"""
- Test Output classes.
- Integration tests (see conftest.py).
"""
import shutil
from fractions import Fraction
from pathlib import Path
from typing import TYPE_CHECKING

import pytest

from corrscope.channel import ChannelConfig
from corrscope.corrscope import default_config, Config, CorrScope, Arguments
from corrscope.outputs import (
    RGB_DEPTH,
    FFmpegOutput,
    FFmpegOutputConfig,
    FFplayOutput,
    FFplayOutputConfig,
)
from corrscope.renderer import RendererConfig, MatplotlibRenderer
from tests.test_renderer import WIDTH, HEIGHT, ALL_ZEROS

if TYPE_CHECKING:
    import pytest_mock


if not shutil.which("ffmpeg"):
    pytestmark = pytest.mark.skip("Missing ffmpeg, skipping output tests")


CFG = default_config(render=RendererConfig(WIDTH, HEIGHT))
NULL_OUTPUT = FFmpegOutputConfig(None, "-f null")


def test_render_output():
    """ Ensure rendering to output does not raise exceptions. """
    renderer = MatplotlibRenderer(CFG.render, CFG.layout, nplots=1, channel_cfgs=None)
    out: FFmpegOutput = NULL_OUTPUT(CFG)

    renderer.render_frame([ALL_ZEROS])
    out.write_frame(renderer.get_frame())

    assert out.close() == 0


def test_output():
    out: FFmpegOutput = NULL_OUTPUT(CFG)

    frame = bytes(WIDTH * HEIGHT * RGB_DEPTH)
    out.write_frame(frame)

    assert out.close() == 0
    # Ensure video is written to stdout, and not current directory.
    assert not Path("-").exists()


# Ensure CorrScope closes pipe to output upon completion.
@pytest.mark.usefixtures("Popen")
def test_close_output(Popen):
    """ FFplayOutput unit test: Ensure ffmpeg and ffplay are terminated when Python
    exceptions occur.
    """

    ffplay_cfg = FFplayOutputConfig()
    output: FFplayOutput
    with ffplay_cfg(CFG) as output:
        pass

    output._pipeline[0].stdin.close.assert_called()
    for popen in output._pipeline:
        popen.wait.assert_called()  # Does wait() need to be called?


# Ensure CorrScope terminates FFplay upon exceptions.
@pytest.mark.usefixtures("Popen")
def test_terminate_ffplay(Popen):
    """ FFplayOutput unit test: Ensure ffmpeg and ffplay are terminated when Python
    exceptions occur.
    """

    ffplay_cfg = FFplayOutputConfig()
    try:
        output: FFplayOutput
        with ffplay_cfg(CFG) as output:
            raise DummyException

    except DummyException:
        for popen in output._pipeline:
            popen.terminate.assert_called()


def sine440_config():
    cfg = default_config(
        channels=[ChannelConfig("tests/sine440.wav")],
        master_audio="tests/sine440.wav",
        end_time=0.5,  # Reduce test duration
    )
    return cfg


@pytest.mark.usefixtures("Popen")
def test_corr_terminate_ffplay(Popen, mocker: "pytest_mock.MockFixture"):
    """ Integration test: Ensure corrscope calls terminate() on ffmpeg and ffplay when
    Python exceptions occur. """

    cfg = sine440_config()
    corr = CorrScope(cfg, Arguments(".", [FFplayOutputConfig()]))

    render_frame = mocker.patch.object(MatplotlibRenderer, "render_frame")
    render_frame.side_effect = DummyException()
    with pytest.raises(DummyException):
        corr.play()

    assert len(corr.outputs) == 1
    output: FFplayOutput = corr.outputs[0]

    for popen in output._pipeline:
        popen.terminate.assert_called()


@pytest.mark.skip("Launches ffmpeg and ffplay processes, creating a ffplay window")
def test_corr_terminate_works():
    """ Ensure that ffmpeg/ffplay terminate quickly after Python exceptions, when
    `popen.terminate()` is called. """

    cfg = sine440_config()
    corr = CorrScope(cfg, Arguments(".", [FFplayOutputConfig()]))
    corr.raise_on_teardown = DummyException

    with pytest.raises(DummyException):
        # Raises `subprocess.TimeoutExpired` if popen.terminate() doesn't work.
        corr.play()


def test_corr_output_without_audio():
    """Ensure running CorrScope with FFmpeg output, with master audio disabled,
    does not crash.
    """
    cfg = sine440_config()
    cfg.master_audio = None

    corr = CorrScope(cfg, Arguments(".", [NULL_OUTPUT]))
    # Should not raise exception.
    corr.play()


def test_render_subfps_one():
    """ Ensure video gets rendered when render_subfps=1.
    This test fails if ceildiv is used to calculate `ahead`.
    """
    from corrscope.outputs import IOutputConfig, Output, register_output

    # region DummyOutput
    class DummyOutputConfig(IOutputConfig):
        pass

    @register_output(DummyOutputConfig)
    class DummyOutput(Output):
        frames_written = 0

