Imports System.IO
Imports System.Net.Http
Imports System.Reflection
Imports System.Runtime.InteropServices
Imports System.Security.Cryptography
Imports System.Text
Imports Newtonsoft.Json.Linq

Module Program
    Sub Main(args As String())
        Console.ForegroundColor = ConsoleColor.Red
        Console.WriteLine(
            "Figyelmeztetés: Ennek az programnak a használatával elfogadod, hogy bármi kárért én nem vállalok felelősséget.")
        Console.WriteLine(
            "Csak saját felhasználásra alkalmas ez a program. (3rd party unofficial Kréta frontend)" + vbCrLf)
        Console.ForegroundColor = ConsoleColor.Gray
        If args.Length > 0 AndAlso args(0) = "schools" Then
            If args.Length > 1 Then
                If args.Length > 2 Then
                    Dim argums = ""
                    For i = 1 To args.Length - 1
                        If i = args.Length - 1 Then
                            argums += args(i)
                        Else
                            argums += args(i) + " "
                        End If
                    Next
                    GetSchools(argums).Wait()
                Else
                    GetSchools(args(1)).Wait()
                End If

            Else
                Console.WriteLine("Nincs elég paraméter! (schools <Iskola neve/azonosítója>)")
            End If
        ElseIf args.Length > 0 AndAlso args(0) = "auth" Then
            if not args.Length > 2 andalso not args(1) = "refresh" andalso not args(1) = "logout" Then
                Console.WriteLine("Nincs elég paraméter! (auth login <felhasználónév>@<iskola-azonosító>)")
                Console.WriteLine("Vagy (auth refresh) ha frissíteni akarod a bejelentkezésed")
                Console.WriteLine("Vagy ha kiszeretnél jelentkezni, (auth logout).")
                exit sub
            end if
            If args(1) = "login" Then
                if not args(2).Contains("@") then
                    Console.WriteLine("Elfelejtetted a @-ot! (auth login <felhasználónév>@<iskola-azonosító>)")
                Else
                    Dim split As String() = args(2).Split("@")
                    Console.WriteLine("Add meg a jelszavad:")
                    Dim password As String = readpassword()
                    getBearer(split(0), password, split(1)).Wait()
                end if
            elseif args(1) = "refresh" Then
                AuthRefreshToken().wait()
            elseif args(1) = "logout" Then
                if not File.Exists(GetStartupPath() + "loginData.json") Then
                    Console.WriteLine("Miért szeretnél kijelentkezni, ha nem is vagy bejelentkezve?")
                    exit sub
                End If
                Console.WriteLine("FIGYELMEZTETÉS: Kijelentkezni készülsz, biztos vagy benne hogy folytatod?")
                Console.WriteLine("i(gen) / n(em) (y/n)")
                Dim answer As String = Console.ReadLine()
                if answer = "i" or answer = "igen" or answer = "y" or answer = "yes" Then
                    Console.WriteLine("UTOLSÓ FIGYELMEZTETÉS: Még mindig ki szeretnél jelentkezni?")
                    Console.WriteLine("Ha igen, akkor írd be az iskolád azonosítóját. (pl. klik06982123)")
                    Dim answer2 As String = ReadPassword()
                    dim logindata as string = GetStartupPath() + "loginData.json"
                    dim jsonString as string = file.ReadAllText(logindata)
                    dim jsonObject as JObject = JObject.Parse(jsonString)
                    dim school as string = jsonObject("institute_code").ToString()
                    if answer2.ToLower() = school.ToLower() Then
                        revokeRefreshToken().Wait()
                        File.Delete(logindata)
                        Console.WriteLine("Sikeresen kijelentkeztél.")
