<?php
/**
 * Fociz Veilige Login met Tweestapsverificatie (2FA)
 */

require_once __DIR__ . '/../includes/auth.php';
start_secure_session();

// Als er nog geen admin is, direct naar setup
if (!has_admin_user()) {
    header('Location: /auth/setup.php');
    exit;
}

// Als al ingelogd (via actieve sessie of persistente cookie), ga direct naar planner
$currentUser = get_logged_in_user();
if ($currentUser) {
    header('Location: /planner.php');
    exit;
}

$error = null;
$step = isset($_SESSION['pending_2fa_user_id']) ? 2 : 1;

// Terug naar stap 1
if (isset($_GET['action']) && $_GET['action'] === 'restart') {
    unset($_SESSION['pending_2fa_user_id'], $_SESSION['pending_2fa_user_email']);
    header('Location: /auth/login.php');
    exit;
}

// POST Verwerking
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $db = get_db_connection();

    // STAP 1: Wachtwoord verificatie
    if ($step === 1) {
        $email = strtolower(trim($_POST['email'] ?? ''));
        $password = $_POST['password'] ?? '';

        if (empty($email) || empty($password)) {
            $error = "Vul e-mailadres en wachtwoord in.";
        } else {
            $stmt = $db->prepare("SELECT id, name, email, password_hash, two_factor_secret, two_factor_enabled FROM users WHERE email = ?");
            $stmt->execute([$email]);
            $user = $stmt->fetch();

            if ($user && password_verify($password, $user['password_hash'])) {
                // Succesvol stap 1: zet tijdelijke pending sessie voor 2FA
                $_SESSION['pending_2fa_user_id'] = $user['id'];
                $_SESSION['pending_2fa_user_email'] = $user['email'];
                $_SESSION['pending_2fa_user_name'] = $user['name'];
                $step = 2;
            } else {
                $error = "Onjuist e-mailadres of wachtwoord.";
            }
        }
    }
    // STAP 2: 2FA TOTP Code verificatie
    elseif ($step === 2) {
        $userId = $_SESSION['pending_2fa_user_id'] ?? null;
        $totpCode = trim(str_replace(' ', '', $_POST['totp_code'] ?? ''));

        if (!$userId || empty($totpCode)) {
            $error = "Vul de 6-cijferige 2FA verificatiecode in.";
        } else {
            $stmt = $db->prepare("SELECT id, name, email, role, two_factor_secret, backup_codes FROM users WHERE id = ?");
            $stmt->execute([$userId]);
            $user = $stmt->fetch();

            $isValid = false;

            // 1. Controleer TOTP code
            if (!empty($user['two_factor_secret']) && TOTP::verifyCode($user['two_factor_secret'], $totpCode)) {
                $isValid = true;
            }

            // 2. Controleer optioneel backup codes
            if (!$isValid && !empty($user['backup_codes'])) {
                $backupCodes = json_decode($user['backup_codes'], true) ?: [];
                $codeUpper = strtoupper($totpCode);
                $key = array_search($codeUpper, $backupCodes);
                if ($key !== false) {
                    $isValid = true;
                    // Verbruik de backup code
                    unset($backupCodes[$key]);
                    $stmtUpdate = $db->prepare("UPDATE users SET backup_codes = ? WHERE id = ?");
                    $stmtUpdate->execute([json_encode(array_values($backupCodes)), $userId]);
                }
            }

            if ($isValid) {
                // Volledige login succesvol
                $_SESSION['user_id'] = $user['id'];
                $_SESSION['user_name'] = $user['name'];
                $_SESSION['user_email'] = $user['email'];
                $_SESSION['user_role'] = $user['role'];
                $_SESSION['is_2fa_verified'] = true;

                // Activeer persistente remember token (30 dagen blijf ingelogd)
                issue_remember_token((int)$user['id']);

                unset($_SESSION['pending_2fa_user_id'], $_SESSION['pending_2fa_user_email'], $_SESSION['pending_2fa_user_name']);

                header('Location: /planner.php');
                exit;
            } else {
                $error = "Onjuiste 2FA code. Controleer uw authenticator app en probeer opnieuw.";
            }
        }
    }
}

$pageTitle = "Fociz — Inloggen";
?>
<!DOCTYPE html>
<html lang="nl" class="dark">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title><?= htmlspecialchars($pageTitle) ?></title>
    <script src="https://cdn.tailwindcss.com"></script>
    <script src="https://unpkg.com/lucide@latest"></script>
    <style>body { background-color: #090d16; color: #f1f5f9; }</style>
</head>
<body class="min-h-screen flex items-center justify-center p-4 bg-gradient-to-br from-[#090d16] via-[#0f172a] to-[#090d16]">

