<?php
require_once __DIR__ . '/../config.php';
require_once __DIR__ . '/../includes/functions.php';

// Check admin login
if (!isset($_SESSION['admin_logged_in']) || !$_SESSION['admin_logged_in']) {
    header('Location: login.php');
    exit;
}

$pageTitle = 'Admins verwalten';
$message = '';
$messageType = '';

function isValidAdminPasswordInput($password) {
    return is_string($password) && strlen($password) >= 8;
}

$adminAccounts = getAdminAccounts();

function isValidAdminEmailInput($email) {
    return isValidAdminEmail($email);
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    if (isset($_POST['add_admin'])) {
        $username = normalizeAdminUsername($_POST['username'] ?? '');
        $description = normalizeAdminDescription($_POST['description'] ?? '');
        $email = normalizeAdminEmail($_POST['email'] ?? '');
        $password = $_POST['password'] ?? '';
        $passwordConfirm = $_POST['password_confirm'] ?? '';

        if (!isValidAdminUsername($username)) {
            $message = 'Ungültiger Benutzername. Erlaubt: 3-50 Zeichen (Buchstaben, Zahlen, Punkt, Unterstrich, Bindestrich).';
            $messageType = 'error';
        } elseif (isset($adminAccounts[$username])) {
            $message = 'Dieser Benutzername existiert bereits.';
            $messageType = 'error';
        } elseif (!isValidAdminDescription($description)) {
            $message = 'Beschreibung ist erforderlich (max. 120 Zeichen).';
            $messageType = 'error';
        } elseif (!isValidAdminEmailInput($email)) {
            $message = 'Gültige E-Mail ist erforderlich.';
            $messageType = 'error';
        } elseif (!isValidAdminPasswordInput($password)) {
            $message = 'Passwort muss mindestens 8 Zeichen lang sein.';
            $messageType = 'error';
        } elseif ($password !== $passwordConfirm) {
            $message = 'Passwort und Bestätigung stimmen nicht überein.';
            $messageType = 'error';
        } else {
            $adminAccounts[$username] = [
                'password_hash' => password_hash($password, PASSWORD_BCRYPT),
                'description' => $description,
                'email' => $email
            ];
            saveAdminAccounts($adminAccounts);
            $message = 'Admin wurde erfolgreich angelegt.';
            $messageType = 'success';
        }
    }

    if (isset($_POST['update_description'])) {
        $targetUsername = normalizeAdminUsername($_POST['target_username'] ?? '');
        $description = normalizeAdminDescription($_POST['description'] ?? '');
        $email = normalizeAdminEmail($_POST['email'] ?? '');

        if (!isset($adminAccounts[$targetUsername])) {
            $message = 'Admin nicht gefunden.';
            $messageType = 'error';
        } elseif (!isValidAdminDescription($description)) {
            $message = 'Beschreibung ist erforderlich (max. 120 Zeichen).';
            $messageType = 'error';
        } elseif (!isValidAdminEmailInput($email)) {
            $message = 'Gültige E-Mail ist erforderlich.';
            $messageType = 'error';
        } else {
            $adminAccounts[$targetUsername]['description'] = $description;
            $adminAccounts[$targetUsername]['email'] = $email;
            saveAdminAccounts($adminAccounts);
            $message = 'Beschreibung und E-Mail wurden aktualisiert.';
            $messageType = 'success';
        }
    }

    if (isset($_POST['change_password'])) {
        $targetUsername = normalizeAdminUsername($_POST['target_username'] ?? '');
        $newPassword = $_POST['new_password'] ?? '';
        $newPasswordConfirm = $_POST['new_password_confirm'] ?? '';

