# Stage 16 (diagnosis only — writes nothing): measure the three defects Jeremy named, so the
# fixes target what is actually there instead of repeating stages 11-15.
#
#   blender --background --python 16_diagnose.py -- <in.blend> <orig.blend> [scratch_dir]
#
# 1. CUT LINES. Are they still topology (disconnected panel runs / holes) after stage 15's weld,
#    or are they now a purely geometric groove? Reports boundary edges, non-manifold edges,
#    degenerate faces, and — for the strongest shading-kink clusters — the groove depth in mm
#    measured perpendicular to the line. Depth tells us whether to weld harder or to fillet.
# 2. DISCOLOURATION. Finds the repainted texels by diffing this blend's packed basecolor against
#    the ORIGINAL texture, then reports mean RGB inside the patch vs a ring of untouched skin
#    just outside it. A tone STEP at the boundary is a Poisson problem; a uniform offset over the
#    whole patch is a levelling problem. The numbers separate them.
# 3. CLEAVAGE. Samples the medial (sternum) corridor for concavity: minimum principal-curvature
#    radius per height, so "sharp crease" vs "round fillet" is a number, not an opinion.
import bpy, bmesh, sys, os, time, math
import numpy as np

argv = sys.argv[sys.argv.index("--") + 1:]
BLEND = argv[0]
ORIG = argv[1] if len(argv) > 1 else ""
SCRATCH = argv[2] if len(argv) > 2 else "."
t0 = time.time()


def log(m):
    print(f"[diag {time.time()-t0:6.1f}s] {m}", flush=True)


def body_of():
    return max([o for o in bpy.data.objects if o.type == 'MESH'],
               key=lambda o: len(o.data.vertices))


# =============================================================================
# 1. TOPOLOGY + CUT LINES
# =============================================================================
bpy.ops.wm.open_mainfile(filepath=BLEND)
ob = body_of()
me = ob.data
n_v = len(me.vertices)
n_f = len(me.polygons)
log(f"mesh '{ob.name}': {n_v} verts, {n_f} faces, custom_normals={me.has_custom_normals}")

co = np.empty(n_v * 3)
me.vertices.foreach_get("co", co)
co = co.reshape(-1, 3)
print(f"BBOX z {co[:,2].min():.3f}..{co[:,2].max():.3f}  "
      f"x {co[:,0].min():.3f}..{co[:,0].max():.3f}  y {co[:,1].min():.3f}..{co[:,1].max():.3f}")

bm = bmesh.new()
bm.from_mesh(me)
bnd = [e for e in bm.edges if len(e.link_faces) == 1]
nonman = [e for e in bm.edges if len(e.link_faces) > 2]
degen = [f for f in bm.faces if f.calc_area() < 1e-12]
loose = [v for v in bm.verts if not v.link_faces]
print(f"TOPO boundary_edges={len(bnd)} nonmanifold_edges={len(nonman)} "
      f"degenerate_faces={len(degen)} loose_verts={len(loose)}")
# where are the holes? cluster boundary verts by height
if bnd:
    bz = np.array([v.co.z for e in bnd for v in e.verts])
    hist, edges = np.histogram(bz, bins=12)
    print("BOUNDARY-EDGE z histogram (holes live here):")
    for c, lo, hi in zip(hist, edges[:-1], edges[1:]):
        if c:
            print(f"   z {lo:.3f}-{hi:.3f}: {c}")
bm.free()

# ---- shading kinks = the visible lines ----
nrm = np.empty(n_v * 3)
me.vertices.foreach_get("normal", nrm)
nrm = nrm.reshape(-1, 3)
ev = np.empty(len(me.edges) * 2, dtype=np.int32)
me.edges.foreach_get("vertices", ev)
ev = ev.reshape(-1, 2)
order = np.concatenate([ev[:, 0], ev[:, 1]])
nbr = np.concatenate([ev[:, 1], ev[:, 0]])
srt = np.argsort(order, kind="stable")
o_s, n_s = order[srt], nbr[srt]
ptr = np.searchsorted(o_s, np.arange(n_v + 1))
cnt = np.maximum(np.diff(ptr), 1)


def nbr_mean(X):
    acc = np.add.reduceat(X[n_s], ptr[:-1], axis=0)
    empty = np.diff(ptr) == 0
    acc[empty] = X[empty]
    return acc / cnt[:, None]


N = nrm.copy()
for _ in range(5):
    N = nbr_mean(N)
    N /= np.maximum(np.linalg.norm(N, axis=1, keepdims=True), 1e-12)
ang = np.degrees(np.arccos(np.clip((nrm * N).sum(axis=1), -1, 1)))

