# v6 bake — aspect-true sleeves + inset tops + raised back (on top of v5):
#   limbs: mirrored cylindrical wrap as v5, but sampling is ASPECT-CORRECT —
#          per limb we measure length L and half-circumference C from the mesh
#          and sample only a centered horizontal strip of the texture
#          (u_span = C/L * texH/texW) so on-body texels stay square: no more
#          horizontal/vertical stretch. Limbs sample the FULL texture (no ink
#          bbox crop) so authored negative space survives. Arms start INSET
#          below the shoulder cap so the sleeve never touches the arm/torso
#          meeting line.
#   torso: v3 planar pieces; back raised (top offset 0.04→0.10), bottom lifted
#          (clip 1.04→1.08), widened (half-width 0.21→0.26) and its arm-weight
#          exclusion relaxed so it rides a little onto the rear shoulder.
# Output: baked_body.png. Run headless:
#   tinqs.console.exe --headless --path tattoo-test -s res://bake_v6.gd
extends SceneTree

const GLTF_PATH := "C:/Users/CAN/tinqs-ltd/ariki-game/assets/quaternius/source-models/Regular_Male_FullBody.gltf"
const SKIN_TEX_PATH := "C:/Users/CAN/tinqs-ltd/ariki-game/assets/quaternius/source-models/T_Regular_Male_Dark_BaseColor_png.png"
const MARKS_V3 := "C:/Users/CAN/tinqs-ltd/design/conceptart/generated-images/tattoo-marks/"
const GEN_DIR := "C:/Users/CAN/tinqs-ltd/tattoo-test/gen-v6/"
const OUT_PATH := "C:/Users/CAN/tinqs-ltd/tattoo-test/baked_body.png"

const INK_COLOR := Color(0.10, 0.085, 0.08)
const INK_OPACITY := 0.88
const DILATE := 4

const LIMBS := [
	# arms: T-pose "up" is the anatomical outer face once arms hang down (the
	# spine→shoulder direction is near-parallel to a T-pose arm — unusable)
	{"label": "arm_r", "tex": GEN_DIR + "v6_arm_r_chiefs-mark.png",
		"bones": ["upperarm_r", "lowerarm_r", "hand_r"], "center": "spine_03",
		"hem": false, "inset": 0.10, "out_up": true},
	{"label": "arm_l", "tex": GEN_DIR + "v6_arm_l_iron-spine.png",
		"bones": ["upperarm_l", "lowerarm_l", "hand_l"], "center": "spine_03",
		"hem": false, "inset": 0.10, "out_up": true},
	{"label": "leg_r", "tex": GEN_DIR + "v6_leg_r_voyagers-current.png",
		"bones": ["thigh_r", "calf_r", "foot_r"], "center": "pelvis",
		"hem": true, "inset": 0.0},
	{"label": "leg_l", "tex": GEN_DIR + "v6_leg_l_storm-bearer.png",
		"bones": ["thigh_l", "calf_l", "foot_l"], "center": "pelvis",
		"hem": true, "inset": 0.0},
]
# v3 torso pieces; back framing raised + widened for v6
const BACK_PATH := MARKS_V3 + "mark-06-hearth-warmth_back_v3.png"
const CHEST_PATH := MARKS_V3 + "mark-09-star-eye_chest_v3.png"
const BACK_HALF_WIDTH := 0.26
const BACK_Y_TOP_OFFSET := 0.10
const BACK_Y_CLIP := 1.08
const CHEST_HALF_WIDTH := 0.21
const CHEST_Y_TOP := 1.50
const CHEST_Y_CLIP := 1.15

var skel: Skeleton3D
var verts: PackedVector3Array
var normals: PackedVector3Array
var uvs: PackedVector2Array
var indices: PackedInt32Array
var armw_any: PackedFloat32Array
var skin_img: Image
var painted_mask: PackedByteArray
var tw: int
var th: int

func _init() -> void:
	var t_start := Time.get_ticks_msec()
	var doc := GLTFDocument.new()
	var state := GLTFState.new()
	if doc.append_from_file(GLTF_PATH, state) != OK:
		push_error("GLTF load failed")
		quit(1)
		return
	var scene := doc.generate_scene(state)

	var body: Node = null
	var stack: Array = [scene]
	while not stack.is_empty():
		var n: Node = stack.pop_back()
		if n is Skeleton3D and skel == null:
			skel = n
		if (n is MeshInstance3D or n.get_class() == "ImporterMeshInstance3D") \
				and String(n.name).to_lower().contains("regularmale"):
			body = n
		for c in n.get_children():
			stack.push_back(c)
	if skel == null or body == null:
		push_error("skeleton or body mesh not found")
		quit(1)
		return

