const DEFAULT_ACK_TEXT = '已收到，正在处理，完成后发到这里。';
const DEFAULT_PROGRESS_TEXT = '还在处理，请稍等片刻。';
const DEFAULT_STATUS_TEXT =
  '我在这边。上一条如果还没完成，我会继续把结果发给你；你也可以直接补一句要求。';
const DEFAULT_UNSUPPORTED_TEXT = '当前先支持文字消息，你可以直接发文字给我。';
const DEFAULT_UNBOUND_TEXT = '先点这里完成绑定，再继续和专属 Agent 对话：';
const DEFAULT_PROGRESS_DELAY_MS = 8000;
const DEFAULT_SESSION_IDLE_ROTATE_MS = 30 * 60 * 1000;
const DEFAULT_SESSION_MESSAGE_ROTATE_COUNT = 200;
const DEFAULT_WECHAT_TOKEN_URL = 'https://api.weixin.qq.com/cgi-bin/stable_token';
const DEFAULT_WECHAT_CUSTOMER_SERVICE_URL =
  'https://api.weixin.qq.com/cgi-bin/message/custom/send';
const DEFAULT_WECHAT_JSAPI_TICKET_URL = 'https://api.weixin.qq.com/cgi-bin/ticket/getticket';

function deriveWechatEndpointFromUrl(baseUrl, suffix) {
  const normalized = String(baseUrl ?? '').trim();
  if (!normalized) return '';
  try {
    const url = new URL(normalized);
    return `${url.origin}${suffix}`;
  } catch {
    return '';
  }
}

function parseCsvList(value = '') {
  return String(value ?? '')
    .split(',')
    .map((item) => item.trim())
    .filter(Boolean);
}

export function loadWechatMpConfig(env = process.env) {
  const appId = env.H5_WECHAT_MP_APP_ID?.trim() ?? env.H5_WECHAT_APP_ID?.trim() ?? '';
  const appSecret =
    env.H5_WECHAT_MP_APP_SECRET?.trim() ?? env.H5_WECHAT_APP_SECRET?.trim() ?? '';
  const token = env.H5_WECHAT_MP_TOKEN?.trim() ?? '';
  const publicBaseUrl = env.H5_PUBLIC_BASE_URL?.trim()?.replace(/\/$/, '') ?? '';
  const generatedImagePublicBaseUrls = [...new Set([
    publicBaseUrl,
    env.IMGPROXY_BASE_URL?.trim()?.replace(/\/$/, '') ?? '',
    ...parseCsvList(env.H5_WECHAT_MP_GENERATED_IMAGE_BASE_URLS).map((value) => value.replace(/\/$/, '')),
  ].filter(Boolean))];
  const enabledFlag = env.H5_WECHAT_MP_ENABLED === '1';
  const bindPath = env.H5_WECHAT_MP_BIND_PATH?.trim() || '/auth/wechat/authorize?intent=login';
  return {
    enabled: enabledFlag && Boolean(appId && appSecret && token && publicBaseUrl),
    appId,
    appSecret,
    token,
    publicBaseUrl,
    bindPath,
    ackText: env.H5_WECHAT_MP_ACK_TEXT?.trim() || DEFAULT_ACK_TEXT,
    ackRandomEnabled: env.H5_WECHAT_MP_ACK_RANDOM !== '0',
    ackNicknameEnabled: env.H5_WECHAT_MP_ACK_NICKNAME !== '0',
    progressText: env.H5_WECHAT_MP_PROGRESS_TEXT?.trim() || DEFAULT_PROGRESS_TEXT,
    progressDelayMs: Math.max(
      0,
      Number(env.H5_WECHAT_MP_PROGRESS_DELAY_MS ?? DEFAULT_PROGRESS_DELAY_MS),
    ),
    sessionIdleRotateMs: Math.max(
      0,
      Number(env.H5_WECHAT_MP_SESSION_IDLE_ROTATE_MS ?? DEFAULT_SESSION_IDLE_ROTATE_MS),
    ),
    sessionMessageRotateCount: Math.max(
      0,
      Number(env.H5_WECHAT_MP_SESSION_MESSAGE_ROTATE_COUNT ?? DEFAULT_SESSION_MESSAGE_ROTATE_COUNT),
    ),
    statusText: env.H5_WECHAT_MP_STATUS_TEXT?.trim() || DEFAULT_STATUS_TEXT,
    unsupportedText: env.H5_WECHAT_MP_UNSUPPORTED_TEXT?.trim() || DEFAULT_UNSUPPORTED_TEXT,
    unboundTextPrefix: env.H5_WECHAT_MP_UNBOUND_TEXT_PREFIX?.trim() || DEFAULT_UNBOUND_TEXT,
    tokenUrl: env.H5_WECHAT_MP_TOKEN_URL?.trim() || DEFAULT_WECHAT_TOKEN_URL,
    customerServiceUrl:
      env.H5_WECHAT_MP_CUSTOMER_SERVICE_URL?.trim() || DEFAULT_WECHAT_CUSTOMER_SERVICE_URL,
    jsapiTicketUrl:
      env.H5_WECHAT_MP_JSAPI_TICKET_URL?.trim() ||
      deriveWechatEndpointFromUrl(env.H5_WECHAT_MP_TOKEN_URL?.trim(), '/cgi-bin/ticket/getticket') ||
      DEFAULT_WECHAT_JSAPI_TICKET_URL,
    mediaPublicBaseUrl:
      env.H5_WECHAT_MP_MEDIA_PUBLIC_BASE_URL?.trim()?.replace(/\/$/, '') || publicBaseUrl,
    generatedImagePublicBaseUrls,
    maxImageBytes: Math.max(1, Number(env.H5_WECHAT_MP_MAX_IMAGE_BYTES ?? 10 * 1024 * 1024)),
    maxFileBytes: Math.max(1, Number(env.H5_WECHAT_MP_MAX_FILE_BYTES ?? 30 * 1024 * 1024)),
    acceptVoice: env.H5_WECHAT_MP_ACCEPT_VOICE !== '0',
    acceptImage: env.H5_WECHAT_MP_ACCEPT_IMAGE !== '0',
    acceptFile: env.H5_WECHAT_MP_ACCEPT_FILE !== '0',
    acceptLocation: env.H5_WECHAT_MP_ACCEPT_LOCATION !== '0',
    acceptLink: env.H5_WECHAT_MP_ACCEPT_LINK !== '0',
    mediaAnalysisGrayUsers: parseCsvList(env.H5_WECHAT_MP_MEDIA_GRAY_USERS),
    reliabilityGrayUsers: parseCsvList(env.H5_WECHAT_MP_RELIABILITY_GRAY_USERS),
    agentReplyTimeoutMs: Math.max(
      0,
      Number(env.H5_WECHAT_MP_AGENT_REPLY_TIMEOUT_MS ?? 15 * 60 * 1000),
    ),
    requireFreshPageThumbnail: env.H5_WECHAT_MP_FRESH_PAGE_THUMBNAILS !== '0',
    repairFreshPageThumbnail: env.H5_WECHAT_MP_FRESH_THUMBNAIL_REPAIR === '1',
    encodingAesKey: env.H5_WECHAT_MP_ENCODING_AES_KEY?.trim() ?? '',
  };
}