<?php require_once __DIR__ . '/../includes/env_badge.php'; ?>

<div class="w-full max-w-md bg-slate-900/90 border border-slate-800 rounded-2xl shadow-2xl backdrop-blur-xl p-8">
    <!-- Header -->
    <div class="text-center mb-8">
        <div class="inline-flex items-center justify-center w-14 h-14 rounded-2xl bg-emerald-500/10 border border-emerald-500/30 text-emerald-400 mb-3 shadow-lg shadow-emerald-500/10">
            <i data-lucide="shield-check" class="w-8 h-8"></i>
        </div>
        <h1 class="text-3xl font-extrabold tracking-tight text-white">Fociz</h1>
        <p class="text-slate-400 text-sm mt-1">
            Veilig inloggen met tweestapsverificatie (2FA)
        </p>
    </div>

    <?php if ($error): ?>
        <div class="mb-6 p-4 rounded-xl bg-red-500/10 border border-red-500/30 flex items-start space-x-3 text-red-400 text-sm">
            <i data-lucide="alert-triangle" class="w-5 h-5 flex-shrink-0 mt-0.5"></i>
            <span><?= htmlspecialchars($error) ?></span>
        </div>
    <?php endif; ?>

    <?php if ($step === 1): ?>
        <!-- STAP 1: E-mail & Wachtwoord -->
        <form method="POST" action="/auth/login.php" class="space-y-4">
            <div>
                <label class="block text-xs font-medium text-slate-300 mb-1">E-mailadres</label>
                <div class="relative">
                    <input type="email" name="email" required autofocus placeholder="uw.naam@bedrijf.nl" value="<?= htmlspecialchars($_POST['email'] ?? '') ?>" class="w-full bg-slate-800/80 border border-slate-700 rounded-xl px-4 py-2.5 text-white placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500/50 text-sm transition">
                </div>
            </div>

            <div>
                <label class="block text-xs font-medium text-slate-300 mb-1">Wachtwoord</label>
                <div class="relative">
                    <input type="password" name="password" required placeholder="••••••••" class="w-full bg-slate-800/80 border border-slate-700 rounded-xl px-4 py-2.5 text-white placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500/50 text-sm transition">
                </div>
            </div>

            <button type="submit" class="w-full mt-4 bg-emerald-500 hover:bg-emerald-600 text-slate-950 font-bold py-3 px-4 rounded-xl transition shadow-lg shadow-emerald-500/20 flex items-center justify-center space-x-2">
                <span>Verder naar 2FA</span>
                <i data-lucide="arrow-right" class="w-4 h-4"></i>
            </button>
        </form>

    <?php else: ?>

        <!-- STAP 2: 2FA TOTP Code -->
        <form method="POST" action="/auth/login.php" class="space-y-5">
            <div class="text-center">
                <div class="inline-flex items-center justify-center w-12 h-12 rounded-xl bg-emerald-500/10 text-emerald-400 mb-2">
                    <i data-lucide="key" class="w-6 h-6"></i>
                </div>
                <p className="text-sm text-slate-300 font-medium">
                    Voer uw 6-cijferige verificatiecode in
                </p>
                <p class="text-xs text-slate-400 mt-1">
                    Gekoppeld aan <strong class="text-slate-200"><?= htmlspecialchars($_SESSION['pending_2fa_user_email'] ?? '') ?></strong>
                </p>
            </div>

            <div>
                <input type="text" name="totp_code" required autofocus maxlength="9" placeholder="000 000" class="w-full text-center tracking-[0.4em] font-mono text-2xl bg-slate-800/80 border border-slate-700 rounded-xl py-3 text-white placeholder-slate-600 focus:outline-none focus:ring-2 focus:ring-emerald-500/50 transition">
                <span class="text-[11px] text-slate-500 text-center block mt-1">
                    Tip: U kunt ook een 8-cijferige herstelcode invoeren.
                </span>
            </div>

            <div class="flex space-x-3">
                <a href="/auth/login.php?action=restart" class="w-1/3 text-center bg-slate-800 hover:bg-slate-700 text-slate-300 font-medium py-2.5 px-3 rounded-xl transition text-sm flex items-center justify-center">
                    Terug
                </a>
                <button type="submit" class="w-2/3 bg-emerald-500 hover:bg-emerald-600 text-slate-950 font-bold py-2.5 px-4 rounded-xl transition shadow-lg shadow-emerald-500/20 flex items-center justify-center space-x-2">
                    <span>Inloggen</span>
                    <i data-lucide="check-circle-2" class="w-4 h-4"></i>
                </button>
            </div>
        </form>

    <?php endif; ?>

    <div class="mt-8 pt-6 border-t border-slate-800/80 text-center text-xs text-slate-500">
        Toegang tot Fociz is strikt op uitnodiging. Vraag uw beheerder om een uitnodigingslink.
    </div>
</div>

<script>
    if (typeof lucide !== 'undefined') lucide.createIcons();
</script>
</body>
</html>