#!/usr/bin/env python3
"""Write the pinned source photograph the int_hyper integer-codec vectors (the
pretrained mbt2018_mean, exported to integers) are regenerated from.

    python tools/wai_sota_source_image.py <out.png>

The image is a 256x256 crop of `skimage.data.astronaut()` — a photograph that
ships inside the scikit-image wheel and is documented there as public domain
(NASA; "No known copyright restrictions, released into the public domain"). It
is pinned by the SHA-256 of the cropped RGB bytes, so a different image can never
be substituted silently: a mismatch is an error, not a warning.

A real photograph, rather than a synthetic pattern, is what makes the quality
check meaningful: the integer decode is checked against the same model's float
decode on natural-image content, and must cost at most 1 dB there
(tests/int_hyper_synth.rs). That bar is relative, on this one image; it says
nothing about how the model compares with other codecs, or about other images.
The 42.6 dB development figure for this codec was taken on a different
photograph that is not in this repository.
"""
import hashlib
import sys

import numpy as np
from PIL import Image
from skimage import data

CROP = (slice(64, 320), slice(128, 384))  # rows, cols of the 512x512 original
SHA256 = "29cb3aee1a55f9585474d056b65edb0aaebbb80371ba200e85030d63665c19d6"


def main(out: str) -> int:
    rgb = np.ascontiguousarray(data.astronaut()[CROP])
    got = hashlib.sha256(rgb.tobytes()).hexdigest()
    if rgb.shape != (256, 256, 3) or got != SHA256:
        print(f"error: source crop is {rgb.shape} sha256 {got}; pinned (256, 256, 3) {SHA256}. "
              "The scikit-image sample changed — pin the new hash only after reviewing the image.",
              file=sys.stderr)
        return 1
    Image.fromarray(rgb).save(out)
    print(f"wrote {out}: 256x256 RGB, sha256(rgb) {got}")
    return 0


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print(__doc__, file=sys.stderr)
        raise SystemExit(2)
    raise SystemExit(main(sys.argv[1]))