library(testthat)
library(AutoEDA)

#==========================================================
# pair_plot()
#==========================================================

test_that("pair_plot returns ggmatrix", {

  skip_if_not_installed("GGally")

  p <- pair_plot(iris)

  expect_s3_class(
    p,
    "ggmatrix"
  )

})

test_that("pair_plot works with numeric-only data", {

  skip_if_not_installed("GGally")

  expect_no_error(
    pair_plot(iris[, 1:4])
  )

})

test_that("pair_plot works with tibble", {

  skip_if_not_installed("GGally")
  skip_if_not_installed("tibble")

  dat <- tibble::as_tibble(iris)

  expect_no_error(
    pair_plot(dat)
  )

})

test_that("pair_plot returns ggmatrix for numeric tibble", {

  skip_if_not_installed("GGally")
  skip_if_not_installed("tibble")

  dat <- tibble::as_tibble(iris[, 1:4])

  p <- pair_plot(dat)

  expect_s3_class(
    p,
    "ggmatrix"
  )

})

#==========================================================
# Missing values
#==========================================================

test_that("pair_plot rejects missing values", {

  skip_if_not_installed("GGally")

  dat <- iris
  dat$Sepal.Length[1:10] <- NA

  expect_error(
    pair_plot(dat),
    "Missing values"
  )

})

#==========================================================
# Invalid input
#==========================================================

test_that("pair_plot rejects non-data.frame", {

  expect_error(
    pair_plot(1:10)
  )

})

test_that("pair_plot rejects NULL", {

  expect_error(
    pair_plot(NULL)
  )

})

test_that("pair_plot rejects empty data.frame", {

  expect_error(
    pair_plot(data.frame())
  )

})

test_that("pair_plot rejects one numeric variable", {

  expect_error(
    pair_plot(
      data.frame(
        x = 1:10
      )
    )
  )

})

test_that("pair_plot rejects non-numeric data", {

  expect_error(
    pair_plot(
      data.frame(
        A = letters[1:10],
        B = LETTERS[1:10]
      )
    )
  )

})

test_that("pair_plot rejects character vector", {

  expect_error(
    pair_plot(letters)
  )

})

test_that("pair_plot rejects list", {

  expect_error(
    pair_plot(
      list(
        x = 1:10,
        y = 11:20
      )
    )
  )

})

test_that("pair_plot rejects mixed numeric and character data", {

  expect_error(
    pair_plot(
      data.frame(
        x = 1:10,
        y = letters[1:10]
      )
    )
  )

})

test_that("pair_plot rejects factor-only data", {

  expect_error(
    pair_plot(
      data.frame(
        A = factor(letters[1:10]),
        B = factor(LETTERS[1:10])
      )
    )
  )

})