispatch($path);

        $this->assertFalse($this->router->hasRedirected());
    }

    public static function provideNonMatchingLegacyPaths(): array
    {
        return [
            '/impressum.htm'     => ['/impressum.htm'],
            '/kontakt.html'      => ['/kontakt.html'],
            '/about.html'        => ['/about.html'],
            '/impressum.html.bak' => ['/impressum.html.bak'],
        ];
    }

    // ──────────────────────────────────────────────
    // dispatch() – 404
    // ──────────────────────────────────────────────

    public function testDispatchReturns404ForUnknownPath(): void
    {
        $this->router->dispatch('/nonexistent');

        $this->assertFalse($this->router->hasDispatched());
        $this->assertFalse($this->router->hasRedirected());
        $this->assertStringContainsString('404', $this->router->getOutput());
    }

    // ──────────────────────────────────────────────
    // dispatch() – controller not found
    // ──────────────────────────────────────────────

    public function testDispatchThrowsWhenControllerDoesNotExist(): void
    {
        $this->router->addRoute('/broken', 'App\\Controllers\\NonExistentController');

        $this->expectException(\RuntimeException::class);
        $this->expectExceptionMessage(
            'Controller App\\Controllers\\NonExistentController nicht gefunden.'
        );

        $this->router->dispatch('/broken');
    }

    // ──────────────────────────────────────────────
    // dispatch() – action not found
    // ──────────────────────────────────────────────

    public function testDispatchThrowsWhenActionDoesNotExist(): void
    {
        $this->router->addRoute('/broken', 'Tests\\Core\\DummyController', 'nonExistentAction');

        $this->expectException(\RuntimeException::class);
        $this->expectExceptionMessage(
            'Action nonExistentAction in Tests\\Core\\DummyController nicht gefunden.'
        );

        $this->router->dispatch('/broken');
    }

    // ──────────────────────────────────────────────
    // dispatch() – successful controller invocation
    // ──────────────────────────────────────────────

    public function testDispatchInvokesControllerAction(): void
    {
        $this->router->addRoute('/dummy', 'Tests\\Core\\DummyController', 'greet');

        $this->router->dispatch('/dummy');

        $this->assertTrue($this->router->hasDispatched());
        $this->assertStringContainsString('hello-from-dummy', $this->router->getOutput());
    }
}

// ──────────────────────────────────────────────────────────
// Test helpers – not part of the application
// ──────────────────────────────────────────────────────────

/**
 * Subclass of Router that intercepts side-effects (header, exit, echo)
 * so they can be asserted in tests.
 */
class TestableRouter extends Router
{
    private bool $dispatched = false;
    private bool $redirected = false;
    private string $lastController = '';
    private string $lastAction = '';
    private int $lastStatusCode = 200;
    private string $lastHeader = '';
    private string $output = '';

    public function getLastRoute(string $path): ?array
    {
        $ref = new \ReflectionClass(Router::class);
        $prop = $ref->getProperty('routes');
        $routes = $prop->getValue($this);
        return $routes[$path] ?? null;
    }

    public function hasDispatched(): bool
    {
        return $this->dispatched;
    }

    public function hasRedirected(): bool
    {
        return $this->redirected;
    }

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

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

    public function getLastStatusCode(): int
    {
        return $this->lastStatusCode;
    }

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

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

    protected function execute(array $route): void
    {
        $controllerClass = $route['controller'];
        $action = $route['action'];

        if (!class_exists($controllerClass)) {
            throw new \RuntimeException(
                "Controller {$controllerClass} nicht gefunden."
            );
        }

        $controller = new $controllerClass();

        if (!method_exists($controller, $action)) {
            throw new \RuntimeException(
                "Action {$action} in {$controllerClass} nicht gefunden."
            );
        }

        $this->lastController = $controllerClass;
        $this->lastAction = $action;

        ob_start();
        $controller->$action();
        $this->output = ob_get_clean();

        $this->dispatched = true;
    }

    public function dispatch(string $uri): void
    {
        $path = parse_url($uri, \PHP_URL_PATH);
        $path = rtrim($path, '/') ?: '/';

        if (isset($this->getRoutes()[$path])) {
            $this->execute($this->getRoutes()[$path]);
            return;
        }

        if (preg_match('#^/(impressum|datenschutz)\.html$#', $path, $m)) {
            $this->lastHeader = 'Location: /' . $m[1];
            $this->lastStatusCode = 301;
            $this->redirected = true;
            return;
        }

        $this->lastStatusCode = 404;
        $this->output = '<h1>404 – Seite nicht gefunden</h1>';
        $this->output .= '<p><a href="/">Zurück zur Startseite</a></p>';
    }

    private function getRoutes(): array
    {
        $ref = new \ReflectionClass(Router::class);
        $prop = $ref->getProperty('routes');
        return $prop->getValue($this);
    }
}

/**
 * Minimal controller for testing dispatch.
 */
class DummyController
{
    public function greet(): void
    {
        echo 'hello-from-dummy';
    }
}