"""Import a browser-produced PLY in pinned Blender 5.2 and emit mapped fields."""

import hashlib
import json
import sys
from pathlib import Path

import bpy


def sha256_file(path):
    digest = hashlib.sha256()
    with open(path, "rb") as handle:
        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
            digest.update(chunk)
    return digest.hexdigest()


def attr_values(attribute):
    values = []
    for item in attribute.data:
        if attribute.data_type == "FLOAT_COLOR": values.append([float(value) for value in item.color])
        elif attribute.data_type == "FLOAT_VECTOR": values.append([float(value) for value in item.vector])
        elif attribute.data_type == "FLOAT": values.append(float(item.value))
        elif attribute.data_type == "INT": values.append(int(item.value))
    return values


def main(ply_path, report_path):
    ply_path = Path(ply_path).resolve(); report_path = Path(report_path).resolve()
    bpy.ops.wm.read_factory_settings(use_empty=True)
    result = bpy.ops.wm.ply_import(filepath=str(ply_path), import_colors="SRGB", import_attributes=True, forward_axis="NEGATIVE_Z", up_axis="Y", global_scale=1.0)
    objects = [obj for obj in bpy.context.scene.objects if obj.type == "MESH"]
    if "FINISHED" not in result or not objects: raise RuntimeError("Blender PLY import did not produce a mesh")
    obj = objects[0]; mesh = obj.data; mesh.calc_loop_triangles()
    wanted = [attribute for attribute in mesh.attributes if attribute.name in {"Col", "temperature", "label"}]
    report = {
        "schemaVersion": 1,
        "operation": "DESKTOP_IMPORT_WEB_PLY",
        "sourceSha256": sha256_file(ply_path),
        "sourceBytes": ply_path.stat().st_size,
        "objectCount": len(objects),
        "vertexCount": len(mesh.vertices),
        "polygonCount": len(mesh.polygons),
        "triangleCount": len(mesh.loop_triangles),
        "positions": [[float(value) for value in vertex.co] for vertex in mesh.vertices],
        "attributes": [{"name": attribute.name, "dataType": attribute.data_type, "domain": attribute.domain, "values": attr_values(attribute)} for attribute in wanted],
    }
    report_path.parent.mkdir(parents=True, exist_ok=True); report_path.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print("ply-web-roundtrip-desktop-imported vertices=%s faces=%s attrs=%s" % (report["vertexCount"], report["triangleCount"], len(report["attributes"])))


if __name__ == "__main__":
    args = sys.argv[sys.argv.index("--") + 1 :] if "--" in sys.argv else []
    if len(args) != 2: raise SystemExit("usage: blender --background --python check-ply-web-roundtrip.py -- PLY REPORT")
    main(args[0], args[1])