skip_if_not_installed("gamm4")
skip_if_not_installed("mgcv")

set.seed(0)
void <- capture.output(dat <- mgcv::gamSim(1, n = 400, scale = 2)) ## simulate 4 term additive truth
dat$fac <- fac <- as.factor(sample(1:20, 400, replace = TRUE))
dat$y <- dat$y + model.matrix(~ fac - 1) %*% rnorm(20) * 0.5

m1 <- gamm4::gamm4(y ~ s(x0) + x1 + s(x2),
  data = dat,
  random = ~ (1 | fac)
)

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

test_that("clean_names", {
  expect_equal(clean_names(m1), c("y", "x0", "x1", "x2", "fac"))
})

test_that("find_predictors", {
  expect_identical(find_predictors(m1), list(conditional = c("x0", "x1", "x2")))
  expect_identical(find_predictors(m1, flatten = TRUE), c("x0", "x1", "x2"))
  expect_identical(find_predictors(m1, effects = "random"), list(random = "fac"))
})

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

test_that("get_response", {
  expect_equal(get_response(m1), unname(dat$y[, 1]))
})

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)), 400)
  expect_equal(
    colnames(get_data(m1)),
    c(
      "y",
      "x1",
      "x0",
      "x2",
      "fac",
      "y.0",
      "Xr",
      "Xr.0",
      "X.(Intercept)",
      "X.x1",
      "X.s(x0)Fx1",
      "X.s(x2)Fx1"
    )
  )
})

test_that("find_formula", {
  expect_length(find_formula(m1), 2)
  expect_equal(
    find_formula(m1),
    list(
      conditional = as.formula("y ~ s(x0) + x1 + s(x2)"),
      random = as.formula("~1 | fac")
    ),
    ignore_attr = TRUE
  )
})

test_that("find_terms", {
  expect_equal(find_terms(m1), list(
    response = "y",
    conditional = c("s(x0)", "x1", "s(x2)"),
    random = "fac"
  ))
  expect_equal(
    find_terms(m1, flatten = TRUE),
    c("y", "s(x0)", "x1", "s(x2)", "fac")
  )
})

test_that("find_variables", {
  expect_equal(find_variables(m1), list(
    response = "y",
    conditional = c("x0", "x1", "x2"),
    random = "fac"
  ))
  expect_equal(find_variables(m1, flatten = TRUE), c("y", "x0", "x1", "x2", "fac"))
})

test_that("n_obs", {
  expect_equal(n_obs(m1), 400)
})

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

test_that("find_parameters", {
  expect_equal(
    find_parameters(m1),
    list(
      conditional = c("(Intercept)", "x1"),
      smooth_terms = c("s(x0)", "s(x2)")
    )
  )
  expect_equal(nrow(get_parameters(m1)), 4)
  expect_equal(
    get_parameters(m1)$Parameter,
    c("(Intercept)", "x1", "s(x0)", "s(x2)")
  )
})

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

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