	var mesh = body.mesh
	if mesh is ImporterMesh:
		mesh = mesh.get_mesh()
	var arrays: Array = mesh.surface_get_arrays(0)
	verts = arrays[Mesh.ARRAY_VERTEX]
	normals = arrays[Mesh.ARRAY_NORMAL]
	uvs = arrays[Mesh.ARRAY_TEX_UV]
	var vbones: PackedInt32Array = arrays[Mesh.ARRAY_BONES]
	var vweights = arrays[Mesh.ARRAY_WEIGHTS]
	indices = arrays[Mesh.ARRAY_INDEX]
	var nverts := verts.size()
	var influences := int(float(vbones.size()) / float(nverts))

	var skin: Skin = body.skin
	var bind_bone := PackedInt32Array()
	for i in skin.get_bind_count():
		var b := skin.get_bind_bone(i)
		if b < 0:
			b = skel.find_bone(skin.get_bind_name(i))
		bind_bone.append(b)

	skin_img = Image.load_from_file(SKIN_TEX_PATH)
	skin_img.convert(Image.FORMAT_RGBA8)
	tw = skin_img.get_width()
	th = skin_img.get_height()
	painted_mask = PackedByteArray()
	painted_mask.resize(tw * th)

	# per-vertex weights: per-limb (island pick) + any-arm (torso exclusion)
	var limb_w := {}
	for limb in LIMBS:
		limb_w[limb["label"]] = _weight_sum(bind_bone, vbones, vweights, influences, nverts,
			limb["bones"].slice(0, 2))
	armw_any = _weight_sum(bind_bone, vbones, vweights, influences, nverts,
		["upperarm_l", "lowerarm_l", "hand_l", "upperarm_r", "lowerarm_r", "hand_r"])

	var comp := _uv_components(nverts)
	for limb in LIMBS:
		var root := _dominant_component(comp, limb_w[limb["label"]], nverts)
		_bake_limb_island(limb, comp, root)

	var back_y_top := _bone_pos("neck_01").y + BACK_Y_TOP_OFFSET
	_bake_torso("back hearth-warmth", BACK_PATH, -1.0, BACK_HALF_WIDTH,
		back_y_top, BACK_Y_CLIP, "cover", 0.5, 0.75, 0.85)
	_bake_torso("chest star-eye", CHEST_PATH, 1.0, CHEST_HALF_WIDTH,
		CHEST_Y_TOP, CHEST_Y_CLIP, "width", 0.2, 0.4, 0.5)

	_dilate()
	skin_img.save_png(OUT_PATH)
	print("saved: ", OUT_PATH)
	print("bake took %d ms" % (Time.get_ticks_msec() - t_start))
	quit()

func _weight_sum(bind_bone: PackedInt32Array, vbones: PackedInt32Array, vweights,
		influences: int, nverts: int, names: Array) -> PackedFloat32Array:
	var bone_ids := {}
	for bn in names:
		var idx := skel.find_bone(bn)
		if idx < 0:
			push_error("bone not found: " + str(bn))
		bone_ids[idx] = true
	var binds := {}
	for i in bind_bone.size():
		if bone_ids.has(bind_bone[i]):
			binds[i] = true
	var w := PackedFloat32Array()
	w.resize(nverts)
	for v in nverts:
		var acc := 0.0
		for k in influences:
			if binds.has(vbones[v * influences + k]):
				acc += vweights[v * influences + k]
		w[v] = acc
	return w

func _uv_components(nverts: int) -> PackedInt32Array:
	var parent := PackedInt32Array()
	parent.resize(nverts)
	for i in nverts:
		parent[i] = i
	var ntris := indices.size() / 3
	for t in ntris:
		_union(parent, indices[t * 3], indices[t * 3 + 1])
		_union(parent, indices[t * 3 + 1], indices[t * 3 + 2])
	for i in nverts:
		parent[i] = _find(parent, i)
	return parent

func _find(parent: PackedInt32Array, i: int) -> int:
	while parent[i] != i:
		parent[i] = parent[parent[i]]
		i = parent[i]
	return i

func _union(parent: PackedInt32Array, a: int, b: int) -> void:
	var ra := _find(parent, a)
	var rb := _find(parent, b)
	if ra != rb:
		parent[ra] = rb

func _dominant_component(comp: PackedInt32Array, w: PackedFloat32Array, nverts: int) -> int:
	var sums := {}
	for v in nverts:
		sums[comp[v]] = sums.get(comp[v], 0.0) + w[v]
	var best := -1
	var best_w := 0.0
	for c in sums:
		if sums[c] > best_w:
			best_w = sums[c]
			best = c
	return best

