Imports System.Net
Imports System.Net.Http
Imports System.Security.Principal
Imports System.Threading
Imports System.Web.Http.Controllers
Imports System.Web.Http.Filters
Imports VERAG_PROG_ALLGEMEIN




Public Class BasicAuthenticationAttribute
    Inherits AuthorizationFilterAttribute

    Public Overrides Sub OnAuthorization(ByVal actionContext As HttpActionContext)
        Dim authHeader = actionContext.Request.Headers.Authorization

        If authHeader IsNot Nothing Then
            Dim authenticationToken = actionContext.Request.Headers.Authorization.Parameter
            Dim decodedAuthenticationToken = Encoding.UTF8.GetString(Convert.FromBase64String(authenticationToken))
            Dim usernamePasswordArray = decodedAuthenticationToken.Split(":"c)
            Dim userName = usernamePasswordArray(0)
            Dim password = usernamePasswordArray(1)
            'Dim hashedPW = BCrypt.Net.BCrypt.HashPassword(password)



            Dim isValid = getCredentials(userName, password)

            If isValid Then
                Dim principal = New GenericPrincipal(New GenericIdentity(userName), Nothing)
                Thread.CurrentPrincipal = principal
                'actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.OK, "User " & userName & " successfully authenticated")
                Return
            End If
        End If

        HandleUnathorized(actionContext)
    End Sub

    Private Shared Sub HandleUnathorized(ByVal actionContext As HttpActionContext)
        actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized)
        actionContext.Response.Headers.Add("WWW-Authenticate", "Basic Scheme='Data' location = 'http://localhost:")
    End Sub

    Private Shared Function getCredentials(user As String, password As String) As Boolean

        Dim SQL As New VERAG_PROG_ALLGEMEIN.SQL
        Dim authenticated As Boolean = False

        Dim hashedPassword = SQL.DLookup("hashedPassword", "tblRESTAuthentication", "username='" & user & "' AND type = 'REST'", "ADMIN", "")
        If hashedPassword <> "" Then
            authenticated = BCrypt.Net.BCrypt.Verify(password, hashedPassword)
        End If

        Return authenticated

    End Function
End Class