/**
 * Platform detection utilities
 *
 * Provides functions to detect the current platform and environment
 */

// Declare global objects for TypeScript
declare const wx: unknown;
declare const my: unknown;
declare const swan: unknown;
declare const tt: unknown;
declare const qq: unknown;
declare const window: unknown;

/**
 * Supported platform types
 */
export enum PlatformType {
  /** WeChat Mini Program */
  WECHAT = 'wechat',
  /** Alipay Mini Program */
  ALIPAY = 'alipay',
  /** Baidu Smart Program */
  BAIDU = 'baidu',
  /** ByteDance Mini Program (Douyin, Toutiao) */
  BYTEDANCE = 'bytedance',
  /** QQ Mini Program */
  QQ = 'qq',
  /** Web platform */
  WEB = 'web',
  /** Unknown platform */
  UNKNOWN = 'unknown',
}

/**
 * Type guard for objects with request method
 */
function hasRequestMethod(obj: unknown): obj is { request: unknown } {
  return typeof obj === 'object' && obj !== null && 'request' in obj;
}

/**
 * Type guard for window objects with navigator
 */
function isWindowWithNavigator(obj: unknown): obj is { navigator: unknown } {
  return typeof obj === 'object' && obj !== null && 'navigator' in obj;
}

/**
 * Detects the current platform
 *
 * @returns The detected platform type
 */
export function detectPlatform(): PlatformType {
  if (typeof wx !== 'undefined' && hasRequestMethod(wx)) {
    return PlatformType.WECHAT;
  }
  if (typeof my !== 'undefined' && hasRequestMethod(my)) {
    return PlatformType.ALIPAY;
  }
  if (typeof swan !== 'undefined' && hasRequestMethod(swan)) {
    return PlatformType.BAIDU;
  }
  if (typeof tt !== 'undefined' && hasRequestMethod(tt)) {
    return PlatformType.BYTEDANCE;
  }
  if (typeof qq !== 'undefined' && hasRequestMethod(qq)) {
    return PlatformType.QQ;
  }
  if (typeof window !== 'undefined' && isWindowWithNavigator(window)) {
    return PlatformType.WEB;
  }
  return PlatformType.UNKNOWN;
}

/**
 * Gets the platform-specific global object
 *
 * @returns The platform-specific global object or null if unknown
 */
export function getPlatformGlobal(): unknown {
  switch (detectPlatform()) {
    case PlatformType.WECHAT:
      return wx;
    case PlatformType.ALIPAY:
      return my;
    case PlatformType.BAIDU:
      return swan;
    case PlatformType.BYTEDANCE:
      return tt;
    case PlatformType.QQ:
      return qq;
    case PlatformType.WEB:
      return window;
    default:
      return null;
  }
}

/**
 * Checks if the current platform is supported
 *
 * @returns True if the platform is supported, false otherwise
 */
export function isPlatformSupported(): boolean {
  const platform = detectPlatform();
  return platform !== PlatformType.UNKNOWN && platform !== PlatformType.WEB;
}

/**
 * Gets the platform name as a human-readable string
 *
 * @returns The platform name
 */
export function getPlatformName(): string {
  switch (detectPlatform()) {
    case PlatformType.WECHAT:
      return '微信小程序';
    case PlatformType.ALIPAY:
      return '支付宝小程序';
    case PlatformType.BAIDU:
      return '百度小程序';
    case PlatformType.BYTEDANCE:
      return '字节跳动小程序';
    case PlatformType.QQ:
      return 'QQ小程序';
    case PlatformType.WEB:
      return 'Web平台';
    default:
      return '未知平台';
  }
}