<?php
session_start();
require_once('inc/config.inc.php');
require_once('inc/functions.inc.php');
require_once __DIR__ . '/inc/vacation_absence.inc.php';

$user = check_user();
if (!is_admin_user()) {
    die('Zugriff verweigert. Nur Chefs dürfen den Leitungskalender sehen.');
}

$schemaWarning = '';
try {
    vacationAbsenceEnsureSchema($pdo);
} catch (Throwable $e) {
    $schemaWarning = 'Das Abwesenheitsschema konnte nicht automatisch aktualisiert werden: ' . $e->getMessage();
}

function adminAbsenceStatusLabel(?string $status): string
{
    $status = trim((string)$status);
    if ($status === '' || $status === 'beantragt') {
        return 'Beantragt';
    }
    if ($status === 'genehmigt') {
        return 'Genehmigt';
    }
    if ($status === 'abgelehnt') {
        return 'Abgelehnt';
    }
    return ucfirst($status);
}

function adminAbsenceColor(string $reason, string $status): string
{
    $reason = vacationAbsenceNormalizeReason($reason);
    $status = trim(strtolower($status));

    $palette = [
        'urlaub' => '#2f855a',
        'krankheit_mit_atest' => '#c53030',
        'krankheit_ohne_atest' => '#9b2c2c',
        'berufsschule' => '#dd6b20',
        'weiterbildung' => '#6b46c1',
        'persoenliche_gruende' => '#4a5568',
        'sonstiges' => '#718096',
    ];

    $color = $palette[$reason] ?? '#2d3748';
    if ($status === 'beantragt') {
        return $color;
    }

    return $color;
}

function adminAbsenceEventTitle(array $row): string
{
    $employee = trim(($row['vorname'] ?? '') . ' ' . ($row['nachname'] ?? ''));
    $reasonLabel = vacationAbsenceReasonLabel($row['absence_reason'] ?? 'urlaub');
    $statusLabel = adminAbsenceStatusLabel($row['status'] ?? '');
    if ($employee === '') {
        return $reasonLabel . ' (' . $statusLabel . ')';
    }

    if ($statusLabel !== 'Genehmigt') {
        return $employee . ' · ' . $reasonLabel . ' (' . $statusLabel . ')';
    }

    return $employee . ' · ' . $reasonLabel;
}

$events = [];

$vacStmt = $pdo->prepare("
    SELECT
        v.id,
        v.user_id,
        v.start_date,
        v.end_date,
        v.days,
        v.status,
        v.comment_user,
        v.absence_reason,
        u.vorname,
        u.nachname,
        u.email
    FROM vacations v
    JOIN users u ON u.id = v.user_id
    WHERE LOWER(TRIM(COALESCE(v.status, ''))) != 'abgelehnt'
    ORDER BY v.start_date ASC, v.end_date ASC, u.nachname ASC, u.vorname ASC
");
$vacStmt->execute();
$vacations = $vacStmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($vacations as $row) {
    $endInclusive = (new DateTime($row['end_date']))->modify('+1 day')->format('Y-m-d');
    $reason = vacationAbsenceNormalizeReason($row['absence_reason'] ?? 'urlaub');
    $status = trim((string)($row['status'] ?? ''));
    $statusLabel = adminAbsenceStatusLabel($status);

    $events[] = [
        'id' => 'vac_' . $row['id'],
        'title' => adminAbsenceEventTitle($row),
        'start' => $row['start_date'],
        'end' => $endInclusive,
        'allDay' => true,
        'backgroundColor' => adminAbsenceColor($reason, $status),
        'borderColor' => adminAbsenceColor($reason, $status),
        'extendedProps' => [
            'type' => 'absence',
            'user_id' => $row['user_id'],
            'employee_name' => trim(($row['vorname'] ?? '') . ' ' . ($row['nachname'] ?? '')),
            'email' => $row['email'] ?? '',
            'status' => $status,
            'status_label' => $statusLabel,
            'reason' => $reason,
            'reason_label' => vacationAbsenceReasonLabel($reason),
            'days' => (int)($row['days'] ?? 0),
            'comment' => $row['comment_user'] ?? '',
        ],
    ];
}

