#!/usr/bin/env python3
"""Print a 3MF project's plates and filaments as JSON, without loading geometry.

Usage: threemf_info.py <file.3mf> [--images DIR]
With --images, each plate's preview is written to DIR/<n>.png and DIR/<n>-small.png.
"""
import argparse
import json
import os
import zipfile

import threemf_stream


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("input")
    parser.add_argument("--images")
    args = parser.parse_args()

    try:
        project = threemf_stream.read_project(args.input)
        if args.images and project["plates"]:
            os.makedirs(args.images, exist_ok=True)
            with zipfile.ZipFile(args.input) as z:
                for plate in project["plates"]:
                    for name, suffix in ((plate["thumbnail"], ""), (plate["thumbnail_small"], "-small")):
                        if name:
                            with open(os.path.join(args.images, f"{plate['index']}{suffix}.png"), "wb") as out:
                                out.write(z.read(name))
    except Exception as exc:
        print(json.dumps({"error": f"could not read 3MF: {str(exc)[:200]}"}))
        return 1

    print(json.dumps({
        "plates": [{"index": p["index"], "name": p["name"], "objectCount": len(p["objects"]),
                    "thumbnail": bool(p["thumbnail"] or p["thumbnail_small"])} for p in project["plates"]],
        "filaments": project["filaments"],
    }))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())