// testRemoteState is used to make a test HTTP server to
// return a given state file
func testRemoteState(t *testing.T, s *terraform.State, c int) (*terraform.RemoteState, *httptest.Server) {
	var b64md5 string
	buf := bytes.NewBuffer(nil)

	cb := func(resp http.ResponseWriter, req *http.Request) {
		if req.Method == "PUT" {
			resp.WriteHeader(c)
			return
		}
		if s == nil {
			resp.WriteHeader(404)
			return
		}

		resp.Header().Set("Content-MD5", b64md5)
		resp.Write(buf.Bytes())
	}

	srv := httptest.NewServer(http.HandlerFunc(cb))
	remote := &terraform.RemoteState{
		Type:   "http",
		Config: map[string]string{"address": srv.URL},
	}

	if s != nil {
		// Set the remote data
		s.Remote = remote

		enc := json.NewEncoder(buf)
		if err := enc.Encode(s); err != nil {
			t.Fatalf("err: %v", err)
		}
		md5 := md5.Sum(buf.Bytes())
		b64md5 = base64.StdEncoding.EncodeToString(md5[:16])
	}

	return remote, srv
}