Imports System.Net
Imports System.Net.Http
Imports System.Security.Principal
Imports System.Threading
Imports System.Web.Http.Controllers
Imports System.Web.Http.Description
Imports System.Web.Http.Filters
Imports Microsoft.AspNetCore.Authorization
Imports Swashbuckle.Swagger

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 isValid = userName = "test" AndAlso password = "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
End Class