test_that("yearquarter constructor and coercion to date works", {
    dates <- seq.Date(from = as.Date("1970-01-01"), length.out = 4, by = "3 months")
    storage.mode(dates) <- "double" # needed for R <= 4.1.3
    yq4 <- new_yearquarter(0:3)

    expect_identical(as.Date(yq4), dates)

    # formatting --------------------------------------------------------------
    expect_identical(format(yq4), c("1970-Q1", "1970-Q2", "1970-Q3", "1970-Q4"))
    expect_identical(format(new_yearquarter()), character())

    dat <- as.Date("1900-01-01") + seq.int(from = 0L, to = 200L * 365, by = 180L)
    expected <- as_yearquarter(dat)
    tmp <- as.character(dat)
    years <- as.integer(substr(tmp, 1L, 4L))
    months <- as.integer(substr(tmp, 6L, 7L))
    expect_identical(yearquarter(years, ((months - 1L) %/% 3L) + 1L), expected)
})

test_that("yearquarter, pre-epoch dates work", {
    dates <- seq.Date(from = as.Date("1900-01-01"), length.out = 4, by = "3 months")
    storage.mode(dates) <- "double" # needed for R <= 4.1.3
    dates2 <- seq.Date(from = as.Date("1899-01-01"), length.out = 4, by = "3 month")
    storage.mode(dates2) <- "double" # needed for R <= 4.1.3
    expect_identical(as.Date(as_yearquarter(dates)), dates)
    expect_identical(as.Date(as_yearquarter(dates) - 4), dates2)
})


test_that("yearquarter, POSIXlt coercion works", {
    nz <- as.POSIXlt("2021-01-04 02:00:00", tz = "NZ")
    utc <- as.POSIXlt("2021-01-01 00:00:00", tz = "UTC")
    result <- as.POSIXlt(as_yearquarter(nz))

    expect_identical(result, utc)

    dat <- "2021-01-01"
    pos <- as.POSIXlt("2021-02-04", tz = "UTC")
    res1 <- as_yearquarter(pos)

    expect_identical(as.Date(res1), as.Date(dat))

    dat <- "2021-01-01"
    res <- as.POSIXlt(as_yearquarter(dat))
    expect_s3_class(res, "POSIXlt")
    expect_identical(julian(res), julian(as.POSIXlt(dat, tz = "UTC")))
    expect_error(
        as.POSIXlt(as_yearquarter(dat), tz = "GMT"),
        "<grates_yearquarter> objects can only be converted to UTC. If other timezones are required, first convert to <Date> and then proceed as desired.",
        fixed = TRUE
    )
})

test_that("yearquarter, POSIXct coercion works", {
    nz <- as.POSIXct(as.POSIXlt("2021-01-04", tz = "NZ"))
    dat <- as_yearquarter(nz)
    result <- as.POSIXct(dat)
    expect_identical(result, as.POSIXct(as.POSIXlt("2021-01-01", tz = "UTC")))

    pos <- as.POSIXct(as.POSIXlt("2021-03-04", tz = "UTC"))
    res1 <- as_yearquarter(pos)
    expect_identical(as.Date(res1), as.Date("2021-01-01"))

    dat <- "2021-01-01"
    res <- as.POSIXct(as_yearquarter(dat))
    expect_identical(res, as.POSIXct(as.POSIXlt(dat), tz = "UTC"))
    expect_error(
        as.POSIXct(as_yearquarter(dat), tz = "GMT"),
        "<grates_yearquarter> objects can only be converted to UTC. If other timezones are required, first convert to <Date> and then proceed as desired.",
        fixed = TRUE
    )
})

test_that("yearquarter, character coercion works", {
    dat <- "2021-01-04"
    res <- as_yearquarter(dat)
    expect_identical(as.Date(res), as.Date("2021-01-01"))

    dat <- as.factor("2021-02-04")
    res <- as_yearquarter(dat)
    expect_identical(as.Date(res), as.Date("2021-01-01"))

