"""Render assets/icon.svg to assets/icon.ico (PNG-compressed entries at the usual Windows sizes).

Run with: uv run python packaging/make_icon.py
"""

import struct
import sys
from pathlib import Path

from PySide6.QtCore import QBuffer, QByteArray, QIODevice, Qt
from PySide6.QtGui import QGuiApplication, QImage, QPainter
from PySide6.QtSvg import QSvgRenderer

SIZES = [16, 24, 32, 48, 64, 128, 256]
ROOT = Path(__file__).resolve().parent.parent


def render_png(renderer: QSvgRenderer, size: int) -> bytes:
    img = QImage(size, size, QImage.Format.Format_ARGB32)
    img.fill(Qt.GlobalColor.transparent)
    painter = QPainter(img)
    painter.setRenderHint(QPainter.RenderHint.Antialiasing)
    renderer.render(painter)
    painter.end()
    data = QByteArray()
    buf = QBuffer(data)
    buf.open(QIODevice.OpenModeFlag.WriteOnly)
    img.save(buf, "PNG")
    return bytes(data)


def main() -> None:
    QGuiApplication(sys.argv[:1])
    renderer = QSvgRenderer(str(ROOT / "assets/icon.svg"))
    pngs = [(size, render_png(renderer, size)) for size in SIZES]
    # ICONDIR header, then one ICONDIRENTRY per image, then the PNG data.
    out = struct.pack("<HHH", 0, 1, len(pngs))
    offset = 6 + 16 * len(pngs)
    for size, png in pngs:
        dim = 0 if size >= 256 else size  # 0 means 256
        out += struct.pack("<BBBBHHII", dim, dim, 0, 0, 1, 32, len(png), offset)
        offset += len(png)
    out += b"".join(png for _, png in pngs)
    (ROOT / "assets/icon.ico").write_bytes(out)
    # The app loads this at runtime (window/taskbar icon), so it lives inside the package.
    (ROOT / "src/mtga_assistant/icon.png").write_bytes(dict(pngs)[256])
    print(f"wrote assets/icon.ico ({len(out)} bytes) and src/mtga_assistant/icon.png")


if __name__ == "__main__":
    main()