"""The Grouper let down from BOARD (5.3 m) to POOL (9.3 m) through the deck well on the launch arm, read-only on
models/M_Ship_v2_interior_season2.blend (never saved); the Tiger's tg_descent_check.py, adopted from the Critique's run of 2026-10-22 (the docking arm's
build/scene_update_rig.check_descent does the same for the Kazah). The Grouper (checks/grouper_tris.npz, antenna folded) in
the place of _Tender1 at 9 steps, against the ship's meshes round the well (the carousel's own parts and the Tender instances left
out) and against arm 1's own parts. Also reads back the places and the handle the other checks assume.
blender -b ../M_Ship_v2_interior_season2.blend --python build/gr_descent_check.py   -> build/checks/descent.json"""
import bpy, os, math, json
import numpy as np
from mathutils import Vector
from mathutils.bvhtree import BVHTree
HERE = os.path.dirname(os.path.abspath(__file__))
VARIANT = os.environ.get("GR_VARIANT", "")
d = np.load(os.path.join(HERE, "checks", "grouper_tris%s.npz" % ("_raised" if VARIANT == "raised" else "")))
RV, RT, RN = d["v"], d["t"], d["names"]
D = bpy.data
rig = next(o for o in D.objects if o.name.startswith("DockArm_Rig") and o.type == 'ARMATURE')
h = rig.pose.bones["CTRL_Arm1_Hoist"]
info = {"hoist_y": round(h.location.y, 3), "reach_in": h.get("reach_in"), "tenders": {}}
for t in sorted([o for o in D.objects if o.name.startswith("_Tender")], key=lambda o: o.name):
    e = t.matrix_world.to_euler()
    info["tenders"][t.name] = {"origin": [round(c, 3) for c in t.matrix_world.translation],
                               "rot_deg": [round(math.degrees(a), 2) for a in e]}
BOARD, POOL = 5.3, 9.3
lo, hi = Vector((-10.5, -10.5, -11.5)), Vector((16.5, 2.5, 5.5))
skip = ("SK_DockArm_", "_Tender", "Carousel pylon", "DockArm_", "WGT_", "KIT |")
dg = bpy.context.evaluated_depsgraph_get()


def geo(o):
    e = o.evaluated_get(dg)
    me = e.to_mesh()
    me.calc_loop_triangles()
    M = e.matrix_world
    vs = [M @ v.co for v in me.vertices]
    ts = [tuple(t.vertices) for t in me.loop_triangles]
    e.to_mesh_clear()
    return vs, ts


ship = {}
for o in bpy.context.view_layer.objects:
    if o.type != 'MESH' or o.library is not None or o.name.startswith(skip) or o.hide_render or o.hide_viewport or not o.visible_get():
        continue
    if any(c.name.startswith(("90", "99", "GAME")) for c in o.users_collection) or any(k in o.name for k in ("_GAME", "_DOCK", "_LOD")):
        continue
    bb = [o.matrix_world @ Vector(c) for c in o.bound_box]
    if (max(v.x for v in bb) < lo.x or min(v.x for v in bb) > hi.x or max(v.y for v in bb) < lo.y or min(v.y for v in bb) > hi.y
            or max(v.z for v in bb) < lo.z or min(v.z for v in bb) > hi.z):
        continue
    vs, ts = geo(o)
    if ts:
        ship[o.name] = (BVHTree.FromPolygons(vs, ts), np.array([tuple(v) for v in vs]))
mine = [o for o in D.objects if o.name.startswith("SK_DockArm_Arm1_")]
tender = D.objects["_Tender1"]
y0 = h.location.y
rows = []
for i in range(9):
    y = BOARD + (POOL - BOARD) * i / 8
    h.location.y = y
    rig.update_tag()
    for o in mine:
        o.update_tag()
    tender.update_tag()
    bpy.context.view_layer.update()
    dg = bpy.context.evaluated_depsgraph_get()
    M = np.array(tender.matrix_world)
    w = RV @ M[:3, :3].T + M[:3, 3]
    ttree = BVHTree.FromPolygons([Vector(p) for p in w], [tuple(int(k) for k in t) for t in RT])
    lo_t, hi_t = w.min(0) - 1.0, w.max(0) + 1.0
    cross, gap, near = [], 99.0, None
    for sn, (st, sv) in ship.items():
        n = len(ttree.overlap(st))
        if n:
            cross.append((sn, n))
        sel = np.all((sv > lo_t) & (sv < hi_t), axis=1)
        for v in sv[sel][::2]:
            dd = ttree.find_nearest(Vector(v))[3]
            if dd < gap:
                gap, near = dd, sn
    arm_hits, arm_gap = [], 99.0
    for o in mine:
        vs, ts = geo(o)
        if not ts:
            continue
        if ttree.overlap(BVHTree.FromPolygons(vs, ts)):
            arm_hits.append(o.name)
        arm_gap = min(arm_gap, min(ttree.find_nearest(p)[3] for p in vs))
    rows.append(dict(lowered=round(y, 2), tender_origin=[round(c, 3) for c in tender.matrix_world.translation],
                     grouper_z_range=[round(float(w[:, 2].min()), 3), round(float(w[:, 2].max()), 3)],
                     ship_crossings=cross, ship_least_gap=round(gap, 3), nearest_ship=near, arm_hits=arm_hits,
                     arm_least_gap=round(arm_gap, 4)))
h.location.y = y0
rig.update_tag()
bpy.context.view_layer.update()
summary = {"steps": len(rows), "ship_meshes": len(ship), "with_ship_crossings": sum(1 for r in rows if r["ship_crossings"]),
           "least_ship_gap_m": min(r["ship_least_gap"] for r in rows),
           "nearest_ship": min(rows, key=lambda r: r["ship_least_gap"])["nearest_ship"],
           "with_arm_hits": sum(1 for r in rows if r["arm_hits"]), "least_arm_gap_m": min(r["arm_least_gap"] for r in rows)}
json.dump({"summary": summary, "ship_state": info, "steps": rows}, open(os.path.join(HERE, "checks", "descent%s.json" % ("_raised" if VARIANT == "raised" else "")), "w"), indent=1)
print("DESCENT", json.dumps(summary), json.dumps(info))