    dat <- "2020-12-28"
    res <- as.character(as_yearquarter(dat))
    expect_identical(res, "2020-Q4")
})

test_that("as_yearquarter, misc errors and warnings", {
    expect_error(
        as_yearquarter(TRUE),
        "Not implemented for class [logical].",
        fixed = TRUE
    )
    expect_error(as_yearquarter("bob"))
})


test_that("yearquarter, as.list works", {
    dat <- as_yearquarter(c("2020-12-28", "2021-01-04"))
    res <- list(as_yearquarter("2020-12-28"), as_yearquarter("2021-01-04"))
    expect_identical(res, as.list(dat))
})

test_that("yearquarter, accessors", {
    dat <- as_yearquarter(as.Date("2020-12-28"))
    expect_identical(get_year(dat), 2020L)
})

test_that("yearquarter, is_yearquarter works", {
    dat <- as_yearquarter(Sys.Date())
    expect_true(is_yearquarter(dat))
    expect_false(is_yearquarter("bob"))
})

test_that("yearquarter, subsetting works", {
    x <- as.Date("2020-03-01")
    dat <- as_yearquarter(x) + 0:1
    dat <- setNames(dat, c("a", "b"))
    expect_identical(dat[1], c(a=as_yearquarter(x)))
    expect_identical(dat[[2]], as_yearquarter(x + 33))
    dat[1] <- as_yearquarter(x+33)
    expect_identical(dat[1], c(a=as_yearquarter(x + 33)))
    dat[[2]] <- dat[[1]]
    expect_identical(dat[[2]], dat[[1]])
    expect_error(
        dat[1] <- "bob",
        "Can only assign <grates_yearquarter> objects in to an <grates_yearquarter> object.",
        fixed = TRUE
    )
})

test_that("yearquarter, combine works", {
    x <- Sys.Date()
    dat <- as_yearquarter(x)
    expect_identical(c(dat, dat), as_yearquarter(c(x, x)))
    expect_error(
        c(dat, "bob"),
        "Unable to combine <grates_yearquarter> objects with other classes.",
        fixed = TRUE
    )
})

test_that("yearquarter operators and math work", {
    # comparison operators ----------------------------------------------------
    x <- Sys.Date()
    dat1 <- as_yearquarter(x)
    dat2 <- as_yearquarter(x)
    expect_true(dat1 == dat2)
    expect_false(dat1 != dat2)
    expect_true(dat1 == dat1)
    expect_true(dat1 <= dat1 + 1)
    expect_true(dat1 >= dat1 - 1)
    expect_true(dat1 < dat1 + 1)
    expect_true(dat1 > dat1 - 1)
    expect_true(dat1 != dat1 + 1)
    expect_error(
        dat1 == TRUE,
        "Can only compare <grates_yearquarter> objects with <grates_yearquarter> objects.",
        fixed = TRUE
    )

    # addition ----------------------------------------------------------------
    x <- as.Date("2021-01-05")
    y <- as.Date("2021-01-04")
    dat1 <- as_yearquarter(x)
    dat2 <- dat1 + 0:1
    expect_identical(as.Date(dat2), as.Date(c("2021-01-01", "2021-04-01")))
    expect_identical(dat2, 0:1 + dat1)
    expect_identical(+dat1, dat1)
    expect_error(
        dat1 + 1.5,
        "Can only add integers to <grates_yearquarter> objects.",
        fixed = TRUE
    )
    expect_error(
        dat1 + dat1,
        "Cannot add <grates_yearquarter> objects to each other.",
        fixed = TRUE
    )

