import 'dart:io';

import 'package:get/get.dart';

import '../config/config.dart';
import '../hj_model/splash/domain_source_model.dart';

///启动页 /ping/domain 下发的当前平台版本信息，冷启动必刷新，不落磁盘
CheckVersionInfo? _remoteVersion;

///启动页拿到配置后调一次，筛出当前平台那条存内存
void saveVersion(List<CheckVersionInfo> versions) {
  final os = Platform.operatingSystem;
  _remoteVersion = versions.firstWhereOrNull((e) => e.platform?.toLowerCase() == os);
}

///有新版本则返回版本信息，已是最新 / 没配置都返回 null；只读内存，不发请求
CheckVersionInfo? checkUpdate() {
  final info = _remoteVersion;
  if (info == null) return null;
  return compareVersion(Config.innerVersion, info.verName ?? '') ? info : null;
}

///比较版本号：newVersion 比 version 新则返回 true（需更新）
bool compareVersion(String version, String newVersion) {
  List<String> localArr = version.split(".");
  List<String> newArr = newVersion.split(".");
  //逐位比较，最多比较前 3 段（major.minor.patch），按两者较短的段数取，避免越界
  int count = newArr.length < localArr.length ? newArr.length : localArr.length;
  if (count > 3) count = 3;
  for (int i = 0; i < count; i++) {
    int newCode = int.tryParse(newArr[i]) ?? 0;
    int localCode = int.tryParse(localArr[i]) ?? 0;
    if (newCode > localCode) return true;
    if (newCode < localCode) return false;
  }
  return false;
}