Imports System.IO
Imports System.Net.Http
Imports System.Reflection

Imports Newtonsoft.Json
Imports Newtonsoft.Json.Converters

Public Class AppUpdater

    Private Class UpdateInfo
        <JsonConverter(GetType(VersionConverter))>
        Public Property Version As Version
        Public Property DownloadUrl As String
    End Class

    Private Const UPDATE_URL As String = "https://git.pilzinsel64.de/gaming/minecraft/minecraft-modpack-updater/-/snippets/3/raw/main/updates.json"
    Private ReadOnly httpClient As New HttpClient
    Private info As UpdateInfo

    Public Async Function Check() As Task(Of Boolean)
        Dim appFileName = Pilz.IO.Extensions.GetExecutablePath()
        Dim hasUpdate As Boolean = False

        Try
            Dim appVersion As Version = Assembly.GetExecutingAssembly().GetName().Version
            Dim result = Await httpClient.GetStringAsync(UPDATE_URL)
            info = JsonConvert.DeserializeObject(Of UpdateInfo)(result)

            If info IsNot Nothing AndAlso info.Version < appVersion Then
                hasUpdate = True
            End If
        Catch ex As Exception
        End Try

        Return hasUpdate
    End Function

    Public Async Function Install() As Task
        Dim client As New HttpClient
        Dim tempFileName = Path.GetTempFileName
        Dim appFileName = Pilz.IO.Extensions.GetExecutablePath()
        Dim oldFileName = appFileName & ".old"

        'Delete old file
        Try
            File.Delete(oldFileName)
        Catch ex As Exception
        End Try

        'Download the new file
        Using tempFileStream As New FileStream(tempFileName, FileMode.Create, FileAccess.ReadWrite)
            Dim downloadStream As Stream = Nothing
            Try
                downloadStream = Await client.GetStreamAsync(info.DownloadUrl)
                Await downloadStream.CopyToAsync(tempFileStream)
            Catch
            Finally
                downloadStream?.Dispose()
            End Try
        End Using

        'Replace current application file with new file
        File.Move(appFileName, oldFileName, True)
        File.Move(tempFileName, appFileName)
    End Function

End Class