"""Bring the docking arm's new surfaces into a scene that already holds the RIGGED carousel, in place.
(The round of 2026-10-13. Since the boom joint of 2026-10-16 the rig itself differs: use scene_update_rig.py for that;
 pylon_uvs() here is still what gives the ship's pylon the two UV layers the arm's materials read.)

Written for the vessel interior (models/M_Ship_v2_interior_season2.blend), where the "Main vessel interior layout"
session swapped the rigged carousel in on 2026-10-13 and gave its rig the reach_in motion. That file is edited by hand
and by that session, so nothing is rebuilt or reloaded: the armature, its pose, its drivers and constraints, the 26
SK_DockArm_* objects, their modifiers and vertex groups stay exactly as they are. Only this changes:
  * each object's MESH datablock is replaced by the one of the same name from DockArm_Carousel_Rigged.blend
    (two UV layers, the light lines gone, the hose bands with their own material);
  * the M_DockArm_* MATERIAL datablocks are replaced by the textured ones under the same names, so anything else that
    uses them follows (the interior's carousel pylon borrows Paint, Graphite and Steel);
  * images: the scene's own datablock is used wherever it already has the same file in the same colour space;
    the two old hose maps are removed with the old hose material;
  * the pylon gets the two UV layers these materials read (added beside its own; nothing of it is changed).

    exec(open(r"...\\docking-arm\\build\\scene_update_surfaces.py").read());  result = update_surfaces()

The geometry is checked against the scene's own state before the change (the hoses vertex by vertex, the rigid parts
by their bounds); on a mismatch it raises AFTER having changed the scene, so run it on a copy first.
"""
import bpy, os, math
from mathutils import Vector

_SRC = r"D:\HADAL - The Descent\models\docking-arm\DockArm_Carousel_Rigged.blend"      # written out: this file is exec'd, so it has no __file__ of its own
PYLON = "Carousel pylon (bay roof to mount flange)"

def _world(o):
    e = o.evaluated_get(bpy.context.evaluated_depsgraph_get())
    M = e.matrix_world.copy()
    return [M @ v.co for v in e.data.vertices]

def _bounds(vs):
    return [min(v[i] for v in vs) for i in range(3)] + [max(v[i] for v in vs) for i in range(3)]

def _path(im):
    return os.path.normcase(os.path.normpath(bpy.path.abspath(im.filepath))) if im.filepath else ""

def pylon_uvs(ob):
    """UV_Tile (metres: walls unrolled, flat rings as seen from above) and UVMap (a blank corner of the arm's atlas: no
    baked edges or crevices there) beside the pylon's own layer, which stays the active one."""
    me = ob.data
    if "UV_Tile" in me.uv_layers and "UVMap" in me.uv_layers:
        return False
    own = [tuple(d.uv) for d in me.uv_layers[0].data] if len(me.uv_layers) else None
    keep_active = me.uv_layers.active.name if me.uv_layers.active else None
    keep_render = next((l.name for l in me.uv_layers if l.active_render), None)
    for n in ("UV_Tile", "UVMap"):
        if n not in me.uv_layers:
            me.uv_layers.new(name=n, do_init=False)
    tl, at = me.uv_layers["UV_Tile"].data, me.uv_layers["UVMap"].data
    for p in me.polygons:
        cs = [me.vertices[vi].co for vi in p.vertices]
        if abs(p.normal.z) > 0.7:
            uv = [(c.x, c.y) for c in cs]
        else:
            ca = math.atan2(p.center.y, p.center.x)
            r = sum(math.hypot(c.x, c.y) for c in cs) / len(cs)
            uv = [((ca + (math.atan2(c.y, c.x) - ca + math.pi) % (2 * math.pi) - math.pi) * r, c.z) for c in cs]
        for li, t in zip(p.loop_indices, uv):
            tl[li].uv = t
            at[li].uv = (0.85 + 0.10 * (own[li][0] % 1.0), 0.85 + 0.10 * (own[li][1] % 1.0)) if own else (0.90, 0.90)
    if keep_active:
        me.uv_layers.active = me.uv_layers[keep_active]
    if keep_render:
        me.uv_layers[keep_render].active_render = True
    return True

