"""Study only: the deck's two contours in order (well and outer), and how its quads run."""
import json
import math
import os

import bmesh
import bpy

HERE = os.path.dirname(os.path.abspath(__file__))
ob = bpy.data.objects["Moonpool | deck around open well"]
bm = bmesh.new()
bm.from_mesh(ob.data)
bm.transform(ob.matrix_world)
bm.verts.ensure_lookup_table()
bm.faces.ensure_lookup_table()
ztop = max(v.co.z for v in bm.verts)
top_faces = [f for f in bm.faces if f.normal.z > 0.9]
# edges of the top sheet that belong to one top face only = the two contours
cnt = {}
for f in top_faces:
    for e in f.edges:
        cnt[e.index] = cnt.get(e.index, 0) + 1
bm.edges.ensure_lookup_table()
border = [bm.edges[i] for i, c in cnt.items() if c == 1]
adj = {}
for e in border:
    a, b = e.verts
    adj.setdefault(a.index, []).append(b.index)
    adj.setdefault(b.index, []).append(a.index)
loops = []
seen = set()
for start in adj:
    if start in seen:
        continue
    loop = [start]
    seen.add(start)
    cur, prev = start, None
    while True:
        nxt = [n for n in adj[cur] if n != prev and n not in seen]
        if not nxt:
            break
        prev, cur = cur, nxt[0]
        loop.append(cur)
        seen.add(cur)
    loops.append(loop)
loops.sort(key=lambda l: max(abs(bm.verts[i].co.y) for i in l))
inner, outer = loops[0], loops[-1]
uv = bm.loops.layers.uv["UV0"]
uv1 = bm.loops.layers.uv["UV1_Lightmap"]
rec = {"n_loops": len(loops), "inner_n": len(inner), "outer_n": len(outer), "ztop": ztop,
       "inner": [[round(bm.verts[i].co.x, 4), round(bm.verts[i].co.y, 4)] for i in inner],
       "outer": [[round(bm.verts[i].co.x, 4), round(bm.verts[i].co.y, 4)] for i in outer]}
# pairing: each top quad has two inner and two outer verts
iset, oset = set(inner), set(outer)
pairs = {}
for f in top_faces:
    vi = [v.index for v in f.verts if v.index in iset]
    vo = [v.index for v in f.verts if v.index in oset]
    for e in f.edges:
        a, b = e.verts[0].index, e.verts[1].index
        if (a in iset) != (b in iset):
            pairs[a if a in iset else b] = b if a in iset else a
rec["pairs"] = [[inner.index(i), outer.index(o)] for i, o in pairs.items()]
f = top_faces[0]
rec["uv0_face"] = [[[round(l.vert.co.x, 3), round(l.vert.co.y, 3)], [round(l[uv].uv.x, 4), round(l[uv].uv.y, 4)], [round(l[uv1].uv.x, 4), round(l[uv1].uv.y, 4)]] for l in f.loops]
side = [f for f in bm.faces if abs(f.normal.z) < 0.5][:2]
rec["uv0_side"] = [[[[round(l.vert.co.x, 3), round(l.vert.co.y, 3), round(l.vert.co.z, 3)], [round(l[uv].uv.x, 4), round(l[uv].uv.y, 4)]] for l in f.loops] for f in side]
rec["sharp_edges"] = sum(1 for e in bm.edges if not e.smooth)
rec["custom"] = {k: (list(ob[k]) if hasattr(ob[k], "__len__") and not isinstance(ob[k], str) else ob[k]) for k in ob.keys()}
with open(os.path.join(HERE, "study_deck2.json"), "w", encoding="utf-8") as fh:
    json.dump(rec, fh, default=str)
print("STUDY written")