import Taro from '@tarojs/taro';
import { fetchClientConfig } from './pay-wechat';

/** 与 package.json version 同步，供服务端 minClientVersion 比对 */
export const APP_VERSION = '3.4.13';

function parseSemver(v: string): number[] {
  return v.split('.').map((n) => parseInt(n, 10) || 0);
}

export function compareSemver(a: string, b: string): number {
  const pa = parseSemver(a);
  const pb = parseSemver(b);
  const len = Math.max(pa.length, pb.length);
  for (let i = 0; i < len; i += 1) {
    const da = pa[i] ?? 0;
    const db = pb[i] ?? 0;
    if (da !== db) return da - db;
  }
  return 0;
}

export async function checkClientVersionGate() {
  try {
    const config = await fetchClientConfig();
    const min = config.minClientVersion?.trim();
    if (min && compareSemver(APP_VERSION, min) < 0) {
      await Taro.showModal({
        title: '版本过低',
        content: '当前小程序版本过低，请更新至最新版本后继续使用。',
        showCancel: false,
        confirmText: '我知道了',
      });
    }
  } catch {
    /* 配置拉取失败不阻塞启动 */
  }
}

export function setupWeappUpdateManager() {
  if (process.env.TARO_ENV !== 'weapp') return;
  if (typeof Taro.getUpdateManager !== 'function') return;

  const manager = Taro.getUpdateManager();
  manager.onCheckForUpdate((res) => {
    if (!res.hasUpdate) return;
    manager.onUpdateReady(() => {
      void Taro.showModal({
        title: '更新提示',
        content: '新版本已准备好，是否重启应用？',
        confirmText: '立即更新',
        success: (r) => {
          if (r.confirm) manager.applyUpdate();
        },
      });
    });
    manager.onUpdateFailed(() => {
      void Taro.showModal({
        title: '更新失败',
        content: '新版本下载失败，请删除小程序后重新搜索打开。',
        showCancel: false,
      });
    });
  });
}

export function initClientVersionChecks() {
  setupWeappUpdateManager();
  void checkClientVersionGate();
}