#!/usr/bin/env python3
"""Generate PNG icons from SVG for PWA."""

from __future__ import annotations

import pathlib
import struct
import zlib

ROOT = pathlib.Path(__file__).resolve().parents[1]
SVG = ROOT / "public" / "icon.svg"


def _png_chunk(tag: bytes, data: bytes) -> bytes:
    return struct.pack(">I", len(data)) + tag + data + struct.pack(">I", zlib.crc32(tag + data) & 0xFFFFFFFF)


def write_simple_png(path: pathlib.Path, size: int) -> None:
    """Minimal orange/blue square PNG — no external deps."""
    raw_rows = []
    for y in range(size):
        row = b"\x00"
        for x in range(size):
            cx, cy = size / 2, size / 2
            dist = ((x - cx) ** 2 + (y - cy) ** 2) ** 0.5
            if dist < size * 0.42:
                row += bytes([255, 159, 67])  # orange fish body
            elif y < size * 0.15 or y > size * 0.92:
                row += bytes([11, 61, 92])
            else:
                row += bytes([11, 61, 92])
        raw_rows.append(row)
    compressed = zlib.compress(b"".join(raw_rows), 9)
    ihdr = struct.pack(">IIBBBBB", size, size, 8, 2, 0, 0, 0)
    png = b"\x89PNG\r\n\x1a\n"
    png += _png_chunk(b"IHDR", ihdr)
    png += _png_chunk(b"IDAT", compressed)
    png += _png_chunk(b"IEND", b"")
    path.write_bytes(png)


def main() -> None:
    out = ROOT / "public" / "icon-192.png"
    write_simple_png(out, 192)
    print(f"Wrote {out}")


if __name__ == "__main__":
    main()