data_dir <- file.path("..", "testdata")
tempfile_nc <- function() {
  tempfile_helper("fldcovar_")
}

########## output ncdf version 3 ##########
file_in_1 <- file.path(data_dir, "ex_fld_cor_covar_1.nc")
file_in_2 <- file.path(data_dir, "ex_fld_cor_covar_2.nc")
file_out <- tempfile_nc()
fldcovar("SIS", file_in_1, "SIS", file_in_2, file_out)
file <- nc_open(file_out)

test_that("data is correct", {
  actual <- ncvar_get(file)
  
  expected_data <- c(-75.73198, -23.160637, 28.825085)
  expected <- array(expected_data, dim = c(1, 1, 3))
  
  expect_equivalent(actual, expected)
})

test_that("attributes are correct", {
  actual <- ncatt_get(file, "lon", "units")$value
  expect_equal(actual, "degrees_east")
  
  actual <- ncatt_get(file, "lon", "long_name")$value
  expect_equal(actual, "longitude")
  
  actual <- ncatt_get(file, "lon", "standard_name")$value
  expect_equal(actual, "longitude")
  
  actual <- ncatt_get(file, "lon", "axis")$value
  expect_equal(actual, "X")
  
  actual <- ncatt_get(file, "lat", "units")$value
  expect_equal(actual, "degrees_north")
  
  actual <- ncatt_get(file, "lat", "long_name")$value
  expect_equal(actual, "latitude")
  
  actual <- ncatt_get(file, "lat", "standard_name")$value
  expect_equal(actual, "latitude")
  
  actual <- ncatt_get(file, "lat", "axis")$value
  expect_equal(actual, "Y")
  
  actual <- ncatt_get(file, "time", "units")$value
  expect_equal(actual, "hours since 1983-01-01 00:00:00")
  
  actual <- ncatt_get(file, "time", "long_name")$value
  expect_equal(actual, "time")
  
  actual <- ncatt_get(file, "time", "standard_name")$value
  expect_equal(actual, "time")
  
  actual <- ncatt_get(file, "time", "calendar")$value
  expect_equal(actual, "standard")
  
  actual <- ncatt_get(file, "SIS", "standard_name")$value
  expect_equal(actual, "SIS_standard")
  
  actual <- ncatt_get(file, "SIS", "long_name")$value
  expect_equal(actual, "Surface Incoming Shortwave Radiation")
  
  actual <- ncatt_get(file, "SIS", "units")$value
  expect_equal(actual, "W m-2")
  
  actual <- ncatt_get(file, "SIS", "_FillValue")$value
  expect_equal(actual, -999)
  
  actual <- ncatt_get(file, "SIS", "cmsaf_info")$value
  expect_equal(actual, "cmsafops::fldcovar for variable SIS")
  
  global_attr <- ncatt_get(file, 0)
  expect_equal(length(global_attr), 1)
  
  actual <- names(global_attr[1])
  expect_equal(actual, "Info")
  
  actual <- global_attr[[1]]
  expect_equal(actual, "Created with the CM SAF R Toolbox.")
})

nc_close(file)