                    Else
                        Console.WriteLine("Az iskolád azonosítója nem egyezik a bejelentkezett iskoládéval.")
                        Console.WriteLine("Kijelentkezés megszakítva.")
                    End If
                end if
            Else
                Console.WriteLine("Nincs elég paraméter! (auth login <felhasználónév>@<iskola-azonosító>)")
                Console.WriteLine("Vagy (auth refresh) ha frissíteni akarod a bejelentkezésed")
                Console.WriteLine("Vagy ha kiszeretnél jelentkezni, (auth logout).")
            End If
        elseif args.Length > 0 andalso args(0) = "help" Then
            Console.WriteLine("KRÉTA CLI " + Version)
            Console.WriteLine(vbcrlf)
            Console.Writeline("Parancsok:")
            Console.ForegroundColor = ConsoleColor.Yellow
            Console.Write("auth ")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.Write("<felhasználónév>@<iskola-azonosító>")
            Console.WriteLine(vbtab + " - Bejelentkezés a fiókba (Token generálás)")
            Console.ForegroundColor = consolecolor.DarkCyan
            Console.Writeline(vbTab + "Példa: hatizsak@klik06982123")
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.Yellow
            Console.Write("auth ")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.Write("refresh")
            Console.WriteLine(vbtab + " - Token frissítése")
            Console.ForegroundColor = ConsoleColor.DarkCyan
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.Yellow
            Console.Write("auth ")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.Write("logout")
            Console.WriteLine(vbtab + " - Kijelentkezés")
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.Yellow
            Console.Write("schools ")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.Write("<Iskola neve/azonosítója>")
            Console.WriteLine(vbtab + " - Iskolák keresése")
            Console.ForegroundColor = ConsoleColor.DarkCyan
            Console.WriteLine(vbTab + "Példa: schools klik")
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.Yellow
            Console.Write("adatlap ")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.Write("<tanulo/gondviselo>")
            Console.WriteLine(vbtab + " - Adatlap lekérése")
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.yellow
            Console.write("changelog")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.WriteLine(vbtab + " - Verzióváltások")
            Console.WriteLine()
            Console.ForegroundColor = ConsoleColor.yellow
            Console.write("privacy")
            Console.ForegroundColor = ConsoleColor.Gray
            Console.WriteLine(vbtab + " - Adatvédelmi cucc (idk mi a neve)")
            Console.WriteLine()
        Elseif args.Length > 0 andalso args(0) = "adatlap" Then
            if args.Length > 1 Then
                if args(1) = "tanulo" Then
                    TanuloiAdatlap().Wait()
                elseif args(1) = "gondviselo" Then
                    Console.WriteLine("Ha tanulói fiókkal vagy ez nagy eséllyel nem fog menni." + vbcrlf)
                    GondviseloiAdatlap().wait()
                Else
                    Console.WriteLine("Ismeretlen paraméter! (adatlap <tanulo/gondviselo>)")
                End If
            Else
                Console.WriteLine("Nincs elég paraméter! (adatlap <tanulo/gondviselo>)")
            End If
        elseif args.Length > 0 andalso args(0) = "changelog" then
            Console.WriteLine(Readonlymodule.Changelog)
        elseif args.Length > 0 andalso args(0) = "privacy" Then
            Console.WriteLine(Readonlymodule.Privacy)
        Else
            Console.WriteLine("Ismeretlen parancs, kérlek használd a segítséget. (help)")
        End If
    End Sub

