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#!/usr/bin/env python3
"""Isaac Lab replay of v2d G1 Inspire + object + MANO.

Scene: a table, the tracked object as a dynamic box, and the floating Inspire
hand. Predicted object motion is not assumed to already sit on the table, so
replay has two phases:

1. **Settle (physics)** — XY of the object is locked to the video start;
   gravity may change Z and rotation until the object rests on the table.
   The hand (and MANO) keep the same relative pose to the object as in the
   video at t=0.
2. **Motion** — remaining clip is applied as a rigid delta from that settled
   start, so hand–object relative motion matches the video.

Plays once, writes an MP4, then exits.

Usage (from simulation/):

  ./replay_v2d.sh --npz ../reconstruction/runs/<seq>/obj_tracking_out/isaaclab_replay.npz --headless
"""

from __future__ import annotations

import argparse
import sys
from pathlib import Path

from isaaclab.app import AppLauncher

if hasattr(sys.stdout, "reconfigure"):
    sys.stdout.reconfigure(line_buffering=True)

parser = argparse.ArgumentParser(description="Replay v2d G1 Inspire + object + MANO in Isaac Lab.")
parser.add_argument("--npz", type=Path, required=True, help="isaaclab_replay.npz from retarget/export_isaaclab.py")
parser.add_argument(
    "--output",
    type=Path,
    default=None,
    help="MP4 path (default: <npz-dir>/isaaclab_replay.mp4)",
)
parser.add_argument("--no-mano", action="store_true")
parser.add_argument("--no-object", action="store_true")
parser.add_argument("--table-z", type=float, default=0.75, help="Table-top height (m).")
parser.add_argument("--drop-height", type=float, default=0.08, help="Object origin above table at settle start (m).")
parser.add_argument("--settle-sec", type=float, default=2.0, help="Physics settle duration (s).")
parser.add_argument("--no-settle", action="store_true", help="Skip physics settle; play video poses on the table.")
AppLauncher.add_app_launcher_args(parser)
args_cli = parser.parse_args()
args_cli.enable_cameras = True

app_launcher = AppLauncher(args_cli)
simulation_app = app_launcher.app

import numpy as np  # noqa: E402
import torch  # noqa: E402

import isaaclab.sim as sim_utils  # noqa: E402
from isaaclab.actuators import ImplicitActuatorCfg  # noqa: E402
from isaaclab.assets import Articulation, ArticulationCfg, RigidObject, RigidObjectCfg  # noqa: E402
from isaaclab.markers import VisualizationMarkers, VisualizationMarkersCfg  # noqa: E402
from isaaclab.sensors.camera import Camera, CameraCfg  # noqa: E402
from isaaclab.sim import SimulationContext  # noqa: E402

_NONE_DRIVE = sim_utils.UrdfConverterCfg.JointDriveCfg(
    gains=sim_utils.UrdfConverterCfg.JointDriveCfg.PDGainsCfg(stiffness=0.0, damping=0.0)
)
_TABLE_SIZE = (1.6, 1.0, 0.05)


def _wxyz_to_xyzw(wxyz: np.ndarray) -> np.ndarray:
    wxyz = np.asarray(wxyz, dtype=np.float64)
    return np.stack([wxyz[..., 1], wxyz[..., 2], wxyz[..., 3], wxyz[..., 0]], axis=-1)


def _pose7_xyzw(pos: np.ndarray, wxyz: np.ndarray) -> np.ndarray:
    return np.concatenate([np.asarray(pos, dtype=np.float64), _wxyz_to_xyzw(wxyz)], axis=-1)


def _quat_mul(q1: np.ndarray, q2: np.ndarray) -> np.ndarray:
    x1, y1, z1, w1 = np.asarray(q1, dtype=np.float64)
    x2, y2, z2, w2 = np.asarray(q2, dtype=np.float64)
    return np.array(
        [
            w1 * x2 + x1 * w2 + y1 * z2 - z1 * y2,
            w1 * y2 - x1 * z2 + y1 * w2 + z1 * x2,
            w1 * z2 + x1 * y2 - y1 * x2 + z1 * w2,
            w1 * w2 - x1 * x2 - y1 * y2 - z1 * z2,
        ]
    )


def _quat_conj(q: np.ndarray) -> np.ndarray:
    return np.array([-q[0], -q[1], -q[2], q[3]], dtype=np.float64)


