refactor<*>: rewrite all codes...

src/Commands/SaveRevisionFile.cs

@@ -0,0 +1,44 @@
+using System.Diagnostics;
+using System.IO;
+
+namespace SourceGit.Commands {
+    /// <summary>
+    ///     保存指定版本的文件
+    /// </summary>
+    public class SaveRevisionFile {
+        private string cwd = "";
+        private string bat = "";
+
+        public SaveRevisionFile(string repo, string path, string sha, string saveTo) {
+            var tmp = Path.GetTempFileName();
+            var cmd = $"\"{Models.Preference.Instance.Git.Path}\" --no-pager ";
+
+            var isLFS = new IsLFSFiltered(repo, path).Result();
+            if (isLFS) {
+                cmd += $"show {sha}:\"{path}\" > {tmp}.lfs\n";
+                cmd += $"\"{Models.Preference.Instance.Git.Path}\" --no-pager lfs smudge < {tmp}.lfs > \"{saveTo}\"\n";
+            } else {
+                cmd += $"show {sha}:\"{path}\" > \"{saveTo}\"\n";
+            }
+
+            cwd = repo;
+            bat = tmp + ".bat";
+
+            File.WriteAllText(bat, cmd);
+        }
+
+        public void Exec() {
+            var starter = new ProcessStartInfo();
+            starter.FileName = bat;
+            starter.WorkingDirectory = cwd;
+            starter.CreateNoWindow = true;
+            starter.WindowStyle = ProcessWindowStyle.Hidden;
+
+            var proc = Process.Start(starter);
+            proc.WaitForExit();
+            proc.Close();
+
+            File.Delete(bat);
+        }
+    }
+}