    Private Function GetSchools(search As String) As Task
        Dim task As Task = Task.Run(
            Sub()
                dim path as string = GetStartupPath() + "schools.json"
                Dim lastWriteTime As DateTime = File.GetLastWriteTime(path)
                Dim timediff As TimeSpan = DateTime.Now.Subtract(lastWriteTime)
                If File.Exists(path) AndAlso timediff.TotalHours < 10 AndAlso Not timediff.TotalHours < 0 Then
                    Dim schools As String = File.ReadAllText(path)
                    Console.ForegroundColor = ConsoleColor.DarkGreen
                    Console.WriteLine("Volt egy már cachelt változat, ami {0} órája volt letöltve.",
                                      timediff.TotalHours.ToString("0.0"))
                    Console.ForegroundColor = ConsoleColor.Gray
                    Dim sarray = ""
                    Dim searchIndex As Integer = schools.ToLower.IndexOf(search.ToLower, StringComparison.Ordinal)
                    If searchIndex = - 1 Then
                        Console.WriteLine("Nincs találat, próbálj valami mást.")
                    Else
                        searchIndex = 0
                        Dim jArray As JArray = JArray.Parse(schools)
                        For Each jObject As JObject In jArray
                            Dim nev As String = jObject("nev").ToString().ToLower()
                            Dim azonosito As String = jObject("azonosito").ToString().ToLower()
                            Dim found = False
                            If nev.Contains(search.ToLower, StringComparison.CurrentCultureIgnoreCase) Then
                                searchIndex += 1
                                sarray += jObject.ToString
                                found = True
                            End If
                            If found = False Then
                                If azonosito.Contains(search.ToLower, StringComparison.CurrentCultureIgnoreCase) _
                                       Then
                                    searchIndex += 1
                                    sarray += jObject.ToString
                                End If
                            End If
                        Next
                        If searchIndex = 1 Then
                            Console.WriteLine(sarraygen(sarray))
                        Else
                            Dim arrays As String() = sarray.Split("}{").ToArray
                            Dim number = 0
                            For Each sarray In arrays
                                number += 1
                                Console.WriteLine(vbCrLf + "{0}. Találat", number.ToString)
                                Console.WriteLine(sarraygen(sarray))
                            Next
                            Console.WriteLine(vbCrLf)
                            Console.WriteLine("A parancs 1-nél több iskolát ({0}) talált.", number.ToString)
                            Console.WriteLine("Ha lehet kicsit specifikusabban add meg a nevét!")
                        End If
                    End If
                Else
                    Dim client = New HttpClient()
                    client.DefaultRequestHeaders.Add("api-version", "v1")
                    Dim response As HttpResponseMessage =
                            client.GetAsync("https://kretaglobalapi.e-kreta.hu/intezmenyek/kreta/publikus").Result
                    If response.IsSuccessStatusCode Then
                        Dim schools As String = response.Content.ReadAsStringAsync().Result
                        File.Delete(path)
                        File.WriteAllText(path, schools)
                        Dim sarray = ""
                        Dim searchIndex As Integer = schools.ToLower.IndexOf(search.ToLower,
                                                                             StringComparison.Ordinal)
                        If searchIndex = - 1 Then
                            Console.WriteLine("Nincs találat, próbálj valami mást.")
                        Else
                            searchIndex = 0
                            Dim jArray As JArray = JArray.Parse(schools)
                            For Each jObject As JObject In jArray
                                Dim nev As String = jObject("nev").ToString().ToLower()
                                Dim azonosito As String = jObject("azonosito").ToString().ToLower()
                                Dim found = False
                                If nev.Contains(search.ToLower, StringComparison.CurrentCultureIgnoreCase) Then
                                    searchIndex += 1
                                    sarray += jObject.ToString
                                    found = True
                                End If
                                If found = False Then
                                    If azonosito.Contains(search.ToLower, StringComparison.CurrentCultureIgnoreCase) _
                                       Then
                                        searchIndex += 1
                                        sarray += jObject.ToString
                                    End If
                                End If
                            Next
                            If searchIndex = 1 Then
                                Console.WriteLine(sarraygen(sarray))
                            Else
                                Dim arrays As String() = sarray.Split("}{").ToArray
                                Dim number = 0
                                For Each sarray In arrays
                                    number += 1
                                    Console.WriteLine(vbCrLf + "{0}. Találat", number.ToString)
                                    Console.WriteLine(sarraygen(sarray.ToString()))
                                Next
                                Console.WriteLine(vbCrLf)
                                Console.WriteLine("A parancs 1-nél több iskolát ({0}) talált.", number.ToString)
                                Console.WriteLine("Ha lehet kicsit specifikusabban add meg a nevét!")
                            End If
                        End If
                    Else
                        Console.WriteLine("Hiba, {0}", response.StatusCode)
                    End If