def _quat_apply(q: np.ndarray, v: np.ndarray) -> np.ndarray:
    v = np.asarray(v, dtype=np.float64)
    qv = np.array([v[0], v[1], v[2], 0.0])
    return _quat_mul(_quat_mul(q, qv), _quat_conj(q))[:3]


def _compose(a: np.ndarray, b: np.ndarray) -> np.ndarray:
    """SE3 multiply pose7 xyz+xyzw: a * b."""
    pa, qa = a[:3], a[3:]
    pb, qb = b[:3], b[3:]
    out = np.empty(7, dtype=np.float64)
    out[:3] = pa + _quat_apply(qa, pb)
    out[3:] = _quat_mul(qa, qb)
    return out


def _inverse(a: np.ndarray) -> np.ndarray:
    q = _quat_conj(a[3:])
    out = np.empty(7, dtype=np.float64)
    out[:3] = -_quat_apply(q, a[:3])
    out[3:] = q
    return out


def _apply_pose_pts(pose: np.ndarray, pts: np.ndarray) -> np.ndarray:
    p, q = pose[:3], pose[3:]
    pts = np.asarray(pts, dtype=np.float64)
    flat = pts.reshape(-1, 3)
    out = np.empty_like(flat)
    for i, v in enumerate(flat):
        out[i] = p + _quat_apply(q, v)
    return out.reshape(pts.shape)


def _hand_cfg(urdf: str, prim: str) -> ArticulationCfg:
    return ArticulationCfg(
        prim_path=prim,
        spawn=sim_utils.UrdfFileCfg(
            asset_path=urdf,
            fix_base=False,
            activate_contact_sensors=False,
            merge_fixed_joints=True,
            rigid_props=sim_utils.RigidBodyPropertiesCfg(
                disable_gravity=True,
                linear_damping=0.0,
                angular_damping=0.0,
                max_linear_velocity=1000.0,
                max_angular_velocity=1000.0,
            ),
            collision_props=sim_utils.CollisionPropertiesCfg(collision_enabled=False),
            articulation_props=sim_utils.ArticulationRootPropertiesCfg(
                enabled_self_collisions=False,
                solver_position_iteration_count=8,
                solver_velocity_iteration_count=0,
            ),
            joint_drive=_NONE_DRIVE,
        ),
        init_state=ArticulationCfg.InitialStateCfg(
            pos=(0.0, 0.0, 0.5),
            joint_pos={".*": 0.0},
            joint_vel={".*": 0.0},
        ),
        actuators={
            "fingers": ImplicitActuatorCfg(
                joint_names_expr=[".*"],
                stiffness=0.0,
                damping=0.0,
                effort_limit_sim=10.0,
                velocity_limit_sim=10.0,
            ),
        },
    )


def _object_cfg(urdf: str, prim: str, *, physics: bool) -> RigidObjectCfg:
    return RigidObjectCfg(
        prim_path=prim,
        spawn=sim_utils.UrdfFileCfg(
            asset_path=urdf,
            fix_base=False,
            joint_drive=None,
            mass_props=sim_utils.MassPropertiesCfg(mass=0.35),
            rigid_props=sim_utils.RigidBodyPropertiesCfg(
                disable_gravity=not physics,
                kinematic_enabled=not physics,
                linear_damping=0.15 if physics else 0.0,
                angular_damping=0.35 if physics else 0.0,
                max_linear_velocity=5.0,
                max_angular_velocity=20.0,
            ),
            collision_props=sim_utils.CollisionPropertiesCfg(collision_enabled=physics),
            physics_material=sim_utils.RigidBodyMaterialCfg(
                static_friction=0.8, dynamic_friction=0.6, restitution=0.0
            ),
        ),
        init_state=RigidObjectCfg.InitialStateCfg(pos=(0.0, 0.0, 0.5)),
    )


def _spawn_table(xy: np.ndarray, table_top: float) -> None:
    thick = _TABLE_SIZE[2]
    cfg = sim_utils.CuboidCfg(
        size=_TABLE_SIZE,
        rigid_props=sim_utils.RigidBodyPropertiesCfg(
            kinematic_enabled=True,
            disable_gravity=True,
        ),
        mass_props=sim_utils.MassPropertiesCfg(mass=50.0),
        collision_props=sim_utils.CollisionPropertiesCfg(),
        visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.48, 0.34, 0.22)),
        physics_material=sim_utils.RigidBodyMaterialCfg(
            static_friction=0.9, dynamic_friction=0.7, restitution=0.0
        ),
    )
    cfg.func(
        "/World/Table",
        cfg,
        translation=(float(xy[0]), float(xy[1]), float(table_top - 0.5 * thick)),
    )


