<?php
require_once __DIR__ . '/../lib/auth.php';
require_admin();

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    header('Location: ../pages/admin.php');
    exit;
}

/* ── Login attempts ────────────────────────────────────────────────── */
if (($_POST['_login_action'] ?? '') === 'clear') {
    db()->exec('DELETE FROM login_attempts');
    header('Location: ../pages/admin.php?tab=login&cleared=1');
    exit;
}

/* ── User actions ──────────────────────────────────────────────────── */
if (!empty($_POST['_user_action'])) {
    $action  = $_POST['_user_action'];
    $user_id = (int)($_POST['user_id'] ?? 0);
    $back    = '../pages/admin.php?tab=nutzer';

    switch ($action) {

        case 'add_user': {
            $username = trim($_POST['username'] ?? '');
            $uname    = trim($_POST['name']     ?? '');
            $email    = trim($_POST['email']    ?? '');
            $telefon  = trim($_POST['telefon']  ?? '');
            $role     = in_array($_POST['role'] ?? '', ['user', 'admin'], true) ? $_POST['role'] : 'user';
            $password = $_POST['password'] ?? '';

            if ($username === '' || $uname === '' || strlen($password) < 6) {
                header('Location: ' . $back . '&user_msg=' . urlencode('Benutzername, Name und Passwort (mind. 6 Zeichen) sind Pflichtfelder.'));
                exit;
            }
            try {
                $hash = password_hash($password, PASSWORD_BCRYPT, ['cost' => 12]);
                $stmt = db()->prepare(
                    'INSERT INTO users (username, name, role, password_hash, active, created_at, email, telefon)
                     VALUES (?, ?, ?, ?, 1, ?, ?, ?)'
                );
                $stmt->execute([$username, $uname, $role, $hash, date('c'), $email, $telefon]);
            } catch (\PDOException $ex) {
                $msg = str_contains($ex->getMessage(), 'UNIQUE') ? 'Benutzername bereits vergeben.' : 'Datenbankfehler.';
                header('Location: ' . $back . '&user_msg=' . urlencode($msg));
                exit;
            }
            header('Location: ' . $back . '&user_ok=1&user_msg=' . urlencode('Nutzer erstellt.'));
            exit;
        }

        case 'edit_user': {
            $uname   = trim($_POST['name']    ?? '');
            $email   = trim($_POST['email']   ?? '');
            $telefon = trim($_POST['telefon'] ?? '');
            $role    = in_array($_POST['role'] ?? '', ['user', 'admin'], true) ? $_POST['role'] : 'user';
            $active  = (int)(bool)($_POST['active'] ?? 0);

            if ($user_id < 1 || $uname === '') {
                header('Location: ' . $back . '&user_msg=' . urlencode('Ungültige Eingabe.'));
                exit;
            }
            $stmt = db()->prepare(
                'UPDATE users SET name=?, email=?, telefon=?, role=?, active=? WHERE id=?'
            );
            $stmt->execute([$uname, $email, $telefon, $role, $active, $user_id]);
            header('Location: ' . $back . '&user_ok=1&user_msg=' . urlencode('Nutzer gespeichert.'));
            exit;
        }

        case 'change_password': {
            $password = $_POST['new_password'] ?? '';
            if ($user_id < 1 || strlen($password) < 6) {
                header('Location: ' . $back . '&user_msg=' . urlencode('Passwort muss mindestens 6 Zeichen lang sein.'));
                exit;
            }
            $hash = password_hash($password, PASSWORD_BCRYPT, ['cost' => 12]);
            $stmt = db()->prepare('UPDATE users SET password_hash=? WHERE id=?');
            $stmt->execute([$hash, $user_id]);
            header('Location: ' . $back . '&user_ok=1&user_msg=' . urlencode('Passwort geändert.'));
            exit;
        }

        case 'delete_user': {
            if ($user_id < 1) {
                header('Location: ' . $back . '&user_msg=' . urlencode('Ungültige Nutzer-ID.'));
                exit;
            }
            $stmt = db()->prepare('SELECT username FROM users WHERE id=?');
            $stmt->execute([$user_id]);
            $row = $stmt->fetch();
            if (!$row) {
                header('Location: ' . $back . '&user_msg=' . urlencode('Nutzer nicht gefunden.'));
                exit;
            }
            if ($row['username'] === current_username()) {
                header('Location: ' . $back . '&user_msg=' . urlencode('Den eigenen Account kann man nicht löschen.'));
                exit;
            }
            $stmt = db()->prepare('DELETE FROM users WHERE id=?');
            $stmt->execute([$user_id]);
            header('Location: ' . $back . '&user_ok=1&user_msg=' . urlencode('Nutzer gelöscht.'));
            exit;
        }

        default:
            header('Location: ' . $back . '&user_msg=' . urlencode('Unbekannte Aktion.'));
            exit;
    }
}

/* ── Request actions ───────────────────────────────────────────────── */
$request_id = (int)($_POST['request_id'] ?? 0);
$action     = $_POST['action'] ?? '';
$admin_note = trim($_POST['admin_note'] ?? '');
$type       = $_POST['type'] ?? '';

$allowed_types = ['urlaubsantrag', 'abwesenheitsantrag', 'benefitsantrag', 'werben', 'fortbildungsantrag', 'stundennachweis'];

if (!in_array($type, $allowed_types, true)) {
    header('Location: ../pages/admin.php?error=' . urlencode('Ungültiger Antragstyp.'));
    exit;
}

/* ── Delete request ────────────────────────────────────────────────── */
if ($action === 'delete') {
    if ($request_id < 1) {
        header('Location: ../pages/admin.php?error=' . urlencode('Ungültige Antrags-ID.'));
        exit;
    }
    $table = 'requests_' . $type;
    $stmt  = db()->prepare("SELECT * FROM $table WHERE id = ?");
    $stmt->execute([$request_id]);
    $row = $stmt->fetch();
    if (!$row) {
        header('Location: ../pages/admin.php?error=' . urlencode('Antrag nicht gefunden.'));
        exit;
    }
    // Delete associated file for types that have uploads
    if (in_array($type, ['stundennachweis', 'fortbildungsantrag'], true) && !empty($row['filename'])) {
        $file_path = __DIR__ . '/../uploads/' . $row['filename'];
        if (is_file($file_path)) {
            unlink($file_path);
        }
    }
    $stmt = db()->prepare("DELETE FROM $table WHERE id = ?");
    $stmt->execute([$request_id]);
    header('Location: ../pages/admin.php?deleted=1');
    exit;
}

/* ── Status update ─────────────────────────────────────────────────── */
if (!in_array($action, ['accepted', 'rejected'], true) || $request_id < 1) {
    header('Location: ../pages/admin.php?error=' . urlencode('Ungültige Aktion.'));
    exit;
}

$table = 'requests_' . $type;
$stmt  = db()->prepare("SELECT id FROM $table WHERE id = ?");
$stmt->execute([$request_id]);
if (!$stmt->fetch()) {
    header('Location: ../pages/admin.php?error=' . urlencode('Antrag nicht gefunden.'));
    exit;
}

$stmt = db()->prepare("UPDATE $table SET status = ?, admin_note = ?, updated_at = ? WHERE id = ?");
$stmt->execute([$action, $admin_note, date('c'), $request_id]);

header('Location: ../pages/admin.php?type=' . urlencode($type) . '&id=' . $request_id . '&updated=1');
exit;