<?php

namespace App\Core;

class Request
{
    private array $get;
    private array $post;
    private array $files;
    private array $server;
    private array $headers;

    public function __construct()
    {
        $this->get = $_GET;
        $this->post = $_POST;
        $this->files = $_FILES;
        $this->server = $_SERVER;
        $this->headers = $this->getRequestHeaders();
    }

    public function getMethod(): string
    {
        return strtoupper($this->server['REQUEST_METHOD'] ?? 'GET');
    }

    public function getPath(): string
    {
        $path = $this->server['REQUEST_URI'] ?? '/';
        $position = strpos($path, '?');
        
        if ($position !== false) {
            $path = substr($path, 0, $position);
        }
        
        return $path;
    }

    public function get(string $key, $default = null)
    {
        return $this->get[$key] ?? $default;
    }

    public function post(string $key, $default = null)
    {
        return $this->post[$key] ?? $default;
    }

    public function file(string $key)
    {
        return $this->files[$key] ?? null;
    }

    public function all(): array
    {
        return array_merge($this->get, $this->post);
    }

    public function only(array $keys): array
    {
        $data = $this->all();
        return array_intersect_key($data, array_flip($keys));
    }

    public function except(array $keys): array
    {
        $data = $this->all();
        return array_diff_key($data, array_flip($keys));
    }

    public function has(string $key): bool
    {
        return isset($this->get[$key]) || isset($this->post[$key]);
    }

    public function isPost(): bool
    {
        return $this->getMethod() === 'POST';
    }

    public function isGet(): bool
    {
        return $this->getMethod() === 'GET';
    }

    public function isAjax(): bool
    {
        return isset($this->headers['X-Requested-With']) && 
               $this->headers['X-Requested-With'] === 'XMLHttpRequest';
    }

    public function getHeader(string $name): ?string
    {
        return $this->headers[$name] ?? null;
    }

    public function getHeaders(): array
    {
        return $this->headers;
    }

    public function getIp(): string
    {
        return $this->server['REMOTE_ADDR'] ?? '0.0.0.0';
    }

    public function getUserAgent(): string
    {
        return $this->server['HTTP_USER_AGENT'] ?? '';
    }

    public function getContentType(): string
    {
        return $this->server['CONTENT_TYPE'] ?? '';
    }

    public function getContentLength(): int
    {
        return (int) ($this->server['CONTENT_LENGTH'] ?? 0);
    }

    public function validate(array $rules): array
    {
        $errors = [];
        $data = $this->all();

        foreach ($rules as $field => $rule) {
            $value = $data[$field] ?? null;
            
            if (strpos($rule, 'required') !== false && empty($value)) {
                $errors[$field][] = 'Das Feld ist erforderlich.';
                continue;
            }

            if (!empty($value)) {
                if (strpos($rule, 'email') !== false && !filter_var($value, FILTER_VALIDATE_EMAIL)) {
                    $errors[$field][] = 'Ungültige E-Mail-Adresse.';
                }

                if (strpos($rule, 'min:') !== false) {
                    preg_match('/min:(\d+)/', $rule, $matches);
                    $min = (int) $matches[1];
                    if (strlen($value) < $min) {
                        $errors[$field][] = "Mindestens {$min} Zeichen erforderlich.";
                    }
                }

                if (strpos($rule, 'max:') !== false) {
                    preg_match('/max:(\d+)/', $rule, $matches);
                    $max = (int) $matches[1];
                    if (strlen($value) > $max) {
                        $errors[$field][] = "Maximal {$max} Zeichen erlaubt.";
                    }
                }

                if (strpos($rule, 'numeric') !== false && !is_numeric($value)) {
                    $errors[$field][] = 'Nur Zahlen erlaubt.';
                }

                if (strpos($rule, 'date') !== false && !strtotime($value)) {
                    $errors[$field][] = 'Ungültiges Datum.';
                }
            }
        }

        return $errors;
    }

    private function getRequestHeaders(): array
    {
        $headers = [];
        
        foreach ($this->server as $key => $value) {
            if (strpos($key, 'HTTP_') === 0) {
                $header = str_replace('_', '-', strtolower(substr($key, 5)));
                $headers[$header] = $value;
            }
        }
        
        return $headers;
    }
}