test_that("basic math ops works", {
  x = as.integer64(1:10)
  y = as.integer64(10:1)

  expect_identical(x + y, as.integer64(rep(11L, 10L)))
  expect_identical(y - x, as.integer64(seq(9L, -9L, by=-2L)))
  expect_identical(x * y, as.integer64(c(10L, 18L, 24L, 28L, 30L, 30L, 28L, 24L, 18L, 10L)))
  # output is double even though it fits in integer [and integer64]
  expect_identical(x[seq(2L, 10L, by=2L)] / 2L, as.double(1:5))
  expect_identical(x^2L, as.integer64((1:10)^2L))
  expect_identical(-x, as.integer64(-(1:10)))

  expect_identical(x %/% 2L, as.integer64(c(0L, 1L, 1L, 2L, 2L, 3L, 3L, 4L, 4L, 5L)))
  expect_identical(x %% 2L, as.integer64(rep_len(c(1L, 0L), 10L)))

  x32 = c(10L, 10L, -10L, -10L, 7L, 10L, -10L)
  y32 = c(3L, -3L, 3L, -3L, -10L, 0L, 0L)
  x64 = as.integer64(x32)
  y64 = as.integer64(y32)
  expect_warning(
    expect_identical(x64 %/% y64, as.integer64(x32 %/% y32)),
    "NAs produced due to division by zero"
  )
  expect_warning(
    expect_identical(x64 %% y64, as.integer64(x32 %% y32)),
    "NAs produced due to division by zero"
  )
  expect_identical(
    suppressWarnings((x64 %/% y64) * y64 + x64 %% y64 == x64),
    c(rep(TRUE, 5L), rep(NA, 2L))
  )

  # regression snuck through, caught by #149
  expect_identical(as.integer64(1L) * 1:5, as.integer64(1:5))
  expect_identical(1:5 * as.integer64(1L), as.integer64(1:5))
})

test_that("empty inputs give empty outputs for ops", {
  x = integer64(1L)
  empty = integer64(0L)

  expect_identical(x + empty, integer64())
  expect_identical(empty + x, integer64())

  expect_identical(x - empty, integer64())
  expect_identical(empty - x, integer64())

  expect_identical(+empty, integer64())
  expect_identical(-empty, integer64())

  expect_identical(x * empty, integer64())
  expect_identical(empty * x, integer64())

  expect_identical(x / empty, double())
  expect_identical(empty / x, double())

  expect_identical(x^empty, integer64())
  expect_identical(empty^x, integer64())

  expect_identical(x %/% empty, integer64())
  expect_identical(empty %/% x, integer64())

  expect_identical(x %% empty, integer64())
  expect_identical(empty %% x, integer64())

  expect_identical(x == empty, logical())
  expect_identical(empty == x, logical())

  expect_identical(x != empty, logical())
  expect_identical(empty != x, logical())

  expect_identical(x >= empty, logical())
  expect_identical(empty >= x, logical())

  expect_identical(x <= empty, logical())
  expect_identical(empty <= x, logical())

  expect_identical(x > empty, logical())
  expect_identical(empty > x, logical())

  expect_identical(x < empty, logical())
  expect_identical(empty < x, logical())

  expect_identical(x & empty, logical())
  expect_identical(empty & x, logical())

  expect_identical(x | empty, logical())
  expect_identical(empty | x, logical())

  expect_identical(xor(x, empty), logical())
  expect_identical(xor(empty, x), logical())
})

test_that("semantics about mixed types for multiplication are respected", {
  int = 5L
  i64 = as.integer64(2L)
  dbl = 3.5

  # default: "old" semantics, to be deprecated
  expect_identical(i64 * dbl, as.integer64(7L))
  expect_identical(dbl * i64, as.integer64(6L))
  expect_identical(i64 * int, as.integer64(10L))
  expect_identical(int * i64, as.integer64(10L))
  expect_identical(i64 * i64, as.integer64(4L))

  withr::with_options(list(integer64_semantics = "new"), {
    expect_identical(i64 * dbl, as.integer64(7L))
    expect_identical(dbl * i64, as.integer64(7L))
    expect_identical(i64 * int, as.integer64(10L))
    expect_identical(int * i64, as.integer64(10L))
    expect_identical(i64 * i64, as.integer64(4L))
  })
})

test_that("semantics about mixed types for division are respected", {
  int = 10L
  i64 = as.integer64(5L)
  dbl = 2.5

