<?php
    require '../../../session.php'; 
    require '../../../config.php';
    require '../../../dbconn.php';
    require '../../../assets/utils/db_helpers.php';
    require '../../../assets/utils/classes/PasswordManager.php';

    header('Content-Type: application/json; charset=utf-8');

    $answer = ['success' => 0, 'message' => ''];

    // ─── CSRF ─────────────────────────────────────────────────────────────────
    if ($_SERVER['REQUEST_METHOD'] === 'POST') {
        $csrf = $_SERVER['HTTP_X_CSRF_TOKEN'] ?? '';
        if (empty($csrf) || $csrf !== ($_SESSION['csrf_token'] ?? '')) {
            http_response_code(403);
            exit(json_encode(['message' => 'Invalid request.']));
        }
    }

    $data = json_decode($_POST['json'] ?? '{}', true) ?: [];

    try {

        $name     = trim($data['name']     ?? '');
        $surname  = trim($data['surname']  ?? '');
        $username = strtolower(trim($data['username'] ?? ''));
        $email    = strtolower(trim($data['email']    ?? ''));
        $password = $data['password']         ?? '';
        $confirm  = $data['confirm_password'] ?? '';

        // ── Required fields ───────────────────────────────────────
        if (!$name || !$surname || !$username || !$email || !$password || !$confirm) {
            $answer['message'] = 'All fields are required.';
            http_response_code(422);
            exit(json_encode($answer));
        }

        // ── Username format ───────────────────────────────────────
        if (!preg_match('/^[a-z0-9_]+$/', $username)) {
            $answer['message'] = 'Username may only contain lowercase letters, numbers and underscores.';
            http_response_code(422);
            exit(json_encode($answer));
        }

        // ── Email format ──────────────────────────────────────────
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $answer['message'] = 'Invalid email address.';
            http_response_code(422);
            exit(json_encode($answer));
        }

        // ── Password match ────────────────────────────────────────
        if ($password !== $confirm) {
            $answer['message'] = 'Passwords do not match.';
            http_response_code(422);
            exit(json_encode($answer));
        }

        // ── Duplicate username ────────────────────────────────────
        $sth = $pdo1->prepare('SELECT user_id FROM user WHERE username = :u LIMIT 1');
        $sth->execute([':u' => $username]);
        db_check($sth, $answer);
        if ($sth->fetchColumn()) {
            $answer['message'] = 'Username is already taken.';
            http_response_code(409);
            exit(json_encode($answer));
        }

        // ── Duplicate email ───────────────────────────────────────
        $sth = $pdo1->prepare('SELECT user_id FROM user WHERE email = :e LIMIT 1');
        $sth->execute([':e' => $email]);
        db_check($sth, $answer);
        if ($sth->fetchColumn()) {
            $answer['message'] = 'An account with that email already exists.';
            http_response_code(409);
            exit(json_encode($answer));
        }

        // ── Password strength ─────────────────────────────────────
        $pm     = new PasswordManager($pdo1, $include_url);
        $result = $pm->checkStrength($password, [$name, $surname, $username, $email]);
        if ($result['score'] < PasswordManager::MIN_SCORE) {
            $msg = $result['warning'] ?: ($result['suggestions'][0] ?? 'Please choose a stronger password.');
            $answer['message'] = 'Password is too weak. ' . $msg;
            http_response_code(422);
            exit(json_encode($answer));
        }

        // ── Insert user with status=pending ───────────────────────
        $hashed      = password_hash($password, PASSWORD_BCRYPT);
        $token       = bin2hex(random_bytes(32));

        $expires_at  = date('Y-m-d H:i:s', strtotime('+30 days'));

        $sth = $pdo1->prepare("
            INSERT INTO user
                (username, name, surname, email, password, status, profile_picture, verify_token, verify_expires_at)
            VALUES
                (:username, :name, :surname, :email, :password, 'pending', '', :token, :expires)
        ");
        $sth->execute([
            ':username' => $username,
            ':name'     => $name,
            ':surname'  => $surname,
            ':email'    => $email,
            ':password' => $hashed,
            ':token'    => $token,
            ':expires'  => $expires_at,
        ]);
        db_check($sth, $answer);

        // ── Send verification email via default SMTP ──────────────
        // Build absolute URL
        $base_url   = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? 'https' : 'http')
                    . '://' . $_SERVER['HTTP_HOST']
                    . rtrim($server_url, '/');
        $verify_url = $base_url . '/login/verify.php?token=' . $token;

        require_once $include_url . 'assets/utils/module/mailer.php';

        $mailer = new mailer(['pdo1' => $pdo1]);
        $mailer->send_email([
            'company_id'   => 0,
            'smtp'         => $SMTP,
            'to'           => $email,
            'subject'      => 'Verify your email — WMS',
            'message'      => implode("\n", [
                "Hi {$name},",
                "",
                "Thanks for registering. Please verify your email address by clicking the button below:",
                "",
                "<a href=\"{$verify_url}\" style=\"display:inline-block;padding:12px 28px;background:#E66239;color:#ffffff;text-decoration:none;border-radius:6px;font-weight:600;\">Verify Email Address</a>",
                "",
                "Or copy and paste this link into your browser:",
                "<a href=\"{$verify_url}\">{$verify_url}</a>",
                "",
                "This link will expire in 30 days.",
                "",
                "If you did not create an account, you can ignore this email.",
            ]),
            'channel_name' => 'WMS',
            'key'          => $pinkey,
        ]);

        $answer['success'] = 1;
        $answer['message'] = 'Account created! Please check your email to verify your account.';

    } catch (Exception $e) {
        error_log('[register] ' . $e->getMessage());
        $answer['message'] = 'Registration failed. Please try again.';
        http_response_code(500);
    }

    exit(json_encode($answer));
?>