# signed offset from the locally-smooth surface: negative = groove, positive = ridge
sm = co.copy()
for _ in range(12):
    sm = nbr_mean(sm)
dev = ((co - sm) * N).sum(axis=1)          # metres, along the smooth normal

torso = (co[:, 2] > 0.28) & (co[:, 2] < 0.90)
for thr in (8.0, 12.0, 20.0):
    k = torso & (ang > thr)
    print(f"KINK >{thr:4.1f}deg : {k.sum():6d} verts  "
          f"(groove depth p05={np.percentile(dev[k],5)*1000:+.3f} mm, "
          f"median={np.median(dev[k])*1000:+.3f} mm, "
          f"p95={np.percentile(dev[k],95)*1000:+.3f} mm)" if k.sum() else f"KINK >{thr}: none")

kink = torso & (ang > 12.0)
if kink.sum():
    hist, edges = np.histogram(co[kink, 2], bins=16)
    print("KINK z histogram (the lines):")
    for c, lo, hi in zip(hist, edges[:-1], edges[1:]):
        if c > 20:
            print(f"   z {lo:.3f}-{hi:.3f}: {c:5d}")

# are kink verts topologically split? count how many sit on a boundary or have a
# near-duplicate vertex that is NOT an edge-neighbour (= two panels touching, unmerged)
from mathutils import Vector
from mathutils.kdtree import KDTree
kidx = np.nonzero(kink)[0]
sample = kidx[::max(1, len(kidx) // 4000)]
kd = KDTree(n_v)
for i in range(n_v):
    kd.insert(Vector(co[i]), i)
kd.balance()
nbrs = [set() for _ in range(0)]
adj = {}
for a, b in ev:
    adj.setdefault(a, set()).add(b)
    adj.setdefault(b, set()).add(a)
split = 0
for i in sample:
    for (_, j, d) in kd.find_range(Vector(co[i]), 0.0008):
        if j != i and j not in adj.get(i, ()):
            split += 1
            break
print(f"SPLIT-PANEL test on {len(sample)} kink verts: {split} "
      f"({100.0*split/max(len(sample),1):.1f}%) have an unmerged twin within 0.8 mm")

# =============================================================================
# 3. CLEAVAGE — concavity of the medial corridor
# =============================================================================
print("\n=== CLEAVAGE: medial corridor cross-sections y(x) ===")
front = co[:, 1] < 0
for z0 in np.arange(0.62, 0.745, 0.015):
    row = []
    for x0 in np.arange(-0.05, 0.0501, 0.005):
        m = front & (np.abs(co[:, 0] - x0) < 0.0035) & (np.abs(co[:, 2] - z0) < 0.004)
        row.append(co[m, 1].min() if m.sum() else np.nan)
    row = np.array(row)
    if np.isnan(row).all():
        continue
    # curvature of the y(x) profile at the sternum: second difference over 5 mm steps
    mid = len(row) // 2
    seg = row[max(0, mid - 3):mid + 4]
    if len(seg) >= 3 and not np.isnan(seg).any():
        d2 = (seg[:-2] - 2 * seg[1:-1] + seg[2:]) / (0.005 ** 2)
        kmax = np.nanmax(d2)
        rad = 1.0 / kmax if kmax > 1e-6 else float('inf')
        print(f"  z={z0:.3f} sternum y={row[mid]:+.4f}  "
              f"max concave curvature {kmax:8.1f} 1/m  -> fillet radius "
              f"{rad*1000:6.1f} mm" + ("   <-- SHARP" if rad < 0.012 else ""))

print("\n=== CLEAVAGE: depth of the notch (breast apex y vs sternum y) ===")
for z0 in np.arange(0.62, 0.745, 0.015):
    ms = front & (np.abs(co[:, 0]) < 0.004) & (np.abs(co[:, 2] - z0) < 0.004)
    ma = front & (np.abs(np.abs(co[:, 0]) - 0.034) < 0.005) & (np.abs(co[:, 2] - z0) < 0.004)
    if ms.sum() and ma.sum():
        print(f"  z={z0:.3f}  sternum {co[ms,1].min():+.4f}  apex {co[ma,1].min():+.4f}  "
              f"notch {(co[ms,1].min()-co[ma,1].min())*1000:+6.1f} mm")

