using LJLib;
using LJProxy.LJLib.Net.SPI.Server;
using LJProxy.Models;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace LJProxy.Excutor
{
    public class GetUpdatePkgExcutor : ExcutorBase<GetUpdatePkgRequest, GetUpdatePkgResponse>
    {
        private static object _syncRoot = new object();
        protected override void ExcuteInternal(GetUpdatePkgRequest request, object state, GetUpdatePkgResponse rslt)
        {
            rslt.ErrCode = "0";

            var apkDirs = @$"{AppDomain.CurrentDomain.BaseDirectory}apk\";
            if (!Directory.Exists(apkDirs))
            {
                rslt.ErrMsg = "apk file folder not exists";
                return;
            }

            //cache file version
            ApkInfo apkInfo = null;
            string cacheKey = "NewestApkData";
            lock (_syncRoot)
            {
                apkInfo = CacheHelper.DefaultCache.Get(cacheKey) as ApkInfo;
                if (apkInfo == null)
                {
                    var dirinfo = new DirectoryInfo(apkDirs);
                    var file = dirinfo.GetFiles()
                        .Where(x => x.Name.EndsWith(".apk", StringComparison.CurrentCultureIgnoreCase))
                        .OrderByDescending(x => x.LastWriteTime).FirstOrDefault();
                    if (file == null)
                    {
                        rslt.ErrMsg = "can not found apk";
                        return;
                    }

                    byte[] apkData = null;
                    using (var fs = file.OpenRead())
                    using (var ms = new MemoryStream())
                    {
                        byte[] buff = new byte[10240];
                        int read = 0;
                        int total = 0;
                        while ((read = fs.Read(buff, 0, buff.Length)) > 0)
                        {
                            ms.Write(buff, 0, read);
                            ms.Flush();
                            total += read;
                        }
                        apkData = ms.ToArray();
                    }

                    APKHelper apkHelper = new APKHelper();
                    var clientVer = apkHelper.GetVersionName(apkData);
                    apkInfo = new ApkInfo();
                    apkInfo.Version = clientVer;
                    apkInfo.ApkData = apkData;
                    //TODO:文件夹缓存依赖不生效，待扩展
                    CacheHelper.DefaultCache.Add(cacheKey, apkInfo, CacheHelper.CreateCacheItemPolicy(null, DateTime.Now.AddMinutes(30), new List<string>() { file.FullName }));
                }
            }

            rslt.Version = apkInfo.Version;
            rslt.ApkData = apkInfo.ApkData;
        }

        public class ApkInfo
        {
            public string Version { get; set; }
            public byte[] ApkData { get; set; }
        }
    }
}