def _joint_order(sim_names: list[str], src_names: list[str]) -> list[int | None]:
    src = {n: i for i, n in enumerate(src_names)}
    order: list[int | None] = [src.get(name) for name in sim_names]
    matched = sum(i is not None for i in order)
    missing = [n for n, i in zip(sim_names, order) if i is None]
    extra = [n for n in src_names if n not in set(sim_names)]
    print(f"[v2d] joint map: {matched}/{len(sim_names)} sim joints in retarget q", flush=True)
    if missing:
        print(f"[v2d] sim joints not in npz (held at 0, often mimics): {missing}", flush=True)
    if extra:
        print(f"[v2d] retarget joints unused by sim (often mimics): {extra}", flush=True)
    if matched == 0:
        raise RuntimeError(f"no joint-name overlap: sim={sim_names} retarget={src_names}")
    return order


def _finger_row(finger_q: np.ndarray, t: int, order: list[int | None]) -> np.ndarray:
    row = np.zeros(len(order), dtype=np.float64)
    src = finger_q[t]
    for j, idx in enumerate(order):
        if idx is not None and idx < src.shape[0] and np.isfinite(src[idx]):
            row[j] = src[idx]
    return row


def _as_numpy(x) -> np.ndarray:
    if hasattr(x, "torch"):
        x = x.torch
    if isinstance(x, torch.Tensor):
        return x.detach().cpu().numpy()
    return np.asarray(x)


def _rgb_frame(camera: Camera) -> np.ndarray:
    out = camera.data.output
    rgb = out["rgb"] if isinstance(out, dict) or hasattr(out, "__getitem__") else out
    img = _as_numpy(rgb)
    if img.ndim == 4:
        img = img[0]
    img = img[..., :3]
    if img.dtype != np.uint8:
        scale = 255.0 if float(np.nanmax(img)) <= 1.5 else 1.0
        img = np.clip(img * scale, 0, 255).astype(np.uint8)
    h, w = img.shape[:2]
    return img[: h - (h % 2), : w - (w % 2)]


def _write_mp4(path: Path, frames: list[np.ndarray], fps: float) -> None:
    if not frames:
        raise RuntimeError("no frames captured for MP4")
    path.parent.mkdir(parents=True, exist_ok=True)
    try:
        import imageio.v2 as imageio

        imageio.mimsave(str(path), frames, fps=float(fps), codec="libx264", pixelformat="yuv420p")
        return
    except Exception as exc:
        print(f"[v2d] imageio h264 failed ({exc}); trying OpenCV", flush=True)
    import cv2

    h, w = frames[0].shape[:2]
    writer = cv2.VideoWriter(str(path), cv2.VideoWriter_fourcc(*"mp4v"), float(fps), (w, h))
    if not writer.isOpened():
        raise RuntimeError(f"could not open VideoWriter for {path}")
    for fr in frames:
        writer.write(cv2.cvtColor(fr, cv2.COLOR_RGB2BGR))
    writer.release()


def main() -> None:
    npz_path = args_cli.npz.resolve()
    if not npz_path.is_file():
        raise SystemExit(f"missing {npz_path} — run retarget/export_isaaclab.sh first")
    out_mp4 = (args_cli.output or (npz_path.parent / "isaaclab_replay.mp4")).resolve()
    data = np.load(npz_path, allow_pickle=True)
    fps = float(data["fps"])
    n = int(data["root_pos"].shape[0])
    side = str(data["side"])
    hand_urdf = str(data["hand_urdf"])
    obj_urdf = str(data["object_urdf"]) if "object_urdf" in data else ""
    finger_names = [str(x) for x in np.atleast_1d(data["finger_joint_names"]).tolist()]
    root_pose = _pose7_xyzw(data["root_pos"], data["root_wxyz"])
    finger_q = np.asarray(data["finger_q"], dtype=np.float64)
    obj_pose = None
    if (
        not args_cli.no_object
        and obj_urdf
        and Path(obj_urdf).is_file()
        and np.isfinite(data["object_pos"]).any()
    ):
        obj_pose = _pose7_xyzw(data["object_pos"], data["object_wxyz"])
    mano = None if args_cli.no_mano else np.asarray(data["mano_joints"], dtype=np.float64)

