"""Grouper: the model's own points that the concept render shows plainly, for fitting the concept's camera (gr_concept_fit.py).
Read-only: blender -b Tender_Grouper.blend --python build/gr_landmarks.py   -> build/checks/landmarks.json"""
import bpy, bmesh, os, json
from mathutils import Vector
HERE = os.path.dirname(os.path.abspath(__file__))
D = bpy.data
for ob in D.objects:
    if ob.animation_data:
        for fc in ob.animation_data.drivers:
            fc.driver.expression = fc.driver.expression
            fc.driver.is_valid = True
        ob.update_tag()
bpy.context.view_layer.update()


def islands(o, pred):
    me = o.data
    bm = bmesh.new(); bm.from_mesh(me); bm.faces.ensure_lookup_table()
    todo = {f.index for f in bm.faces if pred(f)}
    out = []
    while todo:
        s = todo.pop(); isl = [s]; st = [s]
        while st:
            f = bm.faces[st.pop()]
            for e in f.edges:
                for g in e.link_faces:
                    if g.index in todo:
                        todo.discard(g.index); isl.append(g.index); st.append(g.index)
        M = o.matrix_world
        A = sum(bm.faces[i].calc_area() for i in isl)
        c = sum(((M @ bm.faces[i].calc_center_median()) * bm.faces[i].calc_area() for i in isl), Vector()) / A
        out.append((A, c))
    bm.free()
    return out


P = {}
for n in ("SOCKET_Lamp_L", "SOCKET_Lamp_R", "SOCKET_PodLamp_L", "SOCKET_PodLamp_R", "SOCKET_Scanner"):
    P[n] = list(D.objects[n].matrix_world.translation)
gl = sorted(islands(D.objects["SM_Grouper_Glass"], lambda f: True), key=lambda t: -t[0])
for A, c in gl[:6]:
    print("GLASS island", round(A, 3), [round(v, 3) for v in c])
big = [t for t in gl if t[0] > 0.05]
front = min(big, key=lambda t: abs(t[1].x) + 0 * t[1].y)
P["front_glass"] = list(front[1])
P["side_glass_R"] = list(min(big, key=lambda t: t[1].x)[1])
P["side_glass_L"] = list(max(big, key=lambda t: t[1].x)[1])
dr = D.objects["SM_Grouper_Door_R"]
ai = [i for i, m in enumerate(dr.data.materials) if m and m.name == "M_Grouper_Acrylic"][0]
po = islands(dr, lambda f: f.material_index == ai)
P["porthole_R"] = list(max(po, key=lambda t: t[0])[1])
hv = [D.objects["SM_Grouper_Hatch"].matrix_world @ v.co for v in D.objects["SM_Grouper_Hatch"].data.vertices]
P["hatch_top"] = [0.0, -0.09, max(v.z for v in hv)]
hull = D.objects["SM_Grouper_Hull"]
duct_y = max((hull.matrix_world @ v.co).y for v in hull.data.vertices)
P["duct_aft"] = [0.0, duct_y, -0.0759]
rep = json.load(open(os.path.join(HERE, "surfaces_report.json")))
for k in ("lettering_R", "seal_R", "insignia_R"):
    P[k] = rep["decals"][k]["centre"]
P = {k: [round(float(c), 4) for c in v] for k, v in P.items()}
json.dump(P, open(os.path.join(HERE, "checks", "landmarks.json"), "w"), indent=1)
print("LANDMARKS", json.dumps(P))