        @classmethod
        def write_frame(cls, frame: bytes) -> None:
            cls.frames_written += 1

    assert DummyOutput
    # endregion

    # Create CorrScope with render_subfps=1. Ensure multiple frames are outputted.
    cfg = sine440_config()
    cfg.render_subfps = 1

    corr = CorrScope(cfg, Arguments(".", [DummyOutputConfig()]))
    corr.play()
    assert DummyOutput.frames_written >= 2


def test_render_subfps_non_integer(mocker: "pytest_mock.MockFixture"):
    """ Ensure we output non-integer subfps as fractions,
    and that ffmpeg doesn't crash.
    TODO does ffmpeg understand decimals??
    """

    cfg = sine440_config()
    cfg.fps = 60
    cfg.render_subfps = 7

    # By default, we output render_fps (ffmpeg -framerate) as a fraction.
    assert isinstance(cfg.render_fps, Fraction)
    assert cfg.render_fps != int(cfg.render_fps)
    assert Fraction(1) == int(1)

    corr = CorrScope(cfg, Arguments(".", [NULL_OUTPUT]))
    corr.play()

    # But it seems FFmpeg actually allows decimal -framerate (although a bad idea).
    # from corrscope.corrscope import Config
    # render_fps = mocker.patch.object(Config, 'render_fps',
    #                                  new_callable=mocker.PropertyMock)
    # render_fps.return_value = 60 / 7
    # assert isinstance(cfg.render_fps, float)
    # corr = CorrScope(cfg, '.', outputs=[NULL_OUTPUT])
    # corr.play()


# Possibility: add a test to ensure that we render slightly ahead in time
# when subfps>1, to avoid frames lagging behind audio.


class DummyException(Exception):
    pass


# Tests for Output-dependent performance options


def perf_cfg():
    """ Return config which reduces rendering workload when previewing. """
    cfg = sine440_config()

    # Skip frames.
    assert cfg.end_time == 0.5
    cfg.render_subfps = 2

    # Divide dimensions.
    cfg.render.width = 192
    cfg.render.height = 108
    cfg.render.res_divisor = 1.5

    return cfg


def previews_records(mocker):
    configs = (Config, RendererConfig)

    previews = [mocker.spy(cls, "before_preview") for cls in configs]
    records = [mocker.spy(cls, "before_record") for cls in configs]
    return previews, records


NO_FFMPEG = [[], [FFplayOutputConfig()]]


@pytest.mark.usefixtures("Popen")  # Prevents FFplayOutput from launching processes.
@pytest.mark.parametrize("outputs", NO_FFMPEG)
def test_preview_performance(Popen, mocker: "pytest_mock.MockFixture", outputs):
    """ Ensure performance optimizations enabled
    if all outputs are FFplay or others. """
    get_frame = mocker.spy(MatplotlibRenderer, "get_frame")
    previews, records = previews_records(mocker)

    cfg = perf_cfg()
    corr = CorrScope(cfg, Arguments(".", outputs))
    corr.play()

    # Check that only before_preview() called.
    for p in previews:
        p.assert_called()
    for r in records:
        r.assert_not_called()

    # Check renderer is 128x72
    assert corr.renderer.cfg.width == 128
    assert corr.renderer.cfg.height == 72

    # Ensure subfps is enabled (only odd frames are rendered, 1..29).
    # See CorrScope `should_render` variable.
    assert (
        get_frame.call_count == round(cfg.end_time * cfg.fps / cfg.render_subfps) == 15
    )


YES_FFMPEG = [l + [FFmpegOutputConfig(None)] for l in NO_FFMPEG]


@pytest.mark.usefixtures("Popen")
@pytest.mark.parametrize("outputs", YES_FFMPEG)
def test_record_performance(Popen, mocker: "pytest_mock.MockFixture", outputs):
    """ Ensure performance optimizations disabled
    if any FFmpegOutputConfig is found. """
    get_frame = mocker.spy(MatplotlibRenderer, "get_frame")
    previews, records = previews_records(mocker)

    cfg = perf_cfg()
    corr = CorrScope(cfg, Arguments(".", outputs))
    corr.play()

    # Check that only before_record() called.
    for p in previews:
        p.assert_not_called()
    for r in records:
        r.assert_called()

    # Check renderer is 192x108
    assert corr.renderer.cfg.width == 192
    assert corr.renderer.cfg.height == 108

    # Ensure subfps is disabled.
    assert get_frame.call_count == round(cfg.end_time * cfg.fps) + 1 == 31


# Moved to test_output.py from test_cli.py.
# Because test depends on ffmpeg (not available in Appveyor CI),
# and only test_output.py (not test_cli.py) is skipped in Appveyor.
def test_no_audio(mocker):
    """ Corrscope Config without master audio should work. """
    subdir = "tests"
    wav = "sine440.wav"

    channels = [ChannelConfig(wav)]
    cfg = default_config(master_audio=None, channels=channels, begin_time=100)
    # begin_time=100 skips all actual rendering.

    output = FFmpegOutputConfig(None)
    corr = CorrScope(cfg, Arguments(subdir, [output]))
    corr.play()