#!/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.metaballs.get("WebGapMetaBall")
    if data is None:
        raise RuntimeError("WebGapMetaBall is missing")
    return {
        "id": "metaball:WebGapMetaBall",
        "name": data.name,
        "resolution": rounded(data.resolution),
        "renderResolution": rounded(data.render_resolution),
        "pointCount": len(data.elements),
        "elements": [{"position": [rounded(v) for v in item.co], "radius": rounded(item.radius), "scale": [rounded(item.size_x), rounded(item.size_y), rounded(item.size_z)]} for item in data.elements],
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-metaball-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-metaball-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"metaball save/reopen drift: {before} != {after}")
    value = {"schemaVersion": 1, "task": "M16-GAP-00015", "operation": "METABALL_DATABLOCK_DESKTOP", "fixture": str(fixture), "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(), "metaball": 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"metaball-desktop-ok id={after['id']} points={after['pointCount']} saveReopen=exact")


if __name__ == "__main__":
    main()