$companyStmt = $pdo->prepare("
    SELECT id, start_date, end_date, description
    FROM company_holidays
    ORDER BY start_date ASC, end_date ASC
");
$companyStmt->execute();
$companyHolidays = $companyStmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($companyHolidays as $row) {
    $endInclusive = (new DateTime($row['end_date']))->modify('+1 day')->format('Y-m-d');
    $events[] = [
        'id' => 'com_' . $row['id'],
        'title' => $row['description'] ?: 'Betriebsurlaub',
        'start' => $row['start_date'],
        'end' => $endInclusive,
        'allDay' => true,
        'backgroundColor' => '#005f73',
        'borderColor' => '#005f73',
        'extendedProps' => [
            'type' => 'company',
            'description' => $row['description'] ?: 'Betriebsurlaub',
        ],
    ];
}

include 'header.php';
?>

<div class="container">
    <h2>Leitungskalender</h2>

    <?php if (!empty($schemaWarning)): ?>
    <div class="alert alert-warning"><?php echo htmlspecialchars($schemaWarning); ?></div>
    <?php endif; ?>

    <div class="alert alert-info">
        <strong>Hinweis:</strong> Dieser Kalender zeigt alle Abwesenheiten aller Personen sowie Betriebsurlaub.
    </div>

    <div id="calendar"></div>
    <br>
    <div class="d-flex flex-wrap" style="gap: 0.5rem;">
        <span class="badge badge-success">Urlaub</span>
        <span class="badge badge-danger">Krankheit mit Attest</span>
        <span class="badge badge-dark">Krankheit ohne Attest</span>
        <span class="badge badge-warning">Berufsschule</span>
        <span class="badge badge-primary">Weiterbildung</span>
        <span class="badge badge-secondary">Persönliche Gründe</span>
        <span class="badge badge-light">Sonstiges</span>
        <span class="badge badge-info">Betriebsurlaub</span>
    </div>
    <br>
    <div id="eventDetails" style="display:none;">
        <h4>Details</h4>
        <div id="detailsContent"></div>
    </div>
</div>

<link href='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.css' rel='stylesheet' />
<script src='https://cdn.jsdelivr.net/npm/fullcalendar@5.11.3/main.min.js'></script>
<script>
document.addEventListener('DOMContentLoaded', function() {
    var calendarEl = document.getElementById('calendar');
    var events = <?php echo json_encode($events, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES); ?>;

    function formatAllDayRange(start, end) {
        var startDate = new Date(start);
        var endDate = end ? new Date(end) : null;
        var startLabel = startDate.toLocaleDateString('de-DE');
        if (!endDate) {
            return startLabel;
        }

        var inclusiveEnd = new Date(endDate.getTime() - 24 * 60 * 60 * 1000);
        return startLabel + ' - ' + inclusiveEnd.toLocaleDateString('de-DE');
    }

    var calendar = new FullCalendar.Calendar(calendarEl, {
        initialView: 'dayGridMonth',
        firstDay: 1,
        height: 700,
        events: events,
        eventClick: function(info) {
            var ev = info.event;
            var props = ev.extendedProps || {};
            var html = '<strong>' + ev.title + '</strong><br>' + formatAllDayRange(ev.start, ev.end) + '<br>';

            if (props.type === 'absence') {
                html += 'Mitarbeiter: ' + (props.employee_name || '') + '<br>';
                html += 'Grund: ' + (props.reason_label || '') + '<br>';
                html += 'Status: ' + (props.status_label || '') + '<br>';
                html += 'Tage: ' + (props.days || 0) + '<br>';
                if (props.comment) {
                    html += 'Kommentar: ' + props.comment + '<br>';
                }
            } else if (props.type === 'company') {
                html += 'Beschreibung: ' + (props.description || 'Betriebsurlaub') + '<br>';
            }

            document.getElementById('detailsContent').innerHTML = html;
            document.getElementById('eventDetails').style.display = 'block';
        }
    });

    calendar.render();
});
</script>

<?php include 'footer.php'; ?>