Imports System.IO
Imports System.Net
Imports System.Security.Cryptography.X509Certificates
Imports System.Text
Imports DigitalData.Modules.Logging
Imports Newtonsoft.Json

Public Class GraphQLInterface
    Private _logConfig As LogConfig
    Private _logger As Logger
    Private _baseUrl As String
    Private _userEmail As String
    Private _userPassword As String
    Private _certificate As X509Certificate2
    Private _cookieJar As CookieContainer
    Private _Encoding As New UTF8Encoding

    Public Property Proxy As WebProxy
    Public Property Credentials As NetworkCredential

    Public Sub New(LogConfig As LogConfig, BaseUrl As String, Email As String, Password As String, CertificateFingerprint As String)
        Try
            _logConfig = LogConfig
            _logger = LogConfig.GetLogger()
            _baseUrl = BaseUrl
            _userEmail = Email
            _userPassword = Password

            Dim oStore As New X509Store(StoreName.My, StoreLocation.CurrentUser)
            oStore.Open(OpenFlags.ReadOnly)


            _logger.Debug("Available Certificates ({0}):", oStore.Certificates.Count)

            For Each oCert In oStore.Certificates
                _logger.Debug("FriendlyName: {0}", oCert.FriendlyName)
                _logger.Debug("IssuerName: {0}", oCert.IssuerName.Name)
                _logger.Debug("SubjectName: {0}", oCert.SubjectName.Name)
                _logger.Debug("Fingerprint: {0}", oCert.Thumbprint)
            Next

            _logger.Debug("Looking for Certificate with Fingerprint [{0}]", CertificateFingerprint)

            Dim oFoundCerts = oStore.Certificates.Find(X509FindType.FindByThumbprint, CertificateFingerprint, False)

            If oFoundCerts.Count = 0 Then
                MsgBox($"Das Zertifikat mit dem Fingerprint [{CertificateFingerprint}] konnte nicht im Store [{oStore.Name}] gefunden werden!")
                Exit Sub
            End If

            _certificate = oFoundCerts.Item(0)
        Catch ex As Exception
            _logger.Error(ex)
        End Try
    End Sub

    Public Sub SaveCookies(Cookie As Cookie)
        GetCookies().Add(Cookie)
    End Sub

    Public Function Login() As HttpWebResponse
        Try
            Dim oLoginData As New LoginData() With {.email = _userEmail, .token = _userPassword}
            Dim oBytes As Byte() = ToBytes(JsonConvert.SerializeObject(oLoginData))
            Dim oRequest As HttpWebRequest = GetRequest("/login", oBytes)

            Using oStream = oRequest.GetRequestStream()
                oStream.Write(oBytes, 0, oBytes.Length)
            End Using

            Return oRequest.GetResponse()
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Function Logout() As HttpWebResponse
        Try
            Dim oLogoutData As New LogoutData() With {.email = _userEmail}
            Dim oBytes As Byte() = ToBytes(JsonConvert.SerializeObject(oLogoutData))
            Dim oRequest As HttpWebRequest = GetRequest("/logout", oBytes)

            Using stream = oRequest.GetRequestStream()
                stream.Write(oBytes, 0, oBytes.Length)
            End Using

            Return oRequest.GetResponse()
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Public Function GetData(Query As String, OperationName As String) As HttpWebResponse
        Try
            Dim oQueryData As New QueryData() With {
                .operationName = OperationName,
                .query = Query,
                .variables = New Object
            }
            Dim oJson = JsonConvert.SerializeObject(oQueryData)
            Dim oBytes = ToBytes(oJson)
            Dim oRequest = GetRequest("/graphql", oBytes)

            Using stream = oRequest.GetRequestStream()
                stream.Write(oBytes, 0, oBytes.Length)
            End Using

            Return oRequest.GetResponse()
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Private Function GetRequest(Url As String, PostData As Byte()) As HttpWebRequest
        Try
            Dim oRequest As HttpWebRequest = WebRequest.Create($"{_baseUrl}{Url}")
            oRequest.Method = "POST"
            oRequest.ContentType = "application/json"
            oRequest.ContentLength = PostData.Length
            oRequest.ClientCertificates.Add(_certificate)
            oRequest.CookieContainer = GetCookies()

            oRequest.Proxy = Nothing

            If Proxy Is Nothing Then
                oRequest.Proxy = Nothing
            Else
                oRequest.Proxy = Proxy
                oRequest.Credentials = Credentials
            End If

            Return oRequest
        Catch ex As Exception
            _logger.Error(ex)
            Throw ex
        End Try
    End Function

    Private Function GetCookies() As CookieContainer
        If _cookieJar Is Nothing Then
            _cookieJar = New CookieContainer(300, 20, 8192)
        End If

        Return _cookieJar
    End Function

    Private Function ToBytes(Str As String) As Byte()
        Return _Encoding.GetBytes(Str)
    End Function
End Class