import numpy as np
import pytest

from hermes_face.render import H, STATES, W, FaceRenderer, box_blur


def run(r, seconds, t0=0.0, fps=30):
    t, frame = t0, None
    for _ in range(int(seconds * fps)):
        t += 1 / fps
        frame = r.frame(t, 1 / fps)
    return frame, t


def brightness(frame):
    return float(frame.astype(np.float32).mean())


@pytest.mark.parametrize('state', STATES)
@pytest.mark.parametrize('style', ['phosphor', 'vector'])
def test_every_state_draws_something(state, style):
    frame, _ = run(FaceRenderer(style=style, state=state, seed=0), 3)
    assert frame.shape == (H, W, 3) and frame.dtype == np.uint8
    assert frame.max() > 100


def test_sleeping_is_dimmer_than_idle():
    idle, _ = run(FaceRenderer(state='idle', seed=0), 4)
    asleep, _ = run(FaceRenderer(state='sleeping', seed=0), 4)
    assert brightness(asleep) < 0.8 * brightness(idle)


def test_wakes_up():
    r = FaceRenderer(state='sleeping', seed=0)
    _, t = run(r, 2)
    r.set_state('idle', t)
    frame, _ = run(r, 3, t)
    idle, _ = run(FaceRenderer(state='idle', seed=0), 3)
    assert r.a['open'] > 0.9 and abs(brightness(frame) - brightness(idle)) < 0.2 * brightness(idle)


def test_looking_returns_to_the_state_it_interrupted():
    r = FaceRenderer(state='thinking', seed=0)
    _, t = run(r, 1)
    r.set_state('looking', t)
    assert r.state == 'looking'
    run(r, 2, t)
    assert r.state == 'thinking'


def test_unknown_state_rejected():
    with pytest.raises(ValueError):
        FaceRenderer().set_state('dancing', 0.0)


def test_pan_moves_the_eyes():
    def centroid_x(pan):
        r = FaceRenderer(state='idle', seed=0, jitter=0)
        r.set_pose(pan, 0)
        frame, _ = run(r, 2)
        lum = frame.astype(np.float32).sum(axis=(0, 2))
        return float((lum * np.arange(W)).sum() / lum.sum())
    assert centroid_x(-60) > centroid_x(0) > centroid_x(60)   # +pan = robot's left = viewer's right


def test_box_blur_conserves_energy():
    b = np.zeros((H, W), np.float32)
    b[120, 120] = 1.0
    out = box_blur(b, 2)
    assert abs(out.sum() - 1.0) < 1e-3
    assert np.allclose(out[118:123, 118:123], 1 / 25, atol=1e-5)


def test_rgb565_frame_matches_rgb_frame():
    a = FaceRenderer(state='idle', seed=3)
    b = FaceRenderer(state='idle', seed=3)
    rgb, raw = None, None
    for i in range(1, 40):
        rgb = a.frame(i / 30, 1 / 30)
        raw = b.frame(i / 30, 1 / 30, 'rgb565')
    assert len(raw) == H * W * 2
    px = np.frombuffer(raw, '>u2').reshape(H, W)
    assert np.array_equal(px >> 11, rgb[..., 0] >> 3)
    assert np.array_equal((px >> 5) & 0x3F, rgb[..., 1] >> 2)
    assert np.array_equal(px & 0x1F, rgb[..., 2] >> 3)


@pytest.mark.parametrize('rotation', [90, 180, 270])
def test_rotation_turns_the_frame_counter_clockwise(rotation):
    base = FaceRenderer(state='idle', seed=5, rotation=0)
    turned = FaceRenderer(state='idle', seed=5, rotation=rotation)
    a = b = None
    for i in range(1, 30):
        a = base.frame(i / 30, 1 / 30)
        b = turned.frame(i / 30, 1 / 30)
    assert np.array_equal(b, np.rot90(a, rotation // 90))


def test_bad_rotation_rejected():
    with pytest.raises(ValueError):
        FaceRenderer(rotation=45)