skip_if_not_installed("ivreg")

data("CigaretteDemand", package = "ivreg")

m1 <- ivreg::ivreg(log(packs) ~ log(rprice) + log(rincome) | salestax + log(rincome),
  data = CigaretteDemand
)

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

test_that("find_predictors", {
  expect_identical(
    find_predictors(m1),
    list(
      conditional = c("rprice", "rincome"),
      instruments = c("salestax", "rincome")
    )
  )
  expect_identical(
    find_predictors(m1, flatten = TRUE),
    c("rprice", "rincome", "salestax")
  )
  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), "packs")
})

test_that("get_response", {
  expect_equal(get_response(m1), CigaretteDemand$packs)
})

test_that("get_predictors", {
  expect_equal(
    colnames(get_predictors(m1)),
    c("rprice", "rincome", "salestax")
  )
})

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)), 48)
  expect_equal(
    colnames(get_data(m1)),
    c("packs", "rprice", "rincome", "salestax")
  )
})

test_that("find_formula", {
  expect_length(find_formula(m1), 2)
  expect_equal(
    find_formula(m1),
    list(
      conditional = as.formula("log(packs) ~ log(rprice) + log(rincome)"),
      instruments = as.formula("~salestax + log(rincome)")
    ),
    ignore_attr = TRUE
  )
})

test_that("find_variables", {
  expect_equal(
    find_variables(m1),
    list(
      response = "packs",
      conditional = c("rprice", "rincome"),
      instruments = c("salestax", "rincome")
    )
  )
  expect_equal(
    find_variables(m1, flatten = TRUE),
    c("packs", "rprice", "rincome", "salestax")
  )
})

test_that("n_obs", {
  expect_equal(n_obs(m1), 48)
})

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

test_that("find_parameters", {
  expect_equal(
    find_parameters(m1),
    list(
      conditional = c("(Intercept)", "log(rprice)", "log(rincome)")
    )
  )
  expect_equal(nrow(get_parameters(m1)), 3)
  expect_equal(
    get_parameters(m1)$Parameter,
    c("(Intercept)", "log(rprice)", "log(rincome)")
  )
})

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

test_that("find_terms", {
  expect_equal(
    find_terms(m1),
    list(
      response = "log(packs)",
      conditional = c("log(rprice)", "log(rincome)"),
      instruments = c("salestax", "log(rincome)")
    )
  )
  expect_equal(nrow(get_parameters(m1)), 3)
  expect_equal(
    get_parameters(m1)$Parameter,
    c("(Intercept)", "log(rprice)", "log(rincome)")
  )
})

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