#!/usr/bin/env python3
import hashlib
import json
import os
import pathlib
import sys
import tempfile

import bpy


def rounded(value):
    return round(float(value), 6)


def report():
    data = bpy.data.pointclouds.get("WebGapPointCloud")
    if data is None:
        raise RuntimeError("WebGapPointCloud is missing")
    positions = [0.0] * (len(data.points) * 3)
    data.points.foreach_get("co", positions)
    radius = data.attributes.get("radius")
    radii = [0.0] * len(data.points)
    if radius is not None:
        radius.data.foreach_get("value", radii)
    return {
        "id": "pointcloud:" + data.name,
        "name": data.name,
        "pointCount": len(data.points),
        "controlPoints": [rounded(value) for value in positions],
        "radii": [rounded(value) for value in radii],
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-pointcloud-desktop.py -- FIXTURE REPORT")
    fixture, output = (pathlib.Path(value).resolve() for value in arguments)
    bpy.ops.wm.open_mainfile(filepath=str(fixture), load_ui=False)
    before = report()
    descriptor, temporary = tempfile.mkstemp(prefix="m16-pointcloud-reopen-", suffix=".blend", dir=fixture.parent)
    os.close(descriptor)
    try:
        bpy.ops.wm.save_as_mainfile(filepath=temporary, check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=temporary, load_ui=False)
        after = report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"point cloud save/reopen drift: {before} != {after}")
    value = {
        "schemaVersion": 1,
        "task": "M16-GAP-00019",
        "operation": "POINT_CLOUD_DATABLOCK_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "pointCloud": after,
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(value, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print(f"pointcloud-desktop-ok id={after['id']} points={after['pointCount']} saveReopen=exact")


if __name__ == "__main__":
    main()