test_that("date_time.integer", {
  expect_identical(
    dtt_date_time(integer(0)), as.POSIXct("1970-01-01", tz = "UTC")[-1]
  )
  expect_identical(dtt_date_time(NA_integer_), NA_POSIXct_)
  expect_identical(as.integer(as.POSIXct("1970-01-01", tz = "UTC")), 0L)
  expect_identical(dtt_date_time(0L), as.POSIXct("1970-01-01", tz = "UTC"))
  expect_identical(
    dtt_date_time(-1L), as.POSIXct("1969-12-31 23:59:59", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(0L, tz = "Etc/GMT+8"),
    as.POSIXct("1969-12-31 16:00:00", tz = "Etc/GMT+8")
  )

  expect_identical(
    dtt_date_time(2L), as.POSIXct("1970-01-01 00:00:02", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(-2L), as.POSIXct("1969-12-31 23:59:58", tz = "UTC")
  )

  expect_identical(
    dtt_date_time(c(2L, NA)),
    c(as.POSIXct("1970-01-01 00:00:02", tz = "UTC"), NA_POSIXct_)
  )
})

test_that("date_time.double", {
  expect_identical(
    dtt_date_time(double(0)), as.POSIXct("1970-01-01", tz = "UTC")[-1]
  )
  expect_identical(dtt_date_time(NA_real_), NA_POSIXct_)
  expect_identical(as.double(as.POSIXct("1970-01-01", tz = "UTC")), 0)
  expect_identical(dtt_date_time(0), as.POSIXct("1970-01-01", tz = "UTC"))
  expect_identical(
    dtt_date_time(-1),
    as.POSIXct("1969-12-31 23:59:59", tz = "UTC")
  )
  expect_identical(dtt_date_time(0.99), as.POSIXct("1970-01-01", tz = "UTC"))
  expect_identical(
    dtt_date_time(-0.001),
    as.POSIXct("1969-12-31 23:59:59", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(0, tz = "Etc/GMT+8"),
    as.POSIXct("1969-12-31 16:00:00", tz = "Etc/GMT+8")
  )
  expect_identical(
    dtt_date_time(2),
    as.POSIXct("1970-01-01 00:00:02", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(-2),
    as.POSIXct("1969-12-31 23:59:58", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(c(2, NA)),
    c(as.POSIXct("1970-01-01 00:00:02", tz = "UTC"), NA_POSIXct_)
  )
  expect_identical(
    dtt_date(c(1, 2)),
    as.Date(c("1970-01-02", "1970-01-03"))
  )
})

test_that("date_time.character", {
  expect_identical(
    dtt_date_time(character(0)),
    as.POSIXct("1970-01-01", tz = "UTC")[-1]
  )
  expect_identical(dtt_date_time(NA_character_), NA_POSIXct_)
  expect_identical(
    dtt_date_time("1970-01-04"),
    as.POSIXct("1970-01-04", tz = "UTC")
  )
  expect_identical(
    dtt_date_time("1970-01-04", tz = "Etc/GMT+8"),
    as.POSIXct("1970-01-04", tz = "Etc/GMT+8")
  )
  expect_identical(
    dtt_date_time("1970-01-04 11:12:13"),
    as.POSIXct("1970-01-04 11:12:13", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(c("1970-01-04", NA)),
    c(as.POSIXct("1970-01-04", tz = "UTC"), NA)
  )
})

test_that("date_time.Date", {
  expect_identical(
    dtt_date_time(Sys.Date()[-1]),
    as.POSIXct("1970-01-01", tz = "UTC")[-1]
  )
  expect_identical(dtt_date_time(NA_Date_), NA_POSIXct_)
  expect_identical(
    dtt_date_time(as.Date("2000-01-01")),
    as.POSIXct("2000-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(as.Date("2000-01-01"), time = hms::as_hms("01:02:03")),
    as.POSIXct("2000-01-01 01:02:03", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(
      as.Date("2000-01-01"),
      time = hms::as_hms("01:02:03"),
      tz = "Etc/GMT+8"
    ),
    as.POSIXct("2000-01-01 01:02:03", tz = "Etc/GMT+8")
  )
  expect_identical(
    dtt_date_time(as.Date("1970-01-04") + 0.999),
    as.POSIXct("1970-01-04", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(as.Date("1970-01-04") - 0.001),
    as.POSIXct("1970-01-03", tz = "UTC")
  )
})

test_that("date_time.POSIXct", {
  expect_identical(
    dtt_date_time(Sys.time()[-1]),
    as.POSIXct("1970-01-01", tz = Sys.timezone())[-1]
  )
  expect_identical(dtt_date_time(NA_POSIXct_), NA_POSIXct_)
  expect_identical(
    dtt_date_time(as.POSIXct("1970-01-01", tz = "UTC")),
    as.POSIXct("1970-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(as.POSIXct("1970-01-01", tz = "UTC") + 0.999),
    as.POSIXct("1970-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(as.POSIXct("1970-01-01", tz = "UTC") - 1),
    as.POSIXct("1969-12-31 23:59:59", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(as.POSIXct("1970-01-01", tz = "UTC"), tz = "Etc/GMT+8"),
    as.POSIXct("1969-12-31 16:00:0", tz = "Etc/GMT+8")
  )
  expect_identical(
    dtt_date_time(
      c(as.POSIXct("1970-01-01", tz = "UTC"), NA_POSIXct_),
      tz = "Etc/GMT+8"
    ),
    c(as.POSIXct("1969-12-31 16:00:0", tz = "Etc/GMT+8"), NA_POSIXct_)
  )
})

test_that("date_time.hms", {
  expect_identical(
    dtt_date_time(hms::as_hms(3L)[-1]),
    as.POSIXct("1970-01-01", tz = "UTC")[-1]
  )
  expect_identical(dtt_date_time(NA_hms_), NA_POSIXct_)

  expect_identical(
    dtt_date_time(hms::as_hms(0L)),
    as.POSIXct("1970-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(3L)),
    as.POSIXct("1970-01-01 00:00:03", tz = "UTC")
  )

  expect_identical(
    dtt_date_time(hms::as_hms(dtt_units_per_unit())),
    as.POSIXct("1970-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(-1L)),
    as.POSIXct("1970-01-01 23:59:59", tz = "UTC")
  )

  expect_identical(
    dtt_date_time(hms::as_hms(dtt_units_per_unit()), tz = "Etc/GMT+8"),
    as.POSIXct("1970-01-01", tz = "Etc/GMT+8")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(-1L), tz = "Etc/GMT+8"),
    as.POSIXct("1970-01-01 23:59:59", tz = "Etc/GMT+8")
  )

  expect_identical(
    dtt_date_time(hms::as_hms(-dtt_units_per_unit())),
    as.POSIXct("1970-01-01", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(-dtt_units_per_unit() - 1)),
    as.POSIXct("1970-01-01 23:59:59", tz = "UTC")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(-1:0)),
    as.POSIXct(c("1970-01-01 23:59:59", "1970-01-01 00:00:00"), tz = "UTC")
  )
  expect_identical(
    dtt_date_time(hms::as_hms(c(-1L, NA))),
    as.POSIXct(c("1970-01-01 23:59:59", NA), tz = "UTC")
  )
})