    table_top = float(args_cli.table_z)
    drop = float(args_cli.drop_height)
    if obj_pose is not None:
        z_shift = table_top + drop - float(obj_pose[0, 2])
        obj_pose = obj_pose.copy()
        obj_pose[:, 2] += z_shift
        root_pose = root_pose.copy()
        root_pose[:, 2] += z_shift
        if mano is not None:
            mano = mano.copy()
            mano[:, :, 2] += z_shift
        xy0 = obj_pose[0, :2].copy()
    else:
        z_shift = 0.0
        xy0 = root_pose[0, :2].copy()

    print(f"[v2d] {n} frames @ {fps} fps  side={side}", flush=True)
    print(f"[v2d] table top z={table_top:.3f} m  z_shift={z_shift:.3f} m  xy=({xy0[0]:.3f}, {xy0[1]:.3f})", flush=True)
    print(f"[v2d] hand {hand_urdf}", flush=True)
    if obj_pose is not None:
        print(f"[v2d] object {obj_urdf}", flush=True)
    print(f"[v2d] mp4 {out_mp4}", flush=True)

    sim_dt = 1.0 / 60.0
    sim_cfg = sim_utils.SimulationCfg(dt=sim_dt, device=args_cli.device)
    sim = SimulationContext(sim_cfg)
    look = np.array([xy0[0], xy0[1], table_top + 0.15], dtype=np.float32)
    eye = np.array([look[0] + 1.15, look[1] - 1.15, look[2] + 0.75], dtype=np.float32)
    sim.set_camera_view(eye=eye.tolist(), target=look.tolist())

    ground_cfg = sim_utils.GroundPlaneCfg()
    ground_cfg.func("/World/defaultGroundPlane", ground_cfg)
    light_cfg = sim_utils.DomeLightCfg(intensity=2500.0, color=(0.8, 0.8, 0.8))
    light_cfg.func("/World/Light", light_cfg)
    _spawn_table(xy0, table_top)

    do_physics = obj_pose is not None and not args_cli.no_settle
    hand = Articulation(_hand_cfg(hand_urdf, "/World/G1Inspire"))
    obj = None
    if obj_pose is not None:
        obj = RigidObject(_object_cfg(obj_urdf, "/World/Object", physics=do_physics))
    mano_markers = None
    if mano is not None:
        mano_markers = VisualizationMarkers(
            VisualizationMarkersCfg(
                prim_path="/World/Visuals/mano",
                markers={
                    "joint": sim_utils.SphereCfg(
                        radius=0.008,
                        visual_material=sim_utils.PreviewSurfaceCfg(diffuse_color=(0.15, 0.85, 0.35)),
                    ),
                },
            )
        )
    camera = Camera(
        CameraCfg(
            prim_path="/World/RecordCamera",
            update_period=0.0,
            height=480,
            width=640,
            data_types=["rgb"],
            spawn=sim_utils.PinholeCameraCfg(
                focal_length=24.0,
                focus_distance=400.0,
                horizontal_aperture=20.955,
                clipping_range=(0.1, 1.0e5),
            ),
        )
    )

    sim.reset()
    camera.set_world_poses_from_view(
        torch.tensor(eye, device=sim.device).unsqueeze(0),
        torch.tensor(look, device=sim.device).unsqueeze(0),
    )
    sim_names = list(hand.joint_names)
    print(f"[v2d] sim joints ({len(sim_names)}): {sim_names}", flush=True)
    order = _joint_order(sim_names, finger_names)
    device = sim.device
    zeros6 = torch.zeros(1, 6, device=device)

    def _write_hand(pose7: np.ndarray, t_fingers: int) -> None:
        rp = torch.tensor(pose7, dtype=torch.float32, device=device).unsqueeze(0)
        if torch.isfinite(rp).all():
            hand.write_root_pose_to_sim_index(root_pose=rp)
            hand.write_root_velocity_to_sim_index(root_velocity=zeros6)
            jq = torch.tensor(_finger_row(finger_q, t_fingers, order), dtype=torch.float32, device=device).unsqueeze(0)
            hand.write_joint_state_to_sim_index(position=jq, velocity=torch.zeros_like(jq))
        hand.write_data_to_sim()

    def _write_obj(pose7: np.ndarray) -> None:
        if obj is None:
            return
        op = torch.tensor(pose7, dtype=torch.float32, device=device).unsqueeze(0)
        obj.write_root_pose_to_sim_index(root_pose=op)
        obj.write_root_velocity_to_sim_index(root_velocity=zeros6)
        obj.write_data_to_sim()