        if (!isset($adminAccounts[$targetUsername])) {
            $message = 'Admin nicht gefunden.';
            $messageType = 'error';
        } elseif (!isValidAdminPasswordInput($newPassword)) {
            $message = 'Passwort muss mindestens 8 Zeichen lang sein.';
            $messageType = 'error';
        } elseif ($newPassword !== $newPasswordConfirm) {
            $message = 'Passwort und Bestätigung stimmen nicht überein.';
            $messageType = 'error';
        } else {
            $adminAccounts[$targetUsername]['password_hash'] = password_hash($newPassword, PASSWORD_BCRYPT);
            saveAdminAccounts($adminAccounts);
            $message = 'Passwort wurde aktualisiert.';
            $messageType = 'success';
        }
    }

    if (isset($_POST['delete_admin'])) {
        $targetUsername = normalizeAdminUsername($_POST['target_username'] ?? '');

        if (!isset($adminAccounts[$targetUsername])) {
            $message = 'Admin nicht gefunden.';
            $messageType = 'error';
        } else {
            unset($adminAccounts[$targetUsername]);
            saveAdminAccounts($adminAccounts);

            if (isset($_SESSION['admin_username']) && $_SESSION['admin_username'] === $targetUsername) {
                $_SESSION['admin_logged_in'] = false;
                unset($_SESSION['admin_username']);
                session_destroy();
                header('Location: login.php');
                exit;
            }

            $message = 'Admin wurde gelöscht.';
            $messageType = 'success';
        }
    }

    $adminAccounts = getAdminAccounts();
}

$currentAdmin = isset($_SESSION['admin_username']) ? normalizeAdminUsername($_SESSION['admin_username']) : '';
$changeUsername = normalizeAdminUsername($_GET['change'] ?? '');
$selectedChangeUser = null;
$editDescriptionUsername = normalizeAdminUsername($_GET['edit_description'] ?? '');
$selectedDescriptionUser = null;

if ($changeUsername !== '') {
    if (!isset($adminAccounts[$changeUsername])) {
        if ($message === '') {
            $message = 'Ausgewählter Admin wurde nicht gefunden.';
            $messageType = 'error';
        }
    } else {
        $selectedChangeUser = $changeUsername;
    }
}

if ($editDescriptionUsername !== '') {
    if (!isset($adminAccounts[$editDescriptionUsername])) {
        if ($message === '') {
            $message = 'Ausgewählter Admin wurde nicht gefunden.';
            $messageType = 'error';
        }
    } else {
        $selectedDescriptionUser = $editDescriptionUsername;
    }
}

ksort($adminAccounts);

$bodyClass = 'admin-page';
include __DIR__ . '/../includes/header.php';
?>

<div class="admin-header">
    <h2>Admins verwalten</h2>
    <div>
        <a href="index.php" class="btn btn-secondary">Zurück zum Dashboard</a>
    </div>
</div>

<?php if ($message !== ''): ?>
    <div class="alert alert-<?php echo $messageType; ?>">
        <?php echo htmlspecialchars($message); ?>
    </div>
<?php endif; ?>

<div class="panel">
    <p><strong>Eingeloggt als:</strong> <?php echo htmlspecialchars($currentAdmin !== '' ? $currentAdmin : 'Unbekannt'); ?></p>
</div>

<div class="panel">
    <h3>Neuen Admin anlegen</h3>
    <form method="POST">
        <div class="form-group">
            <label for="username">Benutzername *</label>
            <input type="text" id="username" name="username" required maxlength="50" pattern="[A-Za-z0-9][A-Za-z0-9._-]{2,49}" placeholder="z.B. max.mustermann">
        </div>
        <div class="form-group">
                <label for="description">Beschreibung *</label>
                <input type="text" id="description" name="description" required maxlength="120" placeholder="z.B. Kassierer, Shop-Team">
            </div>
            <div class="form-group">
                <label for="email">E-Mail *</label>
                <input type="email" id="email" name="email" required maxlength="190" placeholder="z.B. max.mustermann@example.org">
            </div>
            <div class="form-group">
                <label for="password">Passwort (mind. 8 Zeichen) *</label>
                <input type="password" id="password" name="password" required minlength="8">
        </div>
        <div class="form-group">
            <label for="password_confirm">Passwort bestätigen *</label>
            <input type="password" id="password_confirm" name="password_confirm" required minlength="8">
        </div>
        <button type="submit" name="add_admin" class="btn">Admin anlegen</button>
    </form>
</div>

