<?php

declare(strict_types=1);

namespace Core;

class Router
{
    private array $routes = [];

    public function get(string $path, array|callable $handler, array $middlewares = []): void
    {
        $this->addRoute('GET', $path, $handler, $middlewares);
    }

    public function post(string $path, array|callable $handler, array $middlewares = []): void
    {
        $this->addRoute('POST', $path, $handler, $middlewares);
    }

    public function put(string $path, array|callable $handler, array $middlewares = []): void
    {
        $this->addRoute('PUT', $path, $handler, $middlewares);
    }

    public function delete(string $path, array|callable $handler, array $middlewares = []): void
    {
        $this->addRoute('DELETE', $path, $handler, $middlewares);
    }

    public function options(string $path, array|callable $handler): void
    {
        $this->addRoute('OPTIONS', $path, $handler, []);
    }

    private function addRoute(string $method, string $path, array|callable $handler, array $middlewares): void
    {
        $pattern = preg_replace('/\{([a-zA-Z0-9_]+)\}/', '(?P<$1>[^/]+)', $path);
        $pattern = '#^' . $pattern . '$#';

        $this->routes[] = [
            'method' => $method,
            'path' => $path,
            'pattern' => $pattern,
            'handler' => $handler,
            'middlewares' => $middlewares,
        ];
    }

    public function dispatch(Request $request): void
    {
        // Handle preflight CORS OPTIONS requests immediately
        if ($request->getMethod() === 'OPTIONS') {
            Response::json(['status' => 'ok']);
        }

        $method = $request->getMethod();
        $path = $request->getPath();

        foreach ($this->routes as $route) {
            if ($route['method'] !== $method) {
                continue;
            }

            if (preg_match($route['pattern'], $path, $matches)) {
                $params = [];
                foreach ($matches as $key => $value) {
                    if (is_string($key)) {
                        $params[$key] = $value;
                    }
                }

                $this->runMiddlewares($route['middlewares'], $request, function () use ($route, $request, $params) {
                    $this->executeHandler($route['handler'], $request, $params);
                });

                return;
            }
        }

        Response::notFound("Endpoint not found: [{$method}] {$path}");
    }

    private function runMiddlewares(array $middlewares, Request $request, callable $target): void
    {
        $pipeline = array_reduce(
            array_reverse($middlewares),
            function ($next, $middlewareClass) {
                return function ($req) use ($next, $middlewareClass) {
                    $instance = new $middlewareClass();
                    $instance->handle($req, $next);
                };
            },
            $target
        );

        $pipeline($request);
    }

    private function executeHandler(array|callable $handler, Request $request, array $params): void
    {
        if (is_callable($handler)) {
            call_user_func($handler, $request, $params);
            return;
        }

        [$controllerClass, $methodName] = $handler;
        if (!class_exists($controllerClass)) {
            Response::error("Controller class {$controllerClass} not found", 500);
        }

        $controller = new $controllerClass();
        if (!method_exists($controller, $methodName)) {
            Response::error("Method {$methodName} not found on controller {$controllerClass}", 500);
        }

        $controller->$methodName($request, $params);
    }
}