import t
from gunicorn.http.body import Body
from gunicorn.six import BytesIO


def assert_readline(payload, size, expected):
    body = Body(BytesIO(payload))
    assert body.readline(size) == expected


def test_readline_empty_body():
    assert_readline(b"", None, b"")
    assert_readline(b"", 1, b"")


def test_readline_zero_size():
    assert_readline(b"abc", 0, b"")
    assert_readline(b"\n", 0, b"")


def test_readline_new_line_before_size():
    body = Body(BytesIO(b"abc\ndef"))
    assert body.readline(4) == b"abc\n"
    assert body.readline() == b"def"


def test_readline_new_line_after_size():
    body = Body(BytesIO(b"abc\ndef"))
    assert body.readline(2) == b"ab"
    assert body.readline() == b"c\n"


def test_readline_no_new_line():
    body = Body(BytesIO(b"abcdef"))
    assert body.readline() == b"abcdef"
    body = Body(BytesIO(b"abcdef"))
    assert body.readline(2) == b"ab"
    assert body.readline(2) == b"cd"
    assert body.readline(2) == b"ef"


def test_readline_buffer_loaded():
    reader = BytesIO(b"abc\ndef")
    body = Body(reader)
    body.read(1) # load internal buffer
    reader.write(b"g\nhi")
    reader.seek(7)
    assert body.readline() == b"bc\n"
    assert body.readline() == b"defg\n"
    assert body.readline() == b"hi"


def test_readline_buffer_loaded_with_size():
    body = Body(BytesIO(b"abc\ndef"))
    body.read(1)  # load internal buffer
    assert body.readline(2) == b"bc"
    assert body.readline(2) == b"\n"
    assert body.readline(2) == b"de"
    assert body.readline(2) == b"f"