#!/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 settings_report():
    settings = bpy.data.particles.get("WebGapParticleSettings")
    if settings is None:
        raise RuntimeError("WebGapParticleSettings is missing")
    return {
        "id": "particle-settings:" + settings.name,
        "name": settings.name,
        "type": int({"EMITTER": 0, "HAIR": 1}.get(settings.type, -1)),
        "from": int({"FACE": 0, "VERT": 1, "VOLUME": 2}.get(settings.emit_from, -1)),
        "distribution": int({"JIT": 0, "RAND": 1, "GRID": 2}.get(settings.distribution, -1)),
        "physicsType": int({"NEWTON": 0, "KEYED": 1, "BOIDS": 2, "NO": 3}.get(settings.physics_type, -1)),
        "totalParticles": int(settings.count),
        "start": rounded(settings.frame_start),
        "end": rounded(settings.frame_end),
        "lifetime": rounded(settings.lifetime),
        "size": rounded(settings.particle_size),
        "drawSize": rounded(settings.display_size),
    }


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-particle-settings-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 = settings_report()
    descriptor, temporary = tempfile.mkstemp(prefix="m16-particle-settings-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 = settings_report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"particle settings save/reopen drift: {before} != {after}")
    report = {
        "schemaVersion": 1,
        "task": "M16-GAP-00018",
        "operation": "PARTICLE_SETTINGS_DATABLOCK_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "particleSettings": after,
        "saveReopen": "EXACT",
        "blenderVersion": bpy.app.version_string,
    }
    output.parent.mkdir(parents=True, exist_ok=True)
    output.write_text(json.dumps(report, indent=2, sort_keys=True) + "\n", encoding="utf-8")
    print(f"particle-settings-desktop-ok id={after['id']} count={after['totalParticles']} saveReopen=exact")


if __name__ == "__main__":
    main()