from Raw Vectors

# target <- readBin(pipe("perl -e 'print pack(q{a8}, q{packrats})'", "rb"), raw(), n=8)
target_no_pad <- as.raw(c(0x70, 0x61, 0x63, 0x6b, 0x72, 0x61, 0x74, 0x73))
target_null_pad <- as.raw(c(0x70, 0x61, 0x63, 0x6b, 0x72, 0x61, 0x74, 0x73, 0, 0))
target_space_pad <- as.raw(c(0x70, 0x61, 0x63, 0x6b, 0x72, 0x61, 0x74, 0x73, 0x20, 0x20))

## Null-padded string
msg <- "null padded string pattern - no pad"
a8 <- pack("a8", "packrats")
expect_identical(a8, target_no_pad, info = msg)
expect_identical(unpack("a8", a8), list("packrats"), info = msg)

msg <- "null padded string pattern - 3 null pad"
a10 <- pack("a10", "packrats")
expect_identical(a10, target_null_pad, info = msg)
expect_identical(unpack("a10", a10), list("packrats"), info = msg)

## Space-padded string
msg <- "space padded string pattern - no pad"
A8 <- pack("A8", "packrats")
expect_identical(A8, target_no_pad, info = msg)
expect_identical(unpack("A8", A8), list("packrats"), info = msg)

msg <- "space padded string pattern - 3 space pad"
A10 <- pack("A10", "packrats")
expect_identical(A10, target_space_pad, info = msg)
expect_identical(unpack("A10", A10), list("packrats"), info = msg)
# % perl -le '$x=pack "A10", "packrats"; $y=unpack "A10", $x; print "{$_}" for $x, $y'
# {packrats  }
# {packrats}

## Null-padded string with star
msg <- "null padded string* - no pad"
a_star <- pack("a*", "packrats")
expect_identical(a_star, target_no_pad, info = msg)
expect_identical(unpack("a*", a_star), list("packrats"), info = msg)
# % perl -le '$x=pack "a*", "packrats"; $y=unpack "a*", $x; print "{$_}" for $x, $y'
# {packrats}
# {packrats}

msg <- "space padded string* - no pad"
A_star <- pack("A*", "packrats")
expect_identical(A_star, target_no_pad, info = msg)
expect_identical(unpack("A*", A_star), list("packrats"), info = msg)
# % perl -le '$x=pack "A*", "packrats"; $y=unpack "A*", $x; print "{$_}" for $x, $y'
# {packrats}
# {packrats}


## TODO Space-padded string with stars


## Something to work with for the tests below
bvec <- c(1,1,0,1,0,0,1,0)

# Binary vector, little-endian
msg <- "little-endian binary vector"
x <- pack("b", as.raw(bvec))
expect_identical(x, as.raw(sum(bvec * 2^(0:7))), info = msg)  # 0x4b
expect_identical(unpack("b", x), list(as.raw(bvec)), info = msg)

## Binary vector, big-endian
msg <- "big-endian binary vector"
x <- pack("B", as.raw(bvec))
expect_identical(x, as.raw(sum(bvec * 2^(7:0))), info = msg)
expect_identical(unpack("B", x), list(as.raw(bvec)), info = msg)

# TODO "b" and "B" with counts


## Unsigned char (8 bits)
msg <- "8-bit unsigned char"
r <- as.raw(c(0x00, 0xff))
x <- pack("C C", 0L, 255L)  # min and max values
expect_identical(x, r, info = msg)
expect_identical(unpack("C C", r), list(0L, 255L), info = msg)

msg <- "8-bit unsigned char < 0"
expect_error(pack("C", -1L), info = msg)
# Unsure how to test unpack() here. You can always unpack a byte as an
# unsigned 8-bit int, even though it would be incorrect if that wasn't
# how it was packed.
#expect_error(unpack("C", c(0x00, 0xff)), list(-1L), info = msg)

msg <- "8-bit unsigned char > 255"
expect_error(pack("C", 256L), info = msg)
# Unsure how to test unpack() here. You can always unpack a byte as an
# unsigned 8-bit int, even though it would be incorrect if that wasn't
# how it was packed.
#expect_error(unpack("C", c(0x00, 0xff)), list(256L), info = msg)

# TODO "C" with counts

## Unsigned 16-bit integer, little-endian
msg <- "16-bit unsigned integer, little-endian"
x <- pack("v", 12345)
# y <- readBin(pipe("perl -e 'print pack(q{v}, 12345)'", "rb"), raw(), n=2)
y <- as.raw(c(0x39, 0x30))
expect_identical(x, y, info = msg)
expect_identical(unpack("v", x), list(12345), info = msg)

## Unsigned 32-bit integer, little-endian
msg <- "32-bit unsigned integer, little-endian"
x <- pack("V", 1234567)
# y <- readBin(pipe("perl -e 'print pack(q{V}, 1234567)'", "rb"), raw(), n=4)
y <- as.raw(c(0x87, 0xd6, 0x12, 0))
expect_identical(x, y, info = msg)
expect_identical(unpack("V", x), list(1234567), info = msg)

## Null bytes
x <- pack("x", "foo")  # input data doesn't matter
expect_identical(x, as.raw(0), info = "null bytes")
expect_identical(unpack("x", x), list(), info = "null bytes")

# TODO "x" with counts

# Native 4-byte float
msg <- "native 4-byte float"
x <- pack("f", 123.45)
# y <- readBin(pipe("perl -e 'print pack(q{f}, 123.45)'", "rb"), raw(), n=4)
y <- as.raw(c(0x66, 0xe6, 0xf6, 0x42))
if (.Platform$endian == "big") {
    # y was generated on little-endian machine
    y <- rev(y)
}
eps <- sqrt(2^-23)
expect_equal(x, y, tolerance = eps, info = msg)
expect_equal(unpack("f", x), list(123.45), tolerance = eps, info = msg)
x <- pack("f", "123.45")  # Should coerce input to number, the same way Perl does
expect_equal(x, y, tolerance = eps)

# Native 8-byte float
msg <- "native 8-byte float"
x <- pack("d", 123.45)
# y <- readBin(pipe("perl -e 'print pack(q{d}, 123.45)'", "rb"), raw(), n=8)
y <- as.raw(c(0xcd, 0xcc, 0xcc, 0xcc, 0xcc, 0xdc, 0x5e, 0x40))
if (.Platform$endian == "big") {
    # y was generated on little-endian machine
    y <- rev(y)
}
eps <- sqrt(2^-52)
expect_equal(x, y, tolerance = eps, info = msg)
expect_equal(unpack("d", x), list(123.45), tolerance = eps, info = msg)
x <- pack("d", "123.45")  # Should coerce input to number, the same way Perl does
expect_equal(x, y, tolerance = eps)

# Raw bytes
msg <- "raw bytes"
x <- as.raw(c(0xcd, 0x40)) # No corresponding "H" pack() field
expect_identical(unpack("H",  x), list(x[1]), info = msg)
expect_identical(unpack("H1", x), list(x[1]), info = msg)
expect_identical(unpack("H2", x), list(x), info = msg)
expect_identical(unpack("H*", x), list(x), info = msg)

# TODO "/" count handling