# =============================================================================
# 2. DISCOLOURATION — repainted texels vs surrounding skin
# =============================================================================
def grab_images():
    out = {}
    for i in bpy.data.images:
        nm = i.name.lower()
        if "basecolor" in nm:
            out["base"] = i
    return out


def px(img):
    w, h = img.size
    b = np.empty(w * h * 4, dtype=np.float32)
    img.pixels.foreach_get(b)
    return b.reshape(h, w, 4)[:, :, :3].astype(np.float32), w, h


cur = grab_images()
if "base" not in cur:
    print("\nDISCOLOUR: no basecolor image found; skipping")
else:
    A, w, h = px(cur["base"])
    log(f"current basecolor {w}x{h} '{cur['base'].name}'")
    np.save(os.path.join(SCRATCH, "cur_base.npy"), A)
    if ORIG and os.path.exists(ORIG):
        bpy.ops.wm.open_mainfile(filepath=ORIG)
        og = grab_images()
        if "base" in og:
            B, w2, h2 = px(og["base"])
            log(f"original basecolor {w2}x{h2} '{og['base'].name}'")
            if (w2, h2) == (w, h):
                d = np.abs(A - B).max(axis=2)
                mask = d > 0.02
                print(f"\nDISCOLOUR: repainted texels = {int(mask.sum())} "
                      f"({100.0*mask.sum()/(w*h):.2f}% of atlas)")

                def dil(m, k):
                    g = m.copy()
                    for _ in range(k):
                        n = g.copy()
                        n[1:, :] |= g[:-1, :]
                        n[:-1, :] |= g[1:, :]
                        n[:, 1:] |= g[:, :-1]
                        n[:, :-1] |= g[:, 1:]
                        g = n
                    return g

                inner = mask & ~dil(~mask, 6)        # 6 px in from the patch edge
                ring = dil(mask, 10) & ~dil(mask, 2)  # untouched skin just outside
                if inner.any() and ring.any():
                    mi = A[inner].mean(axis=0)
                    mr = A[ring].mean(axis=0)
                    print(f"  patch interior mean RGB {mi[0]:.4f} {mi[1]:.4f} {mi[2]:.4f}")
                    print(f"  outside ring  mean RGB {mr[0]:.4f} {mr[1]:.4f} {mr[2]:.4f}")
                    print(f"  OFFSET (patch-ring)     {mi[0]-mr[0]:+.4f} {mi[1]-mr[1]:+.4f} "
                          f"{mi[2]-mr[2]:+.4f}   (luma {(mi.mean()-mr.mean()):+.4f})")
                    print(f"  patch interior stddev   {A[inner].std(axis=0)}")
                    print(f"  ring          stddev    {A[ring].std(axis=0)}")
                    # per-region: split the mask into connected blobs and report the big ones
                    lab = np.zeros(mask.shape, dtype=np.int32)
                    cur_l = 0
                    ys, xs = np.nonzero(mask)
                    seen = np.zeros(mask.shape, dtype=bool)
                    from collections import deque
                    blobs = []
                    for y0, x0 in zip(ys, xs):
                        if seen[y0, x0]:
                            continue
                        cur_l += 1
                        q = deque([(y0, x0)])
                        seen[y0, x0] = True
                        cells = []
                        while q:
                            y, x = q.popleft()
                            cells.append((y, x))
                            for dy, dx in ((1, 0), (-1, 0), (0, 1), (0, -1)):
                                yy, xx = y + dy, x + dx
                                if 0 <= yy < h and 0 <= xx < w and mask[yy, xx] and not seen[yy, xx]:
                                    seen[yy, xx] = True
                                    q.append((yy, xx))
                        if len(cells) > 2000:
                            blobs.append(cells)
                    print(f"  {len(blobs)} patch blobs >2000 texels")
                    for bi, cells in enumerate(sorted(blobs, key=len, reverse=True)[:8]):
                        cy = np.array([c[0] for c in cells])
                        cx = np.array([c[1] for c in cells])
                        bm_ = np.zeros(mask.shape, dtype=bool)
                        bm_[cy, cx] = True
                        bin_ = bm_ & ~dil(~bm_, 5)
                        br_ = dil(bm_, 10) & ~dil(bm_, 2) & ~mask
                        if bin_.any() and br_.any():
                            a_ = A[bin_].mean(axis=0)
                            r_ = A[br_].mean(axis=0)
                            print(f"    blob{bi}: {len(cells):7d} px  uv~({cx.mean()/w:.3f},"
                                  f"{cy.mean()/h:.3f})  offset {a_[0]-r_[0]:+.4f} "
                                  f"{a_[1]-r_[1]:+.4f} {a_[2]-r_[2]:+.4f}  luma "
                                  f"{a_.mean()-r_.mean():+.4f}")
                    np.save(os.path.join(SCRATCH, "patch_mask.npy"), mask)
                    log(f"saved patch_mask.npy ({int(mask.sum())} texels)")
            else:
                print(f"DISCOLOUR: size mismatch {w}x{h} vs {w2}x{h2}")
print("DIAG_DONE")