<?php

class CalendarController
{
    private $calendarModel;

    public function __construct()
    {
        if (!isset($_SESSION['user_id'])) {
            header('Location: /logowanie');
            exit;
        }

        $this->calendarModel = new CalendarEvent();
    }

    public function index()
    {
        $userId = $_SESSION['user_id'];

        $month = $_GET['month'] ?? date('Y-m');
        $monthDate = DateTime::createFromFormat('Y-m', $month);
        if (!$monthDate) {
            $monthDate = new DateTime('first day of this month');
            $month = $monthDate->format('Y-m');
        }

        $firstDay = (clone $monthDate)->modify('first day of this month');
        $daysInMonth = (int)$firstDay->format('t');
        $startWeekday = (int)$firstDay->format('N');

        $prevMonth = (clone $monthDate)->modify('-1 month')->format('Y-m');
        $nextMonth = (clone $monthDate)->modify('+1 month')->format('Y-m');
        $monthLabel = $monthDate->format('F Y');

        $selectedDate = $_GET['date'] ?? date('Y-m-d');

        $events = $this->calendarModel->getByMonth($userId, $month);
        $eventsByDate = [];
        foreach ($events as $event) {
            $eventsByDate[$event['event_date']][] = $event;
        }

        $eventsForSelected = $this->calendarModel->getByDate($userId, $selectedDate);

        require_once __DIR__ . '/../views/calendar/index.php';
    }

    public function create()
    {
        $event = null;
        $defaultDate = $_GET['date'] ?? date('Y-m-d');
        $returnMonth = $_GET['month'] ?? date('Y-m');

        require_once __DIR__ . '/../views/calendar/form.php';
    }

    public function edit()
    {
        $eventId = $_GET['id'] ?? null;
        if (!$eventId) {
            $_SESSION['error'] = 'Nie podano ID wydarzenia';
            header('Location: /kalendarz');
            exit;
        }

        $userId = $_SESSION['user_id'];
        $event = $this->calendarModel->getById($eventId, $userId);
        if (!$event) {
            $_SESSION['error'] = 'Wydarzenie nie zostało znalezione';
            header('Location: /kalendarz');
            exit;
        }

        $defaultDate = $event['event_date'];
        $returnMonth = $_GET['month'] ?? date('Y-m', strtotime($event['event_date']));

        require_once __DIR__ . '/../views/calendar/form.php';
    }

    public function save()
    {
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            header('Location: /kalendarz');
            exit;
        }

        $userId = $_SESSION['user_id'];
        $eventId = $_POST['event_id'] ?? null;
        $title = trim($_POST['title'] ?? '');
        $content = trim($_POST['content'] ?? '');
        $eventDate = $_POST['event_date'] ?? date('Y-m-d');
        $returnMonth = $_POST['return_month'] ?? date('Y-m');

        if ($title === '') {
            $_SESSION['error'] = 'Tytuł wydarzenia jest wymagany';
            $redirect = $eventId ? "/wydarzenie/edytuj?id=$eventId&month=$returnMonth" : "/wydarzenie/nowe?date=$eventDate&month=$returnMonth";
            header('Location: ' . $redirect);
            exit;
        }

        if ($eventId) {
            $this->calendarModel->update($eventId, $userId, $title, $content, $eventDate);
            $_SESSION['success'] = 'Wydarzenie zostało zaktualizowane';
        } else {
            $this->calendarModel->create($userId, $title, $content, $eventDate);
            $_SESSION['success'] = 'Wydarzenie zostało utworzone';
        }

        header('Location: /kalendarz?month=' . $returnMonth . '&date=' . $eventDate);
        exit;
    }

    public function delete()
    {
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            header('Location: /kalendarz');
            exit;
        }

        $eventId = $_POST['event_id'] ?? null;
        $returnMonth = $_POST['return_month'] ?? date('Y-m');
        $returnDate = $_POST['return_date'] ?? date('Y-m-d');

        if (!$eventId) {
            $_SESSION['error'] = 'Nie podano ID wydarzenia';
            header('Location: /kalendarz');
            exit;
        }

        $userId = $_SESSION['user_id'];
        $result = $this->calendarModel->delete($eventId, $userId);
        if ($result) {
            $_SESSION['success'] = 'Wydarzenie zostało usunięte';
        } else {
            $_SESSION['error'] = 'Nie udało się usunąć wydarzenia';
        }

        header('Location: /kalendarz?month=' . $returnMonth . '&date=' . $returnDate);
        exit;
    }
}