"""Background plate: the same cameras, the same lighting, no object.

In simulation this gives an EXACT object mask by image difference, which beats every
height-threshold heuristic - and the height threshold is precisely what failed: CREStereo
puts the belt a few mm above belt_z, so a z-crop returns a belt patch whose footprint is
the crop window (measured 1700x1550x64 mm for every item, i.e. the crop, not the object).
"""
import json, os, sys
REPO = "/home/dasha/robozon-sorter"
for e in (REPO, f"{REPO}/control_test"):
    if e not in sys.path:
        sys.path.insert(0, e)
for _m in [k for k in list(sys.modules) if k.startswith("cam_configs")]:
    del sys.modules[_m]
import importlib; importlib.invalidate_caches()

import asyncio
import omni.usd, omni.timeline
import omni.kit.viewport.utility as vp
import isaacsim.core.experimental.utils.app as app_utils
from pxr import UsdGeom

import cam_configs as CC

CFG = globals().get("cfg", CC.DEFAULT)
OUT = f"{REPO}/control_test/captures/{CFG}"
os.makedirs(OUT, exist_ok=True)

stage = omni.usd.get_context().get_stage()
tl = omni.timeline.get_timeline_interface()
if tl.is_playing():
    tl.stop(); await app_utils.update_app_async(steps=10)

calib = CC.apply_config(stage, CFG)
root = stage.GetPrimAtPath("/World/CapItems")
if root.IsValid():
    for c in root.GetChildren():
        UsdGeom.Imageable(c).MakeInvisible()
await app_utils.update_app_async(steps=25)

w = vp.get_active_viewport()
orig = w.camera_path
bg = {}
for cam_name in calib:
    w.camera_path = CC._cam(stage, cam_name).GetPath()
    await app_utils.update_app_async(steps=22)
    await asyncio.sleep(0)
    f = f"{OUT}/__background__{cam_name}.png"
    vp.capture_viewport_to_file(w, file_path=f)
    await app_utils.update_app_async(steps=12)
    await asyncio.sleep(0)
    bg[cam_name] = f
w.camera_path = orig
await app_utils.update_app_async(steps=10)

man_path = f"{OUT}/manifest.json"
man = json.load(open(man_path))
man["background"] = bg
json.dump(man, open(man_path, "w"), indent=1)
print(f"background plate: {len(bg)} views -> {man_path}")