#!/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 light_report():
    light = bpy.data.lights.get("WebGapLight")
    if light is None:
        raise RuntimeError("WebGapLight is missing")
    return {
        "id": "light:WebGapLight",
        "name": light.name,
        "lightType": {"POINT": 0, "SUN": 1, "SPOT": 2, "AREA": 4}[light.type],
        "color": [rounded(value) for value in light.color],
        "energy": rounded(light.energy),
        "exposure": rounded(light.exposure),
        "temperature": rounded(light.temperature),
        "useTemperature": bool(light.use_temperature),
        "castsShadow": bool(light.use_shadow),
        "radius": rounded(light.shadow_soft_size),
        "spotAngle": rounded(getattr(light, "spot_size", 0.785398)),
        "spotBlend": rounded(getattr(light, "spot_blend", 0.15)),
        "areaShape": {"POINT": 0, "DISK": 0, "RECTANGLE": 1, "ELLIPSE": 2}[light.shape] if light.type == "AREA" else 0,
        "areaSize": rounded(light.size),
        "areaSizeY": rounded(light.size_y),
        "areaSpread": rounded(light.spread),
        "sunAngle": rounded(getattr(light, "angle", 0.00918)),
    }


def main() -> None:
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --python check-light-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 = light_report()
    descriptor, temporary = tempfile.mkstemp(prefix="m16-light-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 = light_report()
    finally:
        pathlib.Path(temporary).unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"light save/reopen drift: {before} != {after}")
    report = {
        "schemaVersion": 1,
        "task": "M16-GAP-00012",
        "operation": "LIGHT_DATABLOCK_DESKTOP",
        "fixture": str(fixture),
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "light": 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"light-desktop-ok id={after['id']} type={after['lightType']} energy={after['energy']} saveReopen=exact")


if __name__ == "__main__":
    main()