LJProxy/Services/VersionService.cs

using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace LJProxy.Services
{
    public class VersionService:ServiceBase
    {
        private static object _updateJsonSyncRoot = new object();
        private static object _apkSyncRoot = new object();

        public string GetUpdateJson()
        {
            string updateJson = string.Empty;
            string key = "UpdateJson";
            lock (_updateJsonSyncRoot)
            {
                updateJson = Cache.DefaultCache.Get(key) as string;
                if (string.IsNullOrEmpty(updateJson))
                {
                    string updateJsonPath = @$"{AppDomain.CurrentDomain.BaseDirectory}apk\update.json";
                    updateJson = System.IO.File.ReadAllText(updateJsonPath, Encoding.UTF8);
                    Cache.DefaultCache.Add(key, updateJson, Cache.CreateCacheItemPolicy(null, DateTime.Now.AddMinutes(30), new List<string>() { updateJsonPath }));
                }
            }
            return updateJson;
        }


        public byte[] GetAPK(string apkName)
        {
            if (string.IsNullOrEmpty(apkName)) return null;
            var updateJson = GetUpdateJson();
            var updateInfoObj = JObject.Parse(updateJson);
            string url = updateInfoObj["url"]?.ToString();
            if (string.IsNullOrEmpty(url))
            {
                return null;
            }
            Regex regx = new Regex(@"GetAppUpdate/(?<apkName>.*?\.apk)", RegexOptions.IgnoreCase);
            var matchResult = regx.Match(url);
            if (matchResult.Success)
            {
                var jsonApkName = matchResult.Groups["apkName"]?.Value;
                if (!apkName.Equals(jsonApkName, StringComparison.OrdinalIgnoreCase)) return null;
                string key = apkName.ToLower();
                byte[] result = null;
                lock (_apkSyncRoot)
                {
                    result = Cache.DefaultCache.Get(key) as byte[];
                    if (result == null)
                    {
                        string apkFilePath = @$"{AppDomain.CurrentDomain.BaseDirectory}apk\{apkName}";
                        if (!System.IO.File.Exists(apkFilePath))
                        {
                            return null;
                        }
                        result = System.IO.File.ReadAllBytes(apkFilePath);
                        Cache.DefaultCache.Add(key, result, Cache.CreateCacheItemPolicy(null, DateTime.Now.AddMinutes(30), new List<string>() { apkFilePath }));
                    }
                }
                return result;
            }
            return null;
        }
    }
}