                End If
            End Sub)
        Return task
    End Function

    Private Function SarrayGen(stringarray As String)
        Dim str As String = stringarray.Replace("  ", "").Replace(": ", ":")
        dim list
        if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) then
            list = New List(Of String)(str.Split(New String() {vbCrLf}, StringSplitOptions.None))
        Else
            list = New List(Of String)(str.Split(New String() {vbLf}, StringSplitOptions.None))
        end if
        dim azonosito as string =
                list.Item(2).Replace("""azonosito"":""", "Azonosító: ").Replace(""",", "").Replace(vbCrLf, "").
                ToString
        dim nev as String =
                list.Item(3).Replace("""nev"":""", "Név: ").Replace(""",", "").Replace(vbCrLf, "").ToString
        If nev.Contains("\""") Then
            nev = nev.Replace("\""", "")
        End If
        dim link as String =
                list.Item(6).Replace("""kretaLink"":""", "Link: ").Replace(""",", "").Replace(vbCrLf, "").ToString
        Dim final As String = vbCrLf + azonosito + vbCrLf + nev + vbCrLf + link
        Return final
    End Function

    Private Function GetNonce()
        Dim nonce = ""
        Dim client = New HttpClient()
        Dim response As HttpResponseMessage = client.GetAsync("https://idp.e-kreta.hu/nonce").Result
        If response.IsSuccessStatusCode Then
            nonce = response.Content.ReadAsStringAsync().Result
        Else
            Console.WriteLine("Hiba, {0}", response.StatusCode)
        End If
        Return nonce
    End Function

    Private Function GetStartupPath() As String
        dim path as string = IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)
        if RuntimeInformation.IsOSPlatform(OSPlatform.Windows) Then
            path = path + "\"
        Else
            path = path + "/"
        End if
        Return path
    End Function
    ' megfogom ölni magam
    Private Function GetBearer(username As String, password As String, instituteCode As String) As Task
        Dim task As Task = Task.Run(
            Sub()
                Dim client = New HttpClient()
                Dim nonce As String = getNonce()
                Dim authpoolkey As String = GenAuthorizationPolicy(username, institutecode, nonce)
                Dim content = New FormUrlEncodedContent(New Dictionary(Of String, String) From {
                                                           {"userName", username},
                                                           {"password", password},
                                                           {"institute_code", institutecode},
                                                           {"grant_type", "password"},
                                                           {"client_id", "kreta-ellenorzo-mobile-android"}
                                                           })
                client.DefaultRequestHeaders.Add("X-Authorizationpolicy-Key", authpoolkey)
                client.DefaultRequestHeaders.Add("X-Authorizationpolicy-Version", "v2")
                client.DefaultRequestHeaders.Add("X-Authorizationpolicy-Nonce", nonce)
                Dim response As HttpResponseMessage =
                        client.PostAsync("https://idp.e-kreta.hu/connect/token", content).Result
                If response.IsSuccessStatusCode Then
                    Dim result As String = response.Content.ReadAsStringAsync.Result
                    Console.WriteLine("Sikeres lekérés mentve.")
                    Try
                        Dim path As String = GetStartupPath() + "login.json"
                        File.Delete(path)
                        File.WriteAllText(path, result)
                        path = GetStartupPath() + "loginData.json"
                        File.Delete(path)
                        Dim jObject As JObject = JObject.Parse(result)
                        Dim token As String = jObject("access_token").ToString()
                        Dim refreshToken As String = jObject("refresh_token").ToString()
                        Dim json As String = "{""access_token"":""" + token + """," + vbCrLf + """refresh_token"":""" +
                                             refreshToken + """," + vbCrLf + """institute_code"":""" + instituteCode +
                                             """}"
                        File.WriteAllText(path, json)
                        File.Delete(GetStartupPath() + "login.json")
                    Catch ex As Exception
                        Console.WriteLine("Hiba történt a mentés során.")
                        Exit Try
                    End Try
                    Console.WriteLine("Adatok elmentve!")
                Else
                    Console.WriteLine("Hiba, {0}", response.StatusCode)
                    Console.WriteLine("{0}", response.Content.ReadAsStringAsync().Result)
                End If
            End Sub)
        Return task
    End Function

    Private Function GenAuthorizationPolicy(username As String, institutecode As String, nonce As String)
        Const hmacKey = "baSsxOwlU1jM"
        Dim hmac = New HMACSHA512(Encoding.UTF8.GetBytes(hmacKey))
        Dim unenc As String = institutecode.ToUpper + nonce + username.ToUpper
        Dim enc As Byte() = hmac.ComputeHash(Encoding.UTF8.GetBytes(unenc))
        Dim base64 As String = Convert.ToBase64String(enc)
        Return base64
    End Function