  # default: "old" semantics, to be deprecated
  expect_identical(i64 / dbl, 2.0)
  expect_identical(dbl / i64, 0.4)
  expect_identical(i64 / int, 0.5)
  expect_identical(int / i64, 2.0)
  expect_identical(i64 / i64, 1.0)

  withr::with_options(list(integer64_semantics = "new"), {
    expect_identical(i64 / dbl, 2.0)
    expect_identical(dbl / i64, 0.5)
    expect_identical(i64 / int, 0.5)
    expect_identical(int / i64, 2.0)
    expect_identical(i64 / i64, 1.0)
  })
})

test_that("Minus and plus", {
  d64 = c(
    -.Machine$double.base^.Machine$double.digits,
    -.Machine$integer.max,
    -1.0, 0.0, 1.0,
    .Machine$integer.max,
    .Machine$double.base^.Machine$double.digits
  )
  i64 = as.integer64(d64)
  expect_true(identical.integer64(i64 - 1.0 + 1.0, i64))
  expect_true(identical.integer64(i64 + 1.0 - 1.0, i64))
})

test_that("Minus and plus edge cases and 'rev'", {
  # UBSAN signed integer overflow expected for type 'long long int'
  # This is a false UBSAN alarm because overflow is detected and NA returned
  expect_warning(
    expect_true(identical.integer64(
      lim.integer64() + 1.0 - 1.0,
      c(lim.integer64()[1L], NA)
    )),
    "NAs produced by integer64 overflow",
    fixed = TRUE
  )
  expect_warning(
    expect_true(identical.integer64(
      rev(lim.integer64()) - 1.0 + 1.0,
      c(lim.integer64()[2L], NA)
    )),
    "NAs produced by integer64 overflow",
    fixed = TRUE
  )
})

test_that("Logical operators", {
  expect_true(identical.integer64(
    !c(NA, -1:1),
    !c(as.integer64(NA), -1:1)
  ))

  xi = rep(c(NA, -1:1), 4L)
  xi64 = as.integer64(xi)
  yi = rep(c(NA, -1:1), each=4L)
  yi64 = as.integer64(yi)

  expect_true(identical.integer64(xi64 & yi64, xi & yi))
  expect_true(identical.integer64(xi64 | yi64, xi | yi))
  expect_true(identical.integer64(xor(xi64, yi64), xor(xi, yi)))
})

test_that("Comparison operators", {
  xi = rep(c(NA, -1:1), 4L)
  xi64 = as.integer64(xi)
  yi = rep(c(NA, -1:1), each=4L)
  yi64 = as.integer64(yi)

  expect_true(identical.integer64(xi64 == yi64, xi == yi))
  expect_true(identical.integer64(xi64 != yi64, xi != yi))
  expect_true(identical.integer64(xi64 > yi64, xi > yi))
  expect_true(identical.integer64(xi64 >= yi64, xi >= yi))
  expect_true(identical.integer64(xi64 < yi64, xi < yi))
  expect_true(identical.integer64(xi64 <= yi64, xi <= yi))
})

with_parameters_test_that("{operator} with integer64 vs {class} (returning integer64):", {
  withr::local_seed(42)

  if (getRversion() <= "3.6.0" && operator == "^")
    x32 = 1:10 # there seems to be an issue with negative values with the `^` operator in ancient
  else
    x32 = c(-10:-1, 1:10)
  x64 = as.integer64(x32)
  y = sample(x32)
  eval(parse(text=paste0("y = as.", class, "(y)")))

  op = match.fun(operator)
  maybe_cast = if (operator %in% c("+", "-", "*", "^", "%%", "%/%")) as.integer64 else identity

  expected = tryCatch(maybe_cast(op(x32, y)), error=conditionMessage)
  actual = tryCatch(op(x64, y), error=conditionMessage)
  expect_identical(actual, expected)
  
  expected = tryCatch(maybe_cast(op(y, x32)), error=conditionMessage)
  actual = tryCatch(op(y, x64), error=conditionMessage)
  expect_identical(actual, expected)
}, 
  .cases = expand.grid(
    operator=c("+", "-", "*", "/", "^", "%%", "%/%", "<", "<=", "==", ">=", ">", "!=", "&", "|", "xor"),
    class=c("integer", "double", "logical"),
    stringsAsFactors=FALSE
  )
)

with_parameters_test_that("{operator} with integer64 vs. {class} (not returning integer64):", {
  skip_unless_r(">= 4.3.0")
  withr::local_seed(42)

  x32 = c(-10:-1, 1:10)
  x64 = as.integer64(x32)
  y = sample(x32)
  eval(parse(text=paste0("y = as.", class, "(as.double(y)", if (class == "difftime") ', units = "secs"', ")")))
    
  op = match.fun(as.character(operator))
  test_e = tryCatch(op(x32, y), error=conditionMessage)
  test_a = tryCatch(op(x64, y), error=conditionMessage)
  expect_identical(test_a, test_e)
  
  test_e = tryCatch(op(y, x32), error=conditionMessage)
  test_a = tryCatch(op(y, x64), error=conditionMessage)
  expect_identical(test_a, test_e)

  }, 
  .cases = expand.grid(
    operator = c("+", "-", "*", "/", "^", "%%", "%/%", "<", "<=", "==", ">=", ">", "!=", "&", "|", "xor"),
    class = c("complex", "Date", "POSIXct", "POSIXlt", "difftime")
  )
)