import { ValidationResult } from './types';
import { parseQueryString } from '../helpers';

export function validateVlessUrl(url: string): ValidationResult {
  try {
    if (!url.startsWith('vless://'))
      return {
        valid: false,
        message: 'Invalid VLESS URL: must start with vless://',
      };

    if (/\s/.test(url))
      return {
        valid: false,
        message: 'Invalid VLESS URL: must not contain spaces',
      };

    const body = url.slice('vless://'.length);

    const [mainPart] = body.split('#');

    const [userHostPort, queryString] = mainPart.split('?');

    if (!userHostPort)
      return {
        valid: false,
        message: 'Invalid VLESS URL: missing host and UUID',
      };

    const [userPart, hostPortPart] = userHostPort.split('@');

    if (!userPart)
      return { valid: false, message: 'Invalid VLESS URL: missing UUID' };

    if (!hostPortPart)
      return { valid: false, message: 'Invalid VLESS URL: missing server' };

    const [host, port] = hostPortPart.split(':');

    if (!host)
      return { valid: false, message: 'Invalid VLESS URL: missing hostname' };

    if (!port)
      return { valid: false, message: 'Invalid VLESS URL: missing port' };

    const portNum = Number(port);
    if (!Number.isInteger(portNum) || portNum < 1 || portNum > 65535)
      return {
        valid: false,
        message: 'Invalid VLESS URL: invalid port number',
      };

    if (!queryString)
      return {
        valid: false,
        message: 'Invalid VLESS URL: missing query parameters',
      };

    const params = parseQueryString(queryString);

    const validTypes = [
      'tcp',
      'raw',
      'udp',
      'grpc',
      'http',
      'httpupgrade',
      'xhttp',
      'ws',
      'kcp',
    ];
    const validSecurities = ['tls', 'reality', 'none'];

    if (!params.type || !validTypes.includes(params.type))
      return {
        valid: false,
        message: 'Invalid VLESS URL: unsupported or missing type',
      };

    if (!params.security || !validSecurities.includes(params.security))
      return {
        valid: false,
        message: 'Invalid VLESS URL: unsupported or missing security',
      };

    if (params.security === 'reality') {
      if (!params.pbk)
        return {
          valid: false,
          message: 'Invalid VLESS URL: missing pbk for reality',
        };
      if (!params.fp)
        return {
          valid: false,
          message: 'Invalid VLESS URL: missing fp for reality',
        };
    }

    return { valid: true, message: _('Valid') };
  } catch (_e) {
    return { valid: false, message: _('Invalid VLESS URL: parsing failed') };
  }
}