#!/usr/bin/env python3
"""Convert a 3MF (incl. Bambu/MakerWorld production-extension files) to GLB.

Usage: convert_3mf.py <input.3mf> <output.glb>
Prints a JSON summary {glb, volume_cm3, bbox, faces} to stdout.
"""
import sys
import json

import trimesh

import threemf_stream


def main():
    if len(sys.argv) != 3:
        print(json.dumps({"error": "usage: convert_3mf.py <in.3mf> <out.glb>"}))
        return 2

    in_path, out_path = sys.argv[1], sys.argv[2]
    try:
        meshes, placements = threemf_stream.load(in_path)
    except Exception as exc:
        print(json.dumps({"error": f"could not read 3MF: {str(exc)[:200]}"}))
        return 1
    if not placements:
        print(json.dumps({"error": "no geometry found in 3MF"}))
        return 1

    # Each object is stored once; repeated placements become instances of it.
    scene = trimesh.Scene()
    added = set()
    for i, (key, transform) in enumerate(placements):
        node = f"part{i}"
        if key in added:
            scene.graph.update(frame_from=scene.graph.base_frame, frame_to=node, matrix=transform, geometry=key)
        else:
            v, f = meshes[key]
            scene.add_geometry(trimesh.Trimesh(vertices=v, faces=f, process=False),
                               node_name=node, geom_name=key, transform=transform)
            added.add(key)
    scene.export(out_path, file_type="glb")

    stats = threemf_stream.measure(meshes, placements)
    ext = stats["extents"]
    print(json.dumps({
        "glb": out_path,
        "bbox": {"x": round(ext[0], 3), "y": round(ext[1], 3), "z": round(ext[2], 3)},
        "faces": stats["faces"],
        # mm^3 -> cm^3 to match the rest of the app
        "volume_cm3": round(stats["volume"] / 1000.0, 3),
    }))
    return 0


if __name__ == "__main__":
    sys.exit(main())