def update_surfaces(src=_SRC):
    D = bpy.data
    if bpy.context.mode != 'OBJECT':
        raise RuntimeError("the scene is in %s mode; nothing was changed" % bpy.context.mode)
    objs = sorted((o for o in D.objects if o.type == 'MESH' and o.name.startswith("SK_DockArm_")), key=lambda o: o.name)
    if len(objs) != 26:
        raise RuntimeError("expected the 26 SK_DockArm_ objects of the rigged carousel, found %d; nothing was changed" % len(objs))
    if any(o.data.users != 1 for o in objs) or any(s.link != 'DATA' for o in objs for s in o.material_slots):
        raise RuntimeError("a carousel mesh is shared or has object-linked material slots; nothing was changed")
    if any("UV_Tile" in o.data.uv_layers for o in objs):
        raise RuntimeError("the carousel here already has the new meshes; nothing was changed")
    wanted = [o.data.name for o in objs]
    before = {o.name: _world(o) for o in objs}
    old_mats = {m.name: m for m in D.materials if m.name.startswith("M_DockArm_")}
    mats_before = {m.as_pointer() for m in D.materials}
    imgs_before = {i.as_pointer() for i in D.images}
    with D.libraries.load(src, link=False) as (s, t):
        missing = [n for n in wanted if n not in s.meshes]
        if missing:
            raise RuntimeError("not in %s: %s; nothing was changed" % (os.path.basename(src), missing))
        t.meshes = list(wanted)
    new = dict(zip(wanted, t.meshes))
    rep = dict(source=src, meshes=0, materials_replaced=[], materials_added=[], images_reused=[], images_added=[], images_removed=[])
    # images first: the scene's own datablock wherever it is the same file read the same way
    have = {}
    for i in D.images:
        if i.as_pointer() in imgs_before and i.filepath:
            have.setdefault((_path(i), i.colorspace_settings.name, i.alpha_mode), i)
    for i in [i for i in D.images if i.as_pointer() not in imgs_before]:
        twin = have.get((_path(i), i.colorspace_settings.name, i.alpha_mode))
        if twin is not None:
            i.user_remap(twin)
            rep["images_reused"].append(twin.name)
            D.images.remove(i)
        else:
            if not os.path.isfile(bpy.path.abspath(i.filepath)):
                raise RuntimeError("texture not found: %s" % i.filepath)
            if not i.filepath.startswith("//") and D.filepath:
                i.filepath = bpy.path.relpath(bpy.path.abspath(i.filepath))
            rep["images_added"].append(i.name + "  " + i.filepath)
    # meshes: same objects, new data
    for o in objs:
        old, nm = o.data, o.data.name
        me = new[nm]
        old.user_remap(me)
        D.meshes.remove(old)
        me.name = nm
        rep["meshes"] += 1
    # materials: same names, new trees; other users of the old ones (the pylon) follow
    for m in [m for m in D.materials if m.as_pointer() not in mats_before]:
        base = m.name[:-4] if len(m.name) > 4 and m.name[-4] == "." and m.name[-3:].isdigit() else m.name
        old = old_mats.get(base)
        if old is not None:
            old.user_remap(m)
            D.materials.remove(old)
            m.name = base
            rep["materials_replaced"].append(base)
        else:
            rep["materials_added"].append(m.name)
    for i in [i for i in D.images if i.name.startswith(("T_DockArm_HoseFold_Mask", "T_DockArm_HoseWrinkle_Normal")) and i.users == 0]:
        rep["images_removed"].append(i.name)
        D.images.remove(i)
    py = D.objects.get(PYLON)
    rep["pylon_uvs_added"] = bool(py and py.type == 'MESH' and pylon_uvs(py))
    # the same carousel as before?
    bpy.context.view_layer.update()
    worst_hose, worst_box = 0.0, 0.0
    for o in objs:
        a, b = before[o.name], _world(o)
        if "OreHose" in o.name:
            if len(a) != len(b):
                raise RuntimeError("%s: vertex count changed %d -> %d" % (o.name, len(a), len(b)))
            worst_hose = max(worst_hose, max((p - q).length for p, q in zip(a, b)))
        else:
            worst_box = max(worst_box, max(abs(x - y) for x, y in zip(_bounds(a), _bounds(b))))
    rep["hose_vertices_moved_m"] = round(worst_hose, 7)
    rep["part_bounds_moved_m"] = round(worst_box, 7)
    rep["uv_layers"] = sorted({tuple(l.name for l in o.data.uv_layers) for o in objs})
    rep["materials_now"] = sorted(m.name for m in D.materials if m.name.startswith("M_DockArm_"))
    rep["images_missing"] = sorted(i.name for i in D.images if i.name.startswith("T_DockArm_") and i.source == 'FILE' and not i.packed_file
                                   and not os.path.isfile(bpy.path.abspath(i.filepath)))
    if worst_hose > 1e-5 or worst_box > 2e-3 or rep["images_missing"]:
        raise RuntimeError("the carousel is not where it was: %s" % rep)
    return rep