import numpy as np
import pytest

from hermes_audio.levels import FLOOR_DB, Activity, rms_dbfs, trigger_window


def sine(f, n, rate=16000, amp=0.5, phase=0.0):
    return (amp * np.sin(2 * np.pi * f * np.arange(n) / rate + phase)).astype(np.float32)


def test_rms_dbfs_known_values():
    assert rms_dbfs(np.ones(100, np.float32)) == pytest.approx(0.0, abs=0.01)
    assert rms_dbfs(sine(440, 16000, amp=1.0)) == pytest.approx(-3.01, abs=0.05)
    assert rms_dbfs(np.zeros(100, np.float32)) == FLOOR_DB or rms_dbfs(np.zeros(100, np.float32)) < -100 + 1
    assert rms_dbfs(np.array([], np.float32)) == FLOOR_DB


def test_trigger_window_starts_on_a_rising_zero_crossing_and_is_phase_locked():
    a = trigger_window(sine(200, 2000, phase=0.3), 256, 512)
    b = trigger_window(sine(200, 2000, phase=2.1), 256, 512)       # a different arrival phase
    assert len(a) == 256 and a[0] >= 0 and abs(a[0]) < 0.2         # begins near a rising zero crossing
    assert np.allclose(a, b, atol=0.12)                            # so both draw the same picture


def test_trigger_window_handles_silence_and_short_buffers():
    assert trigger_window(np.zeros(2000, np.float32)).shape == (256,)
    short = trigger_window(sine(200, 100), 256, 512)
    assert short.shape == (256,)


def run_activity(act, mic_db, spk_db, seconds, t0=0.0, dt=0.05):
    t = t0
    for _ in range(int(seconds / dt)):
        t += dt
        act.update(mic_db, spk_db, t, dt)
    return t


def test_listens_to_a_voice_and_lets_go_after_the_hold():
    a = Activity()
    t = run_activity(a, -62, -100, 3)                  # a quiet room sets the floor
    assert a.state == 'quiet'
    t = run_activity(a, -35, -100, 0.5, t)
    assert a.state == 'listening'
    run_activity(a, -62, -100, 0.8, t)
    assert a.state == 'listening'                      # still holding, through a pause between words
    run_activity(a, -62, -100, 1.0, t + 0.8)
    assert a.state == 'quiet'


def test_a_click_is_not_speech():
    a = Activity()
    t = run_activity(a, -62, -100, 2)
    t = run_activity(a, -30, -100, 0.05, t)            # one 50 ms burst, shorter than on_s
    run_activity(a, -62, -100, 0.1, t)
    assert a.state == 'quiet'


def test_speaking_wins_and_ignores_the_mic():
    a = Activity()
    t = run_activity(a, -62, -100, 2)
    t = run_activity(a, -30, -40, 0.5, t)              # loud mic AND loud speaker monitor
    assert a.state == 'speaking'
    run_activity(a, -30, -100, 0.1, t)
    assert a.state == 'speaking'                       # held
    t2 = run_activity(a, -30, -100, 1.0, t + 0.1)
    assert a.state == 'listening'                      # speaker stopped; the mic is real speech now
    assert t2 > t


def test_a_room_that_is_already_noisy_calibrates_instead_of_listening_forever():
    a = Activity()
    run_activity(a, -43, -100, 5)                      # a steady -43 dBFS noise floor from the start
    assert a.state == 'quiet' and a.mic_threshold_db > -40
    t = run_activity(a, -25, -100, 0.5, 5.0)           # a voice 18 dB above it
    assert a.state == 'listening'
    run_activity(a, -43, -100, 2.0, t)
    assert a.state == 'quiet'


def test_pauses_between_words_do_not_flicker():
    a = Activity()
    t = run_activity(a, -43, -100, 5)
    states = []
    for _ in range(6):                                 # six words, 0.3 s each with 0.3 s gaps
        for level, secs in ((-25, 0.3), (-43, 0.3)):
            for _ in range(int(secs / 0.05)):
                t += 0.05
                states.append(a.update(level, -100, t, 0.05))
    assert states[8:].count('quiet') == 0              # once it starts listening it stays there


def test_quiet_room_noise_peaks_stay_below_the_threshold():
    a = Activity()
    t = run_activity(a, -43, -100, 5)
    flicker = []
    for i in range(200):
        t += 0.05
        flicker.append(a.update(-43 + (3 if i % 7 == 0 else 0), -100, t, 0.05))   # peaks 3 dB over the floor
    assert set(flicker) == {'quiet'}


def test_a_new_steady_noise_is_absorbed_after_a_while():
    a = Activity()
    t = run_activity(a, -60, -100, 5)                  # quiet room
    t = run_activity(a, -35, -100, 1.0, t)
    assert a.state == 'listening'                      # something started
    run_activity(a, -35, -100, 20, t)                  # ...and never stops: a hum, not speech
    assert a.state == 'quiet'