update structure

ModpackUpdater.Model/ModpackInfo.vb

@@ -0,0 +1,30 @@
+Imports System.IO
+
+Imports Newtonsoft.Json
+Imports Newtonsoft.Json.Converters
+Imports Newtonsoft.Json.Linq
+
+Public Class ModpackInfo
+
+    Private Const FILENAME_MODPACKINFO = "modpack-info.json"
+
+    <JsonConverter(GetType(VersionConverter))>
+    Public Property Version As Version
+
+    Public Sub Save(mcRoot As String)
+        File.WriteAllText(GetFilePath(mcRoot), JObject.FromObject(Me).ToString)
+    End Sub
+
+    Public Shared Function Load(mcRoot As String) As ModpackInfo
+        Return JObject.Parse(File.ReadAllText(GetFilePath(mcRoot))).ToObject(Of ModpackInfo)
+    End Function
+
+    Public Shared Function HasModpackInfo(mcRoot As String) As Boolean
+        Return File.Exists(GetFilePath(mcRoot))
+    End Function
+
+    Private Shared Function GetFilePath(mcRoot As String)
+        Return Path.Combine(mcRoot, FILENAME_MODPACKINFO)
+    End Function
+
+End Class