    private function TanuloiAdatlap() as task
        dim task as task = task.run(Sub()
            Dim lastWriteTime As DateTime = File.GetLastWriteTime(getstartuppath + "diakadatlap.json")
            Dim timediff As TimeSpan = DateTime.Now.Subtract(lastWriteTime)
            if _
                                       File.Exists(getstartuppath + "diakadatlap.json") AndAlso timediff.TotalHours < 10 AndAlso
                                       Not timediff.TotalHours < 0 Then
                Dim diakadatlap As String = File.ReadAllText(getstartuppath + "diakadatlap.json")
                Console.ForegroundColor = ConsoleColor.DarkGreen
                Console.WriteLine("Volt egy már cachelt változat, ami {0} órája volt letöltve.",
                                  timediff.TotalHours.ToString("0.0"))
                Console.ForegroundColor = ConsoleColor.Gray
                Console.WriteLine(diakadatlap)
            Else
                dim client = new HttpClient()
                dim apikey = "21ff6c25-d1da-4a68-a811-c881a6057463"
                client.DefaultRequestHeaders.Add("apiKey", apikey)
                dim path as string = GetStartupPath() + "loginData.json"
                dim token as string
                dim school as string
                if File.Exists(path) Then
                    dim jsonString as string = file.ReadAllText(path)
                    dim jsonObject as JObject = JObject.Parse(jsonString)
                    token = jsonObject("access_token").ToString()
                    school = jsonObject("institute_code").ToString()
                Else
                    Console.WriteLine("Jelenleg nem vagy authentikálva / nem található a loginData.json fájl.")
                    Console.WriteLine("Kérlek használd az auth parancsot.")
                    exit sub
                End If
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token)
                dim response as HttpResponseMessage =
                        client.GetAsync("https://" + school + ".e-kreta.hu/ellenorzo/v3/sajat/TanuloAdatlap").Result
                if response.IsSuccessStatusCode Then
                    dim savepath as string = getstartuppath + "diakadatlap.json"
                    Dim result As String = response.Content.ReadAsStringAsync.Result
                    File.Delete(savepath)
                    File.WriteAllText(savepath, result)
                    Console.WriteLine(result)
                Else
                    Console.WriteLine("Hiba, {0}", response.StatusCode)
                    Console.WriteLine("{0}", response.Content.ReadAsStringAsync().Result)
                End If
            End If
        end sub)
        return task
    End function

    private function GondviseloiAdatlap() as task
        dim task as task = task.run(Sub()
            Dim lastWriteTime As DateTime = File.GetLastWriteTime(getstartuppath + "szuloadatlap.json")
            Dim timediff As TimeSpan = DateTime.Now.Subtract(lastWriteTime)
            if file.Exists(getstartuppath + "szuloadatlap.json") AndAlso timediff.TotalHours < 10 AndAlso
               Not timediff.TotalHours < 0 Then
                dim szuloadatlap as string = file.ReadAllText(getstartuppath + "szuloadatlap.json")
                Console.ForegroundColor = ConsoleColor.DarkGreen
                Console.WriteLine("Volt egy már cachelt változat, ami {0} órája volt letöltve.",
                                  timediff.TotalHours.ToString("0.0"))
                Console.ForegroundColor = ConsoleColor.Gray
                Console.WriteLine(szuloadatlap)
            Else
                dim client = new HttpClient()
                dim apikey = "21ff6c25-d1da-4a68-a811-c881a6057463"
                client.DefaultRequestHeaders.Add("apiKey", apikey)
                dim path as string = GetStartupPath() + "loginData.json"
                dim token as string
                dim school as string
                if File.Exists(path) Then
                    dim jsonString as string = file.ReadAllText(path)
                    dim jsonObject as JObject = JObject.Parse(jsonString)
                    token = jsonObject("access_token").ToString()
                    school = jsonObject("institute_code").ToString()
                Else
                    Console.WriteLine("Jelenleg nem vagy authentikálva / nem található a loginData.json fájl.")
                    Console.WriteLine("Kérlek használd az auth parancsot.")
                    exit sub
                End If
                client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token)
                dim response as HttpResponseMessage =
                        client.GetAsync("https://" + school + ".e-kreta.hu/ellenorzo/v3/sajat/GondviseloAdatlap").Result
                if response.IsSuccessStatusCode Then
                    dim savepath as string = getstartuppath + "szuloadatlap.json"
                    Dim result As String = response.Content.ReadAsStringAsync.Result
                    File.Delete(savepath)
                    File.WriteAllText(savepath, result)
                    Console.WriteLine(result)
                Else
                    if response.StatusCode.ToString() = "Forbidden" Then
                        Console.WriteLine("Használj inkább tanulói adatlapot! (adatlap tanulo)")
                    End If
                    Console.WriteLine("Hiba, {0}", response.StatusCode)
                    Console.WriteLine("{0}", response.Content.ReadAsStringAsync().Result)
                End If
            End If
        end sub)
        return task
    End function

