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

import bpy


def render_state(render_path):
    scene = bpy.context.scene
    cube = bpy.data.objects.get("WBV2P5001RenderCube")
    camera = bpy.data.objects.get("WBV2P5001RenderCamera")
    receipt_text = bpy.data.texts.get("WBV2-P5-001-RenderRoutingReceipt")
    if cube is None or camera is None or receipt_text is None:
        raise RuntimeError("render routing fixture is missing cube, camera, or receipt")
    receipt = json.loads(receipt_text.as_string())
    scene.render.filepath = str(render_path)
    bpy.ops.render.render(write_still=True)
    image = bpy.data.images.load(str(render_path), check_existing=False)
    if tuple(image.size) != (64, 64):
        raise RuntimeError("render routing fixture did not produce a 64x64 image")
    pixels = image.pixels[:]
    rgba = bytes(max(0, min(255, round(float(value) * 255))) for value in pixels)
    visible = sum(1 for index in range(0, len(rgba), 4) if sum(rgba[index:index + 3]) > 12)
    result = {
        "sceneId": "scene:" + scene.name,
        "cubeId": "object:" + cube.name,
        "cameraId": "object:" + camera.name,
        "renderEngine": scene.render.engine,
        "resolution": [scene.render.resolution_x, scene.render.resolution_y, scene.render.resolution_percentage],
        "receipt": receipt,
        "pixelSha256": hashlib.sha256(rgba).hexdigest(),
        "pixelBytes": len(rgba),
        "visiblePixels": visible,
    }
    bpy.data.images.remove(image)
    return result


def main():
    arguments = sys.argv[sys.argv.index("--") + 1 :]
    if len(arguments) != 2:
        raise SystemExit("usage: blender -b --factory-startup --python check-wbv2-p5-001-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)
    render_path = fixture.with_name(f"{fixture.stem}-render.png")
    before = render_state(render_path)
    temporary = fixture.with_name(f"{fixture.stem}-reopen.blend")
    try:
        bpy.ops.wm.save_as_mainfile(filepath=str(temporary), check_existing=False, compress=True)
        bpy.ops.wm.open_mainfile(filepath=str(temporary), load_ui=False)
        after = render_state(render_path)
    finally:
        temporary.unlink(missing_ok=True)
        render_path.unlink(missing_ok=True)
    if before != after:
        raise RuntimeError(f"render routing save/reopen drift: {before} != {after}")
    report = {
        "schemaVersion": 1,
        "task": "WBV2-P5-001",
        "operation": "RENDER_ROUTING_DESKTOP",
        "fixtureSha256": hashlib.sha256(fixture.read_bytes()).hexdigest(),
        "state": 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("wbv2-p5-001-desktop-ok engine=%s pixels=%s visible=%d routes=%d saveReopen=exact" % (after["renderEngine"], after["pixelSha256"], after["visiblePixels"], len(after["receipt"]["routes"])))


if __name__ == "__main__":
    main()