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


def assert_readline(payload, size, expected):
    body = Body(BytesIO(payload))
    t.eq(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"))
    t.eq(body.readline(4), b"abc\n")
    t.eq(body.readline(), b"def")


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


def test_readline_no_new_line():
    body = Body(BytesIO(b"abcdef"))
    t.eq(body.readline(), b"abcdef")
    body = Body(BytesIO(b"abcdef"))
    t.eq(body.readline(2), b"ab")
    t.eq(body.readline(2), b"cd")
    t.eq(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)
    print(reader.getvalue())
    t.eq(body.readline(), b"bc\n")
    t.eq(body.readline(), b"defg\n")
    t.eq(body.readline(), b"hi")


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