<div class="panel">
    <h3>Admin-Liste</h3>
    <div class="table-responsive">
        <table class="responsive-table">
            <thead>
                <tr>
                    <th>Benutzername</th>
                    <th>Beschreibung</th>
                    <th>E-Mail</th>
                    <th>Aktionen</th>
                </tr>
            </thead>
            <tbody>
            <?php foreach ($adminAccounts as $username => $account): ?>
                <tr>
                    <td data-label="Benutzername">
                        <strong><?php echo htmlspecialchars($username); ?></strong>
                        <?php if ($username === $currentAdmin): ?>
                            <span class="status status-open status-self">Du</span>
                        <?php endif; ?>
                    </td>
                    <td data-label="Beschreibung">
                        <?php echo htmlspecialchars($account['description']); ?>
                    </td>
                    <td data-label="E-Mail">
                        <?php echo htmlspecialchars($account['email']); ?>
                    </td>
                    <td data-label="Aktionen">
                        <a href="admins.php?edit_description=<?php echo urlencode($username); ?>" class="btn btn-small btn-secondary">Profil ändern</a>
                        <a href="admins.php?change=<?php echo urlencode($username); ?>" class="btn btn-small btn-secondary">Passwort ändern</a>
                        <form method="POST" class="inline-form" onsubmit="return confirm('Admin wirklich löschen?');">
                            <input type="hidden" name="target_username" value="<?php echo htmlspecialchars($username); ?>">
                            <button type="submit" name="delete_admin" class="btn btn-small">Löschen</button>
                        </form>
                    </td>
                </tr>
            <?php endforeach; ?>
            </tbody>
        </table>
    </div>
</div>

<?php if ($selectedDescriptionUser !== null): ?>
    <div class="panel">
        <h3>Profil ändern: <?php echo htmlspecialchars($selectedDescriptionUser); ?></h3>
        <form method="POST">
            <input type="hidden" name="target_username" value="<?php echo htmlspecialchars($selectedDescriptionUser); ?>">
            <div class="form-group">
                <label for="description_edit">Beschreibung *</label>
                <input type="text" id="description_edit" name="description" maxlength="120" required value="<?php echo htmlspecialchars($adminAccounts[$selectedDescriptionUser]['description']); ?>">
            </div>
            <div class="form-group">
                <label for="email_edit">E-Mail *</label>
                <input type="email" id="email_edit" name="email" maxlength="190" required value="<?php echo htmlspecialchars($adminAccounts[$selectedDescriptionUser]['email']); ?>">
            </div>
            <button type="submit" name="update_description" class="btn">Profil speichern</button>
            <a href="admins.php" class="btn btn-secondary">Abbrechen</a>
        </form>
    </div>
<?php endif; ?>

<?php if ($selectedChangeUser !== null): ?>
    <div class="panel">
        <h3>Passwort ändern: <?php echo htmlspecialchars($selectedChangeUser); ?></h3>
        <form method="POST">
            <input type="hidden" name="target_username" value="<?php echo htmlspecialchars($selectedChangeUser); ?>">
            <div class="form-group">
                <label for="new_password">Neues Passwort (mind. 8 Zeichen) *</label>
                <input type="password" id="new_password" name="new_password" required minlength="8">
            </div>
            <div class="form-group">
                <label for="new_password_confirm">Neues Passwort bestätigen *</label>
                <input type="password" id="new_password_confirm" name="new_password_confirm" required minlength="8">
            </div>
            <button type="submit" name="change_password" class="btn">Passwort speichern</button>
            <a href="admins.php" class="btn btn-secondary">Abbrechen</a>
        </form>
    </div>
<?php endif; ?>

<?php include __DIR__ . '/../includes/footer.php'; ?>