using System;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using NewLife;
using NewLife.Log;
using NewLife.Web;

namespace XCoder
{
 /// <summary>GTK助手,自动检查安装GTK运行时</summary>
 public class GtkHelper
 {
 #region 属性
 public String GtkRoot { get; set; }

 public String GtkPath { get; set; }

 public Version Version { get; set; }
 #endregion

 #region 主要方法
 public static Task CheckRuntime(Int32 msTimeout = 3_000)
 {
 var task = Task.Run(async () =>
 {
 var gtk = new GtkHelper { Log = XTrace.Log };
 if (!gtk.Check()) await gtk.DownloadAsync();

 gtk.Install();
 });
 // 最多等3秒
 task.Wait(msTimeout);

 return task;
 }

 /// <summary>检查是否安装有GTK运行时</summary>
 /// <returns></returns>
 public Boolean Check()
 {
 // 只处理Windows
 if (!Runtime.Windows) return true;

 // LOCALDATA
 if (GtkRoot.IsNullOrEmpty())
 {
 var data = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
 GtkRoot = data.CombinePath("Gtk").GetFullPath();
 }
 //XTrace.WriteLine("查找GTK运行时:{0}", GtkRoot);

 var di = GtkRoot.AsDirectory();
 if (!di.Exists) return false;

 var dis = di.GetDirectories();
 if (dis == null || dis.Length == 0) return false;

 //var gtk = dis.OrderByDescending(e => e.Name).FirstOrDefault();
 //GtkPath = gtk.FullName;
 //Version = new Version(gtk.Name.TrimStart('v', 'V'));
 foreach (var item in dis)
 {
 var gtk = item.FullName.CombinePath("libgdk-3-0.dll");
 if (File.Exists(gtk))
 {
 GtkPath = item.FullName;

 try
 {
 Version = new Version(item.Name.TrimStart('v', 'V'));
 }
 catch { }

 break;
 }
 }

 if (GtkPath.IsNullOrEmpty()) return false;

 XTrace.WriteLine("发现GTK运行时:[{0}] {1}", Version, GtkPath);

 return true;
 }

 /// <summary>下载</summary>
 /// <returns></returns>
 public async Task<Boolean> DownloadAsync()
 {
 var set = NewLife.Setting.Current;

 //var client = new WebClientX
 //{
 // Log = XTrace.Log
 //};

 //var links = client.GetLinks(set.PluginServer);
 //var lnk = links.First(e => e.Name.EqualIgnoreCase("Gtk"));

 //var file = client.DownloadLink(set.PluginServer, "Gtk", GtkRoot);
 var file = await DownloadLinkAsync(set.PluginServer, "Gtk", GtkRoot);
 var link = new Link();
 link.Parse(file);

 XTrace.WriteLine("版本:{0}", link.Version);

 //client.DownloadLinkAndExtract(set.PluginServer, "Gtk", gtk, true);

 GtkPath = GtkRoot.CombinePath(link.Version + "");
 Version = link.Version;

 Extract(file, GtkPath, true);

 return true;
 }

 /// <summary>安装</summary>
 public void Install()
 {
 if (!GtkPath.IsNullOrEmpty()) SetDllDirectory(GtkPath);
 }
 #endregion

 #region 辅助
 /// <summary>分析指定页面指定名称的链接,并下载到目标目录,返回目标文件</summary>
 /// <remarks>
 /// 根据版本或时间降序排序选择
 /// </remarks>
 /// <param name="urls">指定页面</param>
 /// <param name="name">页面上指定名称的链接</param>
 /// <param name="destdir">要下载到的目标目录</param>
 /// <returns>返回已下载的文件,无效时返回空</returns>
 private async Task<String> DownloadLinkAsync(String urls, String name, String destdir)
 {
 Log.Info("下载链接 {0},目标 {1}", urls, name);

 var names = name.Split(",", ";");

 var file = "";
 Link link = null;
 Exception lastError = null;
 foreach (var url in urls.Split(",", ";"))
 {
 try
 {
 var http = new HttpClient();
 var html = await http.GetStringAsync(url);
 var ls = Link.Parse(html, url);
 if (ls.Length == 0) return file;

 // 过滤名称后降序排序,多名称时,先确保前面的存在,即使后面名称也存在并且也时间更新都不能用
 foreach (var item in names)
 {
 link = ls.Where(e => !e.Url.IsNullOrWhiteSpace())
 .Where(e => e.Name.EqualIgnoreCase(item) || e.FullName.Equals(item))
 .OrderByDescending(e => e.Version)
 .ThenByDescending(e => e.Time)
 .FirstOrDefault();
 if (link != null) break;
 }
 }
 catch (Exception ex)
 {
 lastError = ex;
 }
 if (link != null) break;
 }
 if (link == null)
 {
 if (lastError != null) throw lastError;

 return file;
 }

 var linkName = link.FullName;
 var file2 = destdir.CombinePath(linkName).EnsureDirectory();

 // 已经提前检查过,这里几乎不可能有文件存在
 if (File.Exists(file2))
 {
 // 如果连接名所表示的文件存在,并且带有时间,那么就智能是它啦
 var p = linkName.LastIndexOf("_");
 if (p > 0 && (p + 8 + 1 == linkName.Length || p + 14 + 1 == linkName.Length))
 {
 Log.Info("分析得到文件 {0},目标文件已存在,无需下载 {1}", linkName, link.Url);
 return file2;
 }
 }

 Log.Info("分析得到文件 {0},准备下载 {1},保存到 {2}", linkName, link.Url, file2);
 // 开始下载文件,注意要提前建立目录,否则会报错
 file2 = file2.EnsureDirectory(true);

 var sw = Stopwatch.StartNew();
 {
 var http = new HttpClient();
 var ns = await http.GetStreamAsync(link.Url);
 using var fs = File.OpenWrite(file2);
 await ns.CopyToAsync(fs);
 }
 //TaskEx.Run(() => DownloadFileAsync(link.Url, file2)).Wait();
 sw.Stop();

 if (File.Exists(file2))
 {
 Log.Info("下载完成,共{0:n0}字节,耗时{1:n0}毫秒", file2.AsFile().Length, sw.ElapsedMilliseconds);
 file = file2;
 }

 return file;
 }

 /// <summary>分析指定页面指定名称的链接,并下载到目标目录,解压Zip后返回目标文件</summary>
 /// <param name="urls">提供下载地址的多个目标页面</param>
 /// <param name="name">页面上指定名称的链接</param>
 /// <param name="destdir">要下载到的目标目录</param>
 /// <param name="overwrite">是否覆盖目标同名文件</param>
 /// <returns></returns>
 private String Extract(String file, String destdir, Boolean overwrite = false)
 {
 if (file.IsNullOrEmpty()) return null;

 // 解压缩
 try
 {
 Log.Info("解压缩到 {0}", destdir);
 //ZipFile.ExtractToDirectory(file, destdir);
 file.AsFile().Extract(destdir, overwrite);

 // 删除zip
 File.Delete(file);

 return file;
 }
 catch (Exception ex)
 {
 Log.Error(ex?.GetTrue()?.ToString());

 // 这个时候出现异常,删除zip
 if (!file.IsNullOrEmpty() && File.Exists(file))
 {
 try
 {
 File.Delete(file);
 }
 catch { }
 }
 }

 return null;
 }

 [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
 static extern Int32 SetDllDirectory(String pathName);
 #endregion

 #region 日志
 public ILog Log { get; set; } = Logger.Null;

 public void WriteLog(String format, params Object[] args) => Log?.Info(format, args);
 #endregion
 }
}