    def _write_mano_from_world(pts: np.ndarray) -> None:
        if mano_markers is None:
            return
        if np.isfinite(pts).all():
            mano_markers.visualize(translations=pts)

    def _lock_object_xy(pose7: np.ndarray) -> np.ndarray:
        out = pose7.copy()
        out[0] = xy0[0]
        out[1] = xy0[1]
        return out

    def _read_obj_pose() -> np.ndarray:
        return _as_numpy(obj.data.root_link_pose_w).reshape(-1)[:7].astype(np.float64)

    def _read_obj_vel() -> np.ndarray:
        return _as_numpy(obj.data.root_link_vel_w).reshape(-1)[:6].astype(np.float64)

    def _step_sim() -> None:
        sim.step()
        hand.update(sim_dt)
        if obj is not None:
            obj.update(sim_dt)
        camera.update(sim_dt)

    t0_obj = obj_pose[0].copy() if obj_pose is not None else None
    t0_hand = root_pose[0].copy()
    t0_mano = mano[0].copy() if mano is not None else None
    rel_hand = _compose(_inverse(t0_obj), t0_hand) if t0_obj is not None else None

    frames: list[np.ndarray] = []
    capture_every = max(1, int(round((1.0 / max(fps, 1e-3)) / sim_dt)))

    def _maybe_capture(step_i: int, force: bool = False) -> None:
        if force or step_i % capture_every == 0:
            frames.append(_rgb_frame(camera))

    # Camera warmup.
    if obj_pose is not None:
        _write_obj(obj_pose[0])
    _write_hand(root_pose[0], 0)
    if mano is not None:
        _write_mano_from_world(mano[0])
    for _ in range(4):
        _step_sim()

    settled = t0_obj.copy() if t0_obj is not None else None
    if do_physics:
        n_settle = max(1, int(round(float(args_cli.settle_sec) / sim_dt)))
        print(f"[v2d] settle {n_settle} steps ({args_cli.settle_sec:.2f}s), XY locked, Z/rot free", flush=True)
        _write_obj(_lock_object_xy(obj_pose[0]))
        for s in range(n_settle):
            if not simulation_app.is_running():
                break
            _step_sim()
            pose = _lock_object_xy(_read_obj_pose())
            vel = _read_obj_vel()
            vel[0] = 0.0
            vel[1] = 0.0
            op = torch.tensor(pose, dtype=torch.float32, device=device).unsqueeze(0)
            ov = torch.tensor(vel, dtype=torch.float32, device=device).unsqueeze(0)
            obj.write_root_pose_to_sim_index(root_pose=op)
            obj.write_root_velocity_to_sim_index(root_velocity=ov)
            obj.write_data_to_sim()
            obj.update(0.0)
            pose = _lock_object_xy(_read_obj_pose())
            _write_hand(_compose(pose, rel_hand), 0)
            if t0_mano is not None:
                delta = _compose(pose, _inverse(t0_obj))
                _write_mano_from_world(_apply_pose_pts(delta, t0_mano))
            _maybe_capture(s)
            if s % 30 == 0:
                print(
                    f"  settle {s}/{n_settle}  z={pose[2]:.3f}  |v|={np.linalg.norm(vel[:3]):.3f}",
                    flush=True,
                )
        settled = _lock_object_xy(_read_obj_pose())
        print(
            f"[v2d] settled z={settled[2]:.3f} m  (video start z={t0_obj[2]:.3f} m)",
            flush=True,
        )

    delta = np.array([0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0], dtype=np.float64)
    if settled is not None and t0_obj is not None:
        delta = _compose(settled, _inverse(t0_obj))
        # After settle, drive both bodies kinematically so the clip cannot fight gravity.
        _write_obj(settled)

    print(f"[v2d] motion {n} frames", flush=True)
    for t in range(n):
        if not simulation_app.is_running():
            break
        if obj_pose is not None:
            _write_obj(_compose(delta, obj_pose[t]))
        _write_hand(_compose(delta, root_pose[t]), t)
        if mano is not None:
            _write_mano_from_world(_apply_pose_pts(delta, mano[t]))
        _step_sim()
        _maybe_capture(t, force=(t == n - 1))
        if t % 10 == 0 or t == n - 1:
            print(f"  motion {t + 1}/{n}", flush=True)

    _write_mp4(out_mp4, frames, fps)
    print(f"[v2d] wrote {out_mp4} ({len(frames)} frames)", flush=True)


if __name__ == "__main__":
    main()
    simulation_app.close()