import pytest

import app.tts.piper as piper
from app.tts.voices import VOICES


@pytest.fixture(autouse=True)
def _fake_piper_synth(monkeypatch):
    async def _fake_synthesize(self, text):
        return b"fake-wav-bytes"

    monkeypatch.setattr(piper.PiperTTS, "synthesize", _fake_synthesize)


def _capture_effects_call(monkeypatch):
    calls = []

    def _fake_apply_effects(wav_bytes, **kwargs):
        calls.append(kwargs)
        return wav_bytes

    monkeypatch.setattr(piper, "apply_effects", _fake_apply_effects)
    return calls


@pytest.mark.asyncio
async def test_zero_instability_keeps_profile_defaults(monkeypatch):
    calls = _capture_effects_call(monkeypatch)
    voice = VOICES["lessac"]

    await piper.synthesize_spirit_voice("hello", voice, {"noise": 0.03, "bitcrush": 0})

    assert calls[0]["noise_level"] == pytest.approx(0.03)
    assert calls[0]["bitcrush_bits"] == 0


@pytest.mark.asyncio
async def test_instability_increases_noise_level(monkeypatch):
    calls = _capture_effects_call(monkeypatch)
    voice = VOICES["lessac"]

    await piper.synthesize_spirit_voice(
        "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=1.0
    )

    # Meaningfully louder than the clean baseline, but not blown out.
    assert calls[0]["noise_level"] > 0.03
    assert calls[0]["noise_level"] <= 0.1


@pytest.mark.asyncio
async def test_noise_level_scales_monotonically_with_instability(monkeypatch):
    voice = VOICES["lessac"]
    noise_levels = []
    for instability in (0.0, 0.25, 0.5, 0.75, 1.0):
        calls = _capture_effects_call(monkeypatch)
        await piper.synthesize_spirit_voice(
            "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=instability
        )
        noise_levels.append(calls[0]["noise_level"])

    assert noise_levels == sorted(noise_levels)
    assert noise_levels[0] < noise_levels[-1]


@pytest.mark.asyncio
async def test_bitcrush_stays_off_below_threshold(monkeypatch):
    voice = VOICES["lessac"]
    for instability in (0.0, 0.2, 0.5):
        calls = _capture_effects_call(monkeypatch)
        await piper.synthesize_spirit_voice(
            "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=instability
        )
        assert calls[0]["bitcrush_bits"] == 0


@pytest.mark.asyncio
async def test_bitcrush_kicks_in_above_threshold(monkeypatch):
    calls = _capture_effects_call(monkeypatch)
    voice = VOICES["lessac"]

    await piper.synthesize_spirit_voice(
        "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=1.0
    )

    assert calls[0]["bitcrush_bits"] > 0
    assert calls[0]["bitcrush_bits"] < 16


@pytest.mark.asyncio
async def test_instability_is_clamped_to_unit_range(monkeypatch):
    calls = _capture_effects_call(monkeypatch)
    voice = VOICES["lessac"]

    await piper.synthesize_spirit_voice(
        "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=5.0
    )
    clamped_high = calls[0]

    calls = _capture_effects_call(monkeypatch)
    await piper.synthesize_spirit_voice(
        "hello", voice, {"noise": 0.03, "bitcrush": 0}, instability=1.0
    )
    at_one = calls[0]

    assert clamped_high == at_one


@pytest.mark.asyncio
async def test_instability_adds_on_top_of_profile_bitcrush(monkeypatch):
    calls = _capture_effects_call(monkeypatch)
    voice = VOICES["lessac"]

    await piper.synthesize_spirit_voice(
        "hello", voice, {"noise": 0.03, "bitcrush": 4}, instability=1.0
    )

    assert calls[0]["bitcrush_bits"] > 4