# JTFTP - Python/AsyncIO TFTP Server
# Copyright (C) 2022 Jeffrey C. Ollie
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.

import time
from itertools import count
from itertools import islice

import pytest
from jtftp.util import iterlast
from jtftp.util import timed_caller


def test_iterlast_3():
    assert list(iterlast([1, 2, 3])) == [(False, 1), (False, 2), (True, 3)]


def test_iterlast_0():
    assert list(iterlast([])) == []


def test_iterlast_1():
    assert list(iterlast([1])) == [(True, 1)]


def test_iterlast_infinite():
    assert list(islice(iterlast(count(1)), 3)) == [(False, 1), (False, 2), (False, 3)]


@pytest.mark.asyncio
async def test_timed_caller():
    latency = 250000
    r = []
    t = [time.monotonic_ns()]

    async def c():
        end = time.monotonic_ns()
        r.append(("c", (end - t[-1]) < latency))
        t.append(end)

    async def l():
        end = time.monotonic_ns()
        r.append(("l", (end - t[-1]) < latency))
        t.append(end)

    await timed_caller((0, 0, 0), c, l)
    assert r == [("c", True), ("c", True), ("l", True)]


@pytest.mark.asyncio
async def test_timed_caller_no_timings():
    with pytest.raises(ValueError):

        async def c():
            pass

        async def l():
            pass

        await timed_caller([], c, l)


@pytest.mark.asyncio
async def test_timed_caller_negative_timings():
    with pytest.raises(ValueError):

        async def c():
            pass

        async def l():
            pass

        await timed_caller([0, -1, 0], c, l)