    # subtraction -------------------------------------------------------------
    x <- as.Date("2021-01-05")
    y <- as.Date("2021-01-04")
    dat1 <- as_yearquarter(x)
    dat2 <- dat1 - 0:1
    expect_identical(as.Date(dat2), as.Date(c("2021-01-01", "2020-10-01")))
    expect_identical(as.integer(dat2 - dat1), c(0L, -1L))
    expect_error(
        1 - dat1,
        "Can only subtract from a <grates_yearquarter> object, not vice-versa.",
        fixed = TRUE
    )
    expect_error(
        -dat1,
        "Cannot negate a <grates_yearquarter> object.",
        fixed = TRUE
    )
    expect_error(
        dat1 - 1.5,
        "Can only subtract whole numbers and other <grates_yearquarter> objects from <grates_yearquarter> objects.",
        fixed = TRUE
    )

    # Other operations error
    x <- as_yearquarter(as.Date("2021-01-05"))
    expect_error(dat * 3)
    expect_error(dat / 3)
    expect_error(dat ^ 3)
    expect_error(dat %% 3)
    expect_error(dat %/% 3)
    expect_error(dat & 3)
    expect_error(dat | 3)
    expect_error(!dat)

    # Math
    x <- as_yearquarter(as.Date("2021-01-05"))
    dat <- c(x + 0:1, new_yearquarter(NA_integer_))
    expect_identical(is.nan(dat), c(FALSE, FALSE, FALSE))
    expect_identical(is.finite(dat), c(TRUE, TRUE, FALSE))
    expect_identical(is.infinite(dat), c(FALSE, FALSE, FALSE))
    expect_error(abs(dat))

})

test_that("yearquarter, miscellaneous work", {
    expect_identical(new_yearquarter(-1.5), new_yearquarter(-2L))
    expect_error(new_yearquarter("bob"), "`x` must be integer.", fixed = TRUE)
    expect_error(
        as_yearquarter(NA_character_),
        "Unable to parse any entries of `x` as Dates.",
        fixed = TRUE
    )
    dat <- as.Date("2020-01-20")
    dat <- c(dat, dat - 40L)
    dat <- as_yearquarter(dat)
    expect_identical(rep(dat, 2L), c(dat, dat))
    expect_identical(rep(dat, each = 2L), c(dat[[1]], dat[[1]], dat[[2]], dat[[2]]))
    expect_identical(unique(c(dat, dat)), dat)
    dat <- as_yearquarter(as.Date("1970-01-01"))
    expect_identical(
        seq(dat, dat + 11, by = 2L),
        new_yearquarter(c(0L, 2L, 4L, 6L, 8L, 10L))
    )
    expect_error(
        seq(dat, dat + 11, by = 2.5),
        "`by` must be an integer of length 1.",
        fixed = TRUE
    )
    expect_error(
        seq(dat, as.integer(dat + 11), by = 2.5),
        "`to` must be a <grates_yearquarter> object of length 1.",
        fixed = TRUE
    )
    expect_identical(as.integer(new_yearquarter(100L)), 100L)
    expect_identical(as.double(new_yearquarter(100L)), 100)
    expect_identical(min(c(dat, dat+11)), dat)
    expect_identical(max(c(dat, dat+11)), dat+11)
    expect_identical(range(seq(dat, dat + 12, by = 2L)), c(dat, dat+12))
    expect_error(
        any(dat),
        "`any()` is not supported for <grates_yearquarter> objects.",
        fixed = TRUE
    )

    expect_identical(yearquarter(1L,1L),yearquarter(1.5,1.5))
    expect_error(yearquarter(1L), "Cannot recycle a vector of length 0:", fixed = TRUE)
    expect_error(yearquarter(1:2,1:3), "Can only recycle vectors of length 1:", fixed = TRUE)
    expect_error(yearquarter(year = character()), "`year` must be integer.", fixed = TRUE)
    expect_error(yearquarter(quarter = character()), "`quarter` must be integer.")
    expect_error(yearquarter(1L,0L), "quarters must be integer and between 1 and 4 (inclusive) or NA. Entry 1 is not (it equals 0).", fixed = TRUE)
    expect_error(yearquarter(1L,5L), "quarters must be integer and between 1 and 4 (inclusive) or NA. Entry 1 is not (it equals 5).", fixed = TRUE)
})