test_that("GKIndex produces the right answer for CES_sigma_2", {

  # inverse method of solving
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 12,
                       solveMethod = "inverse"),
               as.matrix(c(1, 0.87763982, 1.14963977, 1.20948388,
                           0.97735333, 1.30228207, 1.23643987,
                           1.00131376, 1.20675381, 0.98419301,
                           1.23476104, 1.23245315)))

  # iterative method of solving
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 12,
                       solveMethod = "iterative"),
               as.matrix(c(1, 0.87763982, 1.14963977, 1.20948388,
                           0.97735333, 1.30228207, 1.23643987,
                           1.00131376, 1.20675381, 0.98419301,
                           1.23476104, 1.23245315)))

})

test_that("GKIndex produces the right answer for different splices", {

  # mean
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 11,
                       splice = "mean"),
               as.matrix(c(1, 0.880516797, 1.146776165, 1.204788832,
                           0.970884329, 1.294436941, 1.228859847,
                           1.000095564, 1.198013216, 0.975391622,
                           1.223185405, 1.230446268)))

  # movement
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 11,
                       splice = "movement"),
               as.matrix(c(1, 0.880516797, 1.146776165, 1.204788832,
                           0.970884329, 1.294436941, 1.228859847,
                           1.000095564, 1.198013216, 0.975391622,
                           1.223185405, 1.223542862)))

  # window
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 11,
                       splice = "window"),
               as.matrix(c(1, 0.880516797, 1.146776165, 1.204788832,
                           0.970884329, 1.294436941, 1.228859847,
                           1.000095564, 1.198013216, 0.975391622,
                           1.223185405, 1.243101)))

  # half
  expect_equal(GKIndex(CES_sigma_2,
                       pvar = "prices",
                       qvar = "quantities",
                       prodID = "prodID",
                       pervar = "time",
                       window = 11,
                       splice = "half"),
               as.matrix(c(1, 0.880516792639476, 1.14677616370861, 1.20478883103346,
                           0.970884329042465, 1.29443693892348, 1.22885984521462, 1.00009556334273,
                           1.19801321479787, 0.975391622972356, 1.22318540412509, 1.23085666351138)))

  # wisp
  expect_equal(GKIndex(CES_sigma_2,
                         pvar = "prices",
                         qvar = "quantities",
                         prodID = "prodID",
                         pervar = "time",
                         window = 11,
                         splice = "wisp"),
               as.matrix(c(1, 0.880516792639476, 1.14677616370861, 1.20478883103346,
                           0.970884329042465, 1.29443693892348, 1.22885984521462, 1.00009556334273,
                           1.19801321479787, 0.975391622972356, 1.22318540412509, 1.24310097571958)))

  # hasp
  expect_equal(GKIndex(CES_sigma_2,
                         pvar = "prices",
                         qvar = "quantities",
                         prodID = "prodID",
                         pervar = "time",
                         window = 11,
                         splice = "hasp"),
               as.matrix(c(1, 0.880516792639476, 1.14677616370861, 1.20478883103346,
                           0.970884329042465, 1.29443693892348, 1.22885984521462, 1.00009556334273,
                           1.19801321479787, 0.975391622972356, 1.22318540412509, 1.23085666351138)))

  # mean_pub
  expect_equal(GKIndex(CES_sigma_2,
                         pvar = "prices",
                         qvar = "quantities",
                         prodID = "prodID",
                         pervar = "time",
                         window = 11,
                         splice = "mean_pub"),
               as.matrix(c(1, 0.880516792639476, 1.14677616370861, 1.20478883103346,
                           0.970884329042465, 1.29443693892348, 1.22885984521462, 1.00009556334273,
                           1.19801321479787, 0.975391622972356, 1.22318540412509, 1.23044626729226)))

})

test_that("The right GKIndex result is given when prices are imputed", {

  df <- CES_sigma_2[-c(2:3),]
  result <- GKIndex(df, pvar = "prices", qvar = "quantities", pervar = "time",
                       prodID = "prodID", imputePrices = "carry", window = 12)

  expect_equal(result, as.matrix(c(1, 0.845456231499799, 1.12667552753356, 1.21307301784934,
                                   0.979935919797748, 1.30823790438779, 1.24195298875981, 1.00350594026418,
                                   1.21305477610043, 0.988593091923226, 1.24335349326667, 1.24219039245365
  )))

})


test_that("Error is thrown for wrong splice method", {

  expect_error(GKIndex(CES_sigma_2,pvar = "prices",qvar = "quantities",
                         pervar = "time", prodID = "prodID",
                         sample = "matched", window = 12, splice = "wrongSplice"),
               "Not a valid splicing method.")

})

test_that("Error is thrown for wrong imputePrices parameter", {

  expect_error(GEKSIndex(CES_sigma_2,pvar = "prices",qvar = "quantities",
                         pervar = "time", prodID = "prodID",
                         sample = "matched", window = 12, splice = "window", imputePrices = "wrongImpute"),
               "Invalid imputePrices argument")

})

test_that("Error is thrown when time/product combinations are not unique", {
  duped <- CES_sigma_2
  # set the time for the second observation on product 1 to period 1
  # which creates a duplicate time/product combination
  duped$time[2] <- 1
  expect_error(GKIndex(duped, pvar="prices", qvar="quantities", pervar="time", prodID = "prodID",
                         window = 9))
})