test_that("br_show_nomogram handles interaction scenarios correctly", {
  skip_on_cran()

  # Test 1: Basic nomogram with factor variables (user's original scenario)
  mtcars$gear <- factor(mtcars$gear)
  mds <- bregr::br_pipeline(mtcars,
    y = "mpg",
    x = c("hp", "gear"),
    x2 = "vs",
    method = "gaussian"
  )

  # Both models should create nomograms without error
  expect_s3_class(
    {
      p1 <- bregr::br_show_nomogram(mds, idx = 1, fun_at = c(15, 20, 25, 30))
      p1
    },
    "ggplot"
  )

  expect_s3_class(
    {
      p2 <- bregr::br_show_nomogram(mds, idx = 2, fun_at = c(15, 20, 25, 30))
      p2
    },
    "ggplot"
  )

  # Test 2: Cox nomogram with factor variables
  lung <- survival::lung |> dplyr::filter(ph.ecog != 3, !is.na(ph.ecog))
  lung$ph.ecog <- factor(lung$ph.ecog)
  lung$sex <- factor(lung$sex)

  mds_cox <- bregr::br_pipeline(lung,
    y = c("time", "status"),
    x = c("age", "ph.ecog"),
    x2 = "sex",
    method = "coxph"
  )

  expect_s3_class(
    {
      p3 <- bregr::br_show_nomogram(mds_cox, idx = 1)
      p3
    },
    "ggplot"
  )

  expect_s3_class(
    {
      p4 <- bregr::br_show_nomogram(mds_cox, idx = 2)
      p4
    },
    "ggplot"
  )

  # Test 3: Nomogram with character factor levels
  mtcars$cyl_factor <- factor(mtcars$cyl, labels = c("Four", "Six", "Eight"))
  mds_char <- bregr::br_pipeline(mtcars,
    y = "mpg",
    x = c("hp", "cyl_factor"),
    x2 = "vs",
    method = "gaussian"
  )

  expect_s3_class(
    {
      p5 <- bregr::br_show_nomogram(mds_char, idx = 1, fun_at = c(15, 20, 25))
      p5
    },
    "ggplot"
  )

  expect_s3_class(
    {
      p6 <- bregr::br_show_nomogram(mds_char, idx = 2, fun_at = c(15, 20, 25))
      p6
    },
    "ggplot"
  )
})