test_that("recommendations are generated", {
  r <- vb_recommend(iris)
  expect_true(nrow(r) > 0)
  expect_true(all(c("priority", "plot", "x", "y", "reason") %in% names(r)))
})

test_that("autoviz object prints", {
  av <- autoviz(iris)
  expect_s3_class(av, "autoviz")
})
test_that("vb_recommend handles categorical variables", {
  dat <- data.frame(
    species = c("dog", "cat", "dog", "cat"),
    stringsAsFactors = FALSE
  )
  
  rec <- vb_recommend(dat)
  
  expect_true(any(rec$plot == "bar"))
  expect_true(any(rec$x == "species"))
})


test_that("vb_recommend recommends line plots for date and numeric variables", {
  dat <- data.frame(
    date = as.Date("2026-01-01") + 0:3,
    weight = c(10, 11, 12, 13)
  )
  
  rec <- vb_recommend(dat)
  
  expect_true(any(rec$plot == "line"))
  expect_true(any(rec$x == "date"))
  expect_true(any(rec$y == "weight"))
})


test_that("vb_recommend recommends scatter plots for numeric relationships", {
  dat <- data.frame(
    x = c(1, 2, 3, 4),
    y = c(2, 4, 6, 8)
  )
  
  rec <- vb_recommend(dat)
  
  expect_true(any(rec$plot == "scatter"))
  expect_true(any(rec$x == "x"))
  expect_true(any(rec$y == "y"))
})


test_that("vb_recommend handles categorical outcome with numeric predictor", {
  dat <- data.frame(
    outcome = factor(c("yes", "no", "yes", "no")),
    age = c(20, 30, 25, 35)
  )
  
  rec <- vb_recommend(dat, outcome = "outcome")
  
  expect_true(any(rec$plot == "boxplot"))
  expect_true(any(
    rec$x == "age" &
      rec$y == "outcome"
  ))
})


test_that("vb_recommend handles numeric outcome with categorical predictor", {
  dat <- data.frame(
    outcome = c(10, 20, 15, 25),
    group = factor(c("A", "B", "A", "B"))
  )
  
  rec <- vb_recommend(dat, outcome = "outcome")
  
  expect_true(any(rec$plot == "boxplot"))
  expect_true(any(
    rec$x == "outcome" &
      rec$y == "group"
  ))
})


test_that("vb_recommend returns table when no standard relationship is detected", {
  dat <- data.frame(
    value = c(1, 2, 3, 4)
  )
  
  rec <- vb_recommend(dat)
  
  expect_equal(nrow(rec), 1)
  expect_equal(rec$plot, "table")
  expect_equal(rec$reason, "No standard plot relationship detected.")
})


test_that("vb_recommend validates outcome and time variables", {
  dat <- data.frame(
    x = c(1, 2, 3),
    y = c(4, 5, 6)
  )
  
  expect_error(
    vb_recommend(dat, outcome = "missing"),
    "outcome.*not a column"
  )
  
  expect_error(
    vb_recommend(dat, time = "missing"),
    "time.*not a column"
  )
})


test_that("vb_recommend respects max_pairs", {
  dat <- data.frame(
    a = 1:5,
    b = 6:10,
    c = 11:15,
    d = 16:20
  )
  
  rec <- vb_recommend(dat, max_pairs = 1)
  
  scatter_rec <- rec[rec$plot == "scatter", ]
  
  expect_lte(nrow(scatter_rec), 1)
})