skip_if_not_installed("gbm")

set.seed(102) # for reproducibility
invisible(capture.output(
  suppressPackageStartupMessages({
    m1 <- gbm::gbm(
      mpg ~ gear + cyl + wt,
      data = mtcars,
      var.monotone = c(0, 0, 0),
      distribution = "gaussian",
      shrinkage = 0.1,
      interaction.depth = 1,
      bag.fraction = 0.5,
      train.fraction = 0.5,
      n.minobsinnode = 1,
      cv.folds = 3,
      keep.data = TRUE,
      verbose = FALSE,
      n.cores = 1
    )
  })
))

test_that("model_info", {
  expect_true(model_info(m1)$is_linear)
  expect_false(model_info(m1)$is_binomial)
})

test_that("find_predictors", {
  expect_identical(find_predictors(m1), list(conditional = c("gear", "cyl", "wt")))
  expect_identical(
    find_predictors(m1, flatten = TRUE),
    c("gear", "cyl", "wt")
  )
  expect_null(find_predictors(m1, effects = "random"))
})

test_that("find_random", {
  expect_null(find_random(m1))
})

test_that("get_random", {
  expect_warning(get_random(m1))
})

test_that("find_response", {
  expect_identical(find_response(m1), "mpg")
})

test_that("get_response", {
  expect_equal(get_response(m1), mtcars$mpg)
})

test_that("get_predictors", {
  expect_equal(colnames(get_predictors(m1)), c("gear", "cyl", "wt"))
})

test_that("link_inverse", {
  expect_equal(link_inverse(m1)(0.2), 0.2, tolerance = 1e-5)
})

test_that("get_data", {
  expect_equal(nrow(get_data(m1)), 32)
  expect_equal(colnames(get_data(m1)), c("mpg", "gear", "cyl", "wt"))
})

test_that("find_formula", {
  expect_length(find_formula(m1), 1)
  expect_equal(
    find_formula(m1),
    list(conditional = as.formula("mpg ~ gear + cyl + wt")),
    ignore_attr = TRUE
  )
})

test_that("find_variables", {
  expect_equal(
    find_variables(m1),
    list(
      response = "mpg",
      conditional = c("gear", "cyl", "wt")
    )
  )
  expect_equal(
    find_variables(m1, flatten = TRUE),
    c("mpg", "gear", "cyl", "wt")
  )
})

test_that("n_obs", {
  expect_equal(n_obs(m1), 32)
})

test_that("linkfun", {
  expect_false(is.null(link_function(m1)))
})

test_that("find_parameters", {
  expect_equal(
    find_parameters(m1),
    list(conditional = c("wt", "cyl", "gear"))
  )
  expect_equal(nrow(get_parameters(m1)), 3)
  expect_equal(get_parameters(m1)$Parameter, c("wt", "cyl", "gear"))
})

test_that("find_terms", {
  expect_equal(
    find_terms(m1),
    list(
      response = "mpg",
      conditional = c("gear", "cyl", "wt")
    )
  )
})

test_that("is_multivariate", {
  expect_false(is_multivariate(m1))
})

test_that("find_algorithm", {
  expect_warning(expect_null(find_algorithm(m1)))
})

test_that("find_statistic", {
  expect_null(find_statistic(m1))
})