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

Usage: convert_3mf.py <input.3mf> <output.glb> [--plate N]
Prints a JSON summary {glb, plate, volume_cm3, bbox, faces} to stdout.
Negative/modifier/support parts are left out, parts are coloured by their
filament when the project says so, and --plate keeps just that plate.
"""
import argparse
import json

import trimesh
from trimesh.visual import TextureVisuals
from trimesh.visual.material import PBRMaterial

import threemf_stream


def mesh_in(vertices, faces, colour):
    mesh = trimesh.Trimesh(vertices=vertices, faces=faces, process=False)
    if colour:
        rgb = [int(colour[i:i + 2], 16) for i in (1, 3, 5)]
        mesh.visual = TextureVisuals(material=PBRMaterial(
            baseColorFactor=rgb + [255], metallicFactor=0.1, roughnessFactor=0.7))
    return mesh


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("input")
    parser.add_argument("output")
    parser.add_argument("--plate", type=int)
    args = parser.parse_args()

    try:
        meshes, placements = threemf_stream.load(args.input)
        project = threemf_stream.read_project(args.input)
        placements = threemf_stream.printable(project, placements)
        if args.plate is not None:
            placements = threemf_stream.on_plate(project, placements, args.plate)
    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, colour) is stored once; repeated placements become instances of it.
    scene = trimesh.Scene()
    added = set()
    for i, p in enumerate(placements):
        colour = threemf_stream.filament_colour(project, p)
        geom = f"{p.key}|{colour or ''}"
        node = f"part{i}"
        if geom in added:
            scene.graph.update(frame_from=scene.graph.base_frame, frame_to=node, matrix=p.transform, geometry=geom)
        else:
            v, f = meshes[p.key]
            scene.add_geometry(mesh_in(v, f, colour), node_name=node, geom_name=geom, transform=p.transform)
            added.add(geom)
    scene.export(args.output, file_type="glb")

    stats = threemf_stream.measure(meshes, placements)
    ext = stats["extents"]
    print(json.dumps({
        "glb": args.output,
        "plate": args.plate,
        "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__":
    raise SystemExit(main())