skip_if_not_installed("plm")
skip_if_not_installed("feisr")

data(mwp, package = "feisr")
m1 <- feisr::feis(
  lnw ~ marry + enrol + as.factor(yeargr) | exp + I(exp^2),
  data = mwp,
  id = "id",
  robust = TRUE
)

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

m_tmp <- m1
m_tmp$vcov_arg <- "Normal standard errors"
test_that("get_varcov", {
  expect_equal(vcov(m_tmp, scale = TRUE), get_varcov(m1), tolerance = 1e-3)
})

test_that("find_predictors", {
  expect_identical(find_predictors(m1), list(
    conditional = c("marry", "enrol", "yeargr"),
    slopes = "exp"
  ))
  expect_identical(find_predictors(m1, effects = "random"), list(random = "id"))
  expect_identical(
    find_predictors(m1, effects = "all", flatten = TRUE),
    c("marry", "enrol", "yeargr", "exp", "id")
  )
})

test_that("find_random", {
  expect_identical(find_random(m1), list(random = "id"))
})

test_that("get_random", {
  expect_identical(colnames(get_random(m1)), "id")
})

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

test_that("get_response", {
  expect_equal(get_response(m1), mwp$lnw)
})

test_that("get_predictors", {
  expect_equal(
    colnames(get_predictors(m1)),
    c("marry", "enrol", "yeargr", "exp")
  )
})

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)), 3100)
  expect_equal(
    colnames(get_data(m1)),
    c("lnw", "marry", "enrol", "yeargr", "exp", "id")
  )
})

test_that("get_df", {
  expect_equal(
    get_df(m1, type = "residual"),
    df.residual(m1),
    ignore_attr = TRUE
  )
  expect_equal(
    get_df(m1, type = "normal"),
    Inf,
    ignore_attr = TRUE
  )
  expect_equal(
    get_df(m1, type = "wald"),
    2290,
    ignore_attr = TRUE
  )
})

test_that("find_formula", {
  expect_length(find_formula(m1), 3)
  expect_equal(
    find_formula(m1),
    list(
      conditional = as.formula("lnw ~ marry + enrol + as.factor(yeargr)"),
      slopes = as.formula("~exp + I(exp^2)"),
      random = as.formula("~id")
    ),
    ignore_attr = TRUE
  )
})

test_that("find_terms", {
  expect_equal(
    find_terms(m1),
    list(
      response = "lnw",
      conditional = c("marry", "enrol", "as.factor(yeargr)"),
      slopes = c("exp", "I(exp^2)"),
      random = "id"
    )
  )
  expect_equal(
    find_terms(m1, flatten = TRUE),
    c(
      "lnw",
      "marry",
      "enrol",
      "as.factor(yeargr)",
      "exp",
      "I(exp^2)",
      "id"
    )
  )
})

test_that("find_variables", {
  expect_equal(
    find_variables(m1),
    list(
      response = "lnw",
      conditional = c("marry", "enrol", "yeargr"),
      slopes = "exp",
      random = "id"
    )
  )
  expect_equal(
    find_variables(m1, flatten = TRUE),
    c("lnw", "marry", "enrol", "yeargr", "exp", "id")
  )
})

test_that("n_obs", {
  expect_equal(n_obs(m1), 3100)
})

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

test_that("find_parameters", {
  expect_equal(
    find_parameters(m1),
    list(
      conditional = c(
        "marry",
        "enrol",
        "as.factor(yeargr)2",
        "as.factor(yeargr)3",
        "as.factor(yeargr)4",
        "as.factor(yeargr)5"
      )
    )
  )
  expect_equal(nrow(get_parameters(m1)), 6)
  expect_equal(
    get_parameters(m1)$Parameter,
    c(
      "marry",
      "enrol",
      "as.factor(yeargr)2",
      "as.factor(yeargr)3",
      "as.factor(yeargr)4",
      "as.factor(yeargr)5"
    )
  )
})

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

test_that("find_statistic", {
  expect_identical(find_statistic(m1), "t-statistic")
})