library(testthat)
library(AutoEDA)
library(ggplot2)

#==========================================================
# PCA object
#==========================================================

pca <- pca_analysis(iris)

#==========================================================
# PCA Biplot
#==========================================================

test_that("pca_biplot returns ggplot", {

  skip_if_not_installed("factoextra")

  p <- pca_biplot(pca)

  expect_s3_class(
    p,
    "ggplot"
  )

})

test_that("pca_biplot returns non-NULL object", {

  skip_if_not_installed("factoextra")

  p <- pca_biplot(pca)

  expect_false(
    is.null(p)
  )

})

test_that("pca_biplot inherits gg class", {

  skip_if_not_installed("factoextra")

  p <- pca_biplot(pca)

  expect_true(
    inherits(p, "gg")
  )

})

#==========================================================
# PCA Variable Plot
#==========================================================

test_that("pca_variable_plot returns ggplot", {

  skip_if_not_installed("factoextra")

  p <- pca_variable_plot(pca)

  expect_s3_class(
    p,
    "ggplot"
  )

})

test_that("pca_variable_plot returns non-NULL object", {

  skip_if_not_installed("factoextra")

  p <- pca_variable_plot(pca)

  expect_false(
    is.null(p)
  )

})

test_that("pca_variable_plot inherits gg class", {

  skip_if_not_installed("factoextra")

  p <- pca_variable_plot(pca)

  expect_true(
    inherits(p, "gg")
  )

})

#==========================================================
# PCA Individual Plot
#==========================================================

test_that("pca_individual_plot returns ggplot", {

  skip_if_not_installed("factoextra")

  p <- pca_individual_plot(pca)

  expect_s3_class(
    p,
    "ggplot"
  )

})

test_that("pca_individual_plot returns non-NULL object", {

  skip_if_not_installed("factoextra")

  p <- pca_individual_plot(pca)

  expect_false(
    is.null(p)
  )

})

test_that("pca_individual_plot inherits gg class", {

  skip_if_not_installed("factoextra")

  p <- pca_individual_plot(pca)

  expect_true(
    inherits(p, "gg")
  )

})

#==========================================================
# Invalid object
#==========================================================

test_that("pca_biplot rejects invalid object", {

  expect_error(

    pca_biplot(iris),

    "'pca' must be a PCAResult object."

  )

})

test_that("pca_variable_plot rejects invalid object", {

  expect_error(

    pca_variable_plot(iris),

    "'pca' must be a PCAResult object."

  )

})

test_that("pca_individual_plot rejects invalid object", {

  expect_error(

    pca_individual_plot(iris),

    "'pca' must be a PCAResult object."

  )

})

#==========================================================
# NULL
#==========================================================

test_that("pca_biplot rejects NULL", {

  expect_error(
    pca_biplot(NULL)
  )

})

test_that("pca_variable_plot rejects NULL", {

  expect_error(
    pca_variable_plot(NULL)
  )

})

test_that("pca_individual_plot rejects NULL", {

  expect_error(
    pca_individual_plot(NULL)
  )

})

#==========================================================
# Corrupted PCAResult
#==========================================================

test_that("pca_biplot rejects incomplete PCAResult", {

  skip_if_not_installed("factoextra")

  bad <- structure(
    list(),
    class = "PCAResult"
  )

  expect_error(
    pca_biplot(bad)
  )

})

test_that("pca_variable_plot rejects incomplete PCAResult", {

  skip_if_not_installed("factoextra")

  bad <- structure(
    list(),
    class = "PCAResult"
  )

  expect_error(
    pca_variable_plot(bad)
  )

})

test_that("pca_individual_plot rejects incomplete PCAResult", {

  skip_if_not_installed("factoextra")

  bad <- structure(
    list(),
    class = "PCAResult"
  )

  expect_error(
    pca_individual_plot(bad)
  )

})