    private function AuthRefreshToken() as task
        dim task as task = Task.run(
            Sub()
                dim client = new HttpClient()
                dim path as string = GetStartupPath() + "loginData.json"
                dim refreshtok as string
                dim institutecode as string
                if File.Exists(path) Then
                    dim jsonString as string = file.ReadAllText(path)
                    dim jsonObject as JObject = JObject.Parse(jsonString)
                    refreshtok = jsonObject("refresh_token").ToString()
                    institutecode = jsonObject("institute_code").ToString()
                Else
                    Console.WriteLine("Nem voltál authentikálva / nem található a loginData.json fájl.")
                    Console.WriteLine("Kérlek használd az auth parancsot.")
                    exit sub
                End If
                Dim content = New FormUrlEncodedContent(New Dictionary(Of String, String) From {
                                                           {"institute_code", institutecode},
                                                           {"refresh_token", refreshtok},
                                                           {"grant_type", "refresh_token"},
                                                           {"client_id", "kreta-ellenorzo-mobile-android"}
                                                           })
                dim response as HttpResponseMessage =
                        client.PostAsync("https://idp.e-kreta.hu/connect/token", content).Result
                If response.IsSuccessStatusCode Then
                    Dim result As String = response.Content.ReadAsStringAsync.Result
                    Console.WriteLine("Sikeres lekérés mentve.")
                    Try
                        path = GetStartupPath() + "login.json"
                        File.Delete(path)
                        File.WriteAllText(path, result)
                        path = GetStartupPath() + "loginData.json"
                        File.Delete(path)
                        Dim jObject As JObject = JObject.Parse(result)
                        Dim token As String = jObject("access_token").ToString()
                        Dim refreshToken As String = jObject("refresh_token").ToString()
                        Dim json As String = "{""access_token"":""" + token + """," + vbCrLf + """refresh_token"":""" +
                                             refreshToken + """," + vbCrLf + """institute_code"":""" + instituteCode +
                                             """}"
                        File.WriteAllText(path, json)
                        file.Delete(GetStartupPath() + "login.json")
                    Catch ex As Exception
                        Console.WriteLine("Hiba történt a mentés során.")
                        Exit Try
                    End Try
                    Console.WriteLine("Adatok elmentve!")
                Else
                    Console.WriteLine("Hiba, {0}", response.StatusCode)
                    Console.WriteLine("{0}", response.Content.ReadAsStringAsync().Result)
                End If
            end sub)
        return task
    End function

    private Function ReadPassword() As String
        Dim password As New System.Text.StringBuilder()
        While True
            Dim info As ConsoleKeyInfo = Console.ReadKey(True)
            If info.Key = ConsoleKey.Enter Then
                Console.WriteLine()
                Exit While
            ElseIf info.Key = ConsoleKey.Backspace Then
                If password.Length > 0 Then
                    password.Remove(password.Length - 1, 1)
                    Console.Write(vbBack)
                    Console.Write(" ")
                    Console.Write(vbBack)
                End If
            Else
                password.Append(info.KeyChar)
                Console.Write("*")
            End If
        End While
        Return password.ToString()
    End Function

    private function RevokeRefreshToken() as Task
        dim task as task = task.run(
            Sub()
                dim client = new HttpClient()
                dim path as string = GetStartupPath() + "loginData.json"
                dim refreshtok as string
                if File.Exists(path) Then
                    dim jsonString as string = file.ReadAllText(path)
                    dim jsonObject as JObject = JObject.Parse(jsonString)
                    refreshtok = jsonObject("refresh_token").ToString()
                Else
                    exit sub
                End If
                Dim content = New FormUrlEncodedContent(New Dictionary(Of String, String) From {
                                                           {"token", refreshtok},
                                                           {"client_id", "kreta-ellenorzo-mobile-android"}
                                                           })
                dim response as HttpResponseMessage =
                        client.PostAsync("https://idp.e-kreta.hu/connect/revocation", content).Result
                If response.IsSuccessStatusCode Then
                    Console.WriteLine("Refresh token érvénytelenítve.")
                Else
                    Console.WriteLine("Hiba, {0}", response.StatusCode)
                    Console.WriteLine("{0}", response.Content.ReadAsStringAsync().Result)
                End If
            end sub)
        return task
    End function
End Module