from __future__ import annotations

import hashlib
import json
from pathlib import Path

from PIL import Image


ROOT = Path(__file__).resolve().parents[2]
MANIFEST = ROOT / "design-pipeline/manifests/module-page-backgrounds.json"


def sha256(path: Path) -> str:
    digest = hashlib.sha256()
    with path.open("rb") as stream:
        for chunk in iter(lambda: stream.read(1024 * 1024), b""):
            digest.update(chunk)
    return digest.hexdigest()


def normalize(source: Path, output: Path, width: int, height: int) -> None:
    with Image.open(source) as image:
        image = image.convert("RGB")
        scale = max(width / image.width, height / image.height)
        resized = image.resize(
            (round(image.width * scale), round(image.height * scale)),
            Image.Resampling.LANCZOS,
        )
        left = max(0, (resized.width - width) // 2)
        top = max(0, (resized.height - height) // 2)
        normalized = resized.crop((left, top, left + width, top + height))
        output.parent.mkdir(parents=True, exist_ok=True)
        normalized.save(output, format="PNG", optimize=True)


def main() -> None:
    manifest = json.loads(MANIFEST.read_text(encoding="utf-8"))
    width = int(manifest["width"])
    height = int(manifest["height"])
    report = []
    for item in manifest["backgrounds"]:
        source = ROOT / item["source"]
        output = ROOT / item["output"]
        if not source.is_file():
            raise FileNotFoundError(source)
        normalize(source, output, width, height)
        report.append(
            {
                "module": item["module"],
                "source": item["source"],
                "output": item["output"],
                "size": [width, height],
                "sha256": sha256(output),
            }
        )
    print(json.dumps(report, ensure_ascii=False, indent=2))


if __name__ == "__main__":
    main()