"""A ginger tabby texture and a purr loop for Marmalade, the cat on the window seat.

  local/hear-venv/Scripts/python.exe cat_assets.py      (writes tabby.png 256px and purr.wav here)

Tabby: warm ginger with soft darker stripes running around the body (sphere U wraps around), paler underneath
(low V). Purr: ~26 pulses a second of low, chesty filtered noise, louder on the exhale, quieter on the inhale,
two breaths in a seamless 5.6 s loop. Claude Opus 5.5 (Tessel), 2026-10-10."""
import wave
from pathlib import Path

import numpy as np
from PIL import Image, ImageFilter

HERE = Path(__file__).parent
rng = np.random.default_rng(11)

# ---- tabby ----
S = 256
v, u = np.mgrid[0:S, 0:S].astype(np.float32) / S          # rows = V (bottom..top after flip), cols = U
base = np.array([201, 120, 58], np.float32)                # ginger
dark = np.array([150, 76, 32], np.float32)
cream = np.array([236, 205, 160], np.float32)
wob = np.asarray(Image.fromarray((rng.random((8, 8)) * 255).astype(np.uint8)).resize((S, S), Image.BICUBIC),
                 np.float32) / 255
stripe = 0.5 + 0.5 * np.sin(2 * np.pi * (u * 9 + 0.35 * wob + 0.08 * np.sin(2 * np.pi * v * 3)))
stripe = np.clip((stripe - 0.55) * 3.0, 0, 1)             # narrow-ish dark bands
fur = np.asarray(Image.fromarray((rng.random((S, S)) * 255).astype(np.uint8)).filter(ImageFilter.GaussianBlur(0.7)),
                 np.float32) / 255
img = base * (1 - stripe[..., None] * 0.85) + dark * (stripe[..., None] * 0.85)
under = np.clip((v - 0.72) / 0.2, 0, 1)[..., None]        # image rows near the bottom = low V = underside
img = img * (1 - under) + cream * under
img *= (0.9 + 0.2 * fur[..., None])
Image.fromarray(np.clip(img, 0, 255).astype(np.uint8)).save(HERE / "tabby.png")
print(HERE / "tabby.png")

# ---- purr ----
SR = 44100  # SL wants 44.1 kHz
BREATH = 2.8
N = int(SR * BREATH * 2)
t = np.arange(N) / SR
X = np.fft.rfft(rng.standard_normal(N))
f = np.fft.rfftfreq(N, 1 / SR)
X *= (1 / (1 + (40 / np.maximum(f, 1)) ** 4)) * (1 / (1 + (f / 420) ** 3))
rumble = np.fft.irfft(X, N)
rumble /= np.abs(rumble).max()
phase = (t % BREATH) / BREATH                              # 0..1 within a breath
exhale = phase < 0.55
rate = np.where(exhale, 25.0, 27.5)                        # slightly faster on the inhale
pulse_phase = np.cumsum(rate) / SR
# rate changes keep a whole number of pulses per loop: rescale the phase so it wraps cleanly
pulse_phase *= round(pulse_phase[-1]) / pulse_phase[-1]
pulse = (0.5 + 0.5 * np.cos(2 * np.pi * pulse_phase)) ** 3
ex = np.sin(np.pi * np.clip(phase / 0.55, 0, 1)) ** 0.6
inh = 0.45 * np.sin(np.pi * np.clip((phase - 0.55) / 0.45, 0, 1)) ** 0.8
env = np.where(exhale, ex, inh)
sig = rumble * pulse * env
sig += 0.15 * np.sin(2 * np.pi * pulse_phase) * env       # a little body at the pulse rate itself
sig /= np.abs(sig).max()
pcm = (sig * 0.8 * 32767).astype("<i2")
with wave.open(str(HERE / "purr.wav"), "wb") as w:
    w.setnchannels(1); w.setsampwidth(2); w.setframerate(SR); w.writeframes(pcm.tobytes())
print(HERE / "purr.wav", round(N / SR, 2), "s")