func _bone_pos(bone: String) -> Vector3:
	return skel.get_bone_global_rest(skel.find_bone(bone)).origin

func _ink_bbox(img: Image) -> Rect2:
	var w := img.get_width()
	var h := img.get_height()
	var minx := w
	var maxx := -1
	var miny := h
	var maxy := -1
	for y in h:
		for x in w:
			var c := img.get_pixel(x, y)
			if (c.r + c.g + c.b) / 3.0 < 0.75:
				minx = mini(minx, x)
				maxx = maxi(maxx, x)
				miny = mini(miny, y)
				maxy = maxi(maxy, y)
	return Rect2(float(minx) / w, float(miny) / h,
		float(maxx - minx + 1) / w, float(maxy - miny + 1) / h)

func _sample_crop(img: Image, rect: Rect2, u: float, v: float) -> Color:
	return _sample_bilinear(img,
		rect.position.x + clampf(u, 0.0, 1.0) * rect.size.x,
		rect.position.y + clampf(v, 0.0, 1.0) * rect.size.y)

func _is_skin(px: int, py: int) -> bool:
	var c := skin_img.get_pixel(px, py)
	return (c.r + c.g + c.b) / 3.0 >= 0.30

# cylindrical coords of a 3D point against the limb's bone chain; z = radius
func _limb_coords(pos: Vector3, segs: Array, total_len: float, outward: Vector3) -> Vector3:
	var best_dist := 1e9
	var t_along := 0.0
	var ang := 0.0
	for seg in segs:
		var a: Vector3 = seg[0]
		var axis: Vector3 = (seg[1] as Vector3) - a
		var seg_len := axis.length()
		axis /= seg_len
		var s := clampf((pos - a).dot(axis), 0.0, seg_len)
		var cp: Vector3 = a + axis * s
		var d := pos.distance_to(cp)
		if d < best_dist:
			best_dist = d
			t_along = ((seg[2] as float) + s) / total_len
			var uref: Vector3 = (outward - axis * outward.dot(axis)).normalized()
			var dv: Vector3 = pos - cp
			ang = atan2(dv.dot(axis.cross(uref)), dv.dot(uref))
	return Vector3(ang, t_along, best_dist)

# rows of the design that contain ink, merged into clusters [y0, y1]
func _detect_clusters(tat: Image) -> Array:
	var w := tat.get_width()
	var h := tat.get_height()
	var runs := []
	var s := -1
	for y in h:
		var cnt := 0
		for x in w:
			var c := tat.get_pixel(x, y)
			if (c.r + c.g + c.b) / 3.0 < 0.70:
				cnt += 1
				if cnt >= 3:
					break
		var inky := cnt >= 3
		if inky and s == -1:
			s = y
		elif not inky and s != -1:
			runs.append([s, y - 1])
			s = -1
	if s != -1:
		runs.append([s, h - 1])
	var clusters := []
	for r in runs:
		if clusters.size() > 0 and r[0] - clusters[-1][1] <= 10:
			clusters[-1][1] = r[1]
		else:
			clusters.append(r)
	return clusters

# virtual-canvas row remap: keep ink clusters at true pixel scale, stretch only
# the parchment gaps between them to fill the limb's length. remap[y'] = source
# row, or -1 for parchment. Top/bottom margins keep their authored pixel size.
func _build_remap(clusters: Array, h: int, hprime: int) -> PackedInt32Array:
	var remap := PackedInt32Array()
	remap.resize(hprime)
	remap.fill(-1)
	if clusters.is_empty():
		return remap
	var ink_h := 0
	for c in clusters:
		ink_h += c[1] - c[0] + 1
	var top: int = mini(clusters[0][0], int(0.02 * hprime))
	var bot: int = mini(h - 1 - clusters[-1][1], int(0.03 * hprime))
	var free := hprime - ink_h - top - bot
	if free < 0:  # limb shorter than the design: uniform scale fallback
		for y in hprime:
			remap[y] = int(float(y) * h / hprime)
		return remap
	var gsum := 0.0
	for i in clusters.size() - 1:
		gsum += clusters[i + 1][0] - clusters[i][1] - 1
	var cursor := top
	for i in clusters.size():
		var c: Array = clusters[i]
		for k in c[1] - c[0] + 1:
			if cursor + k < hprime:
				remap[cursor + k] = c[0] + k
		cursor += c[1] - c[0] + 1
		if i < clusters.size() - 1:
			var g := float(clusters[i + 1][0] - c[1] - 1)
			cursor += int(free * (g / gsum if gsum > 0.0 else 1.0 / (clusters.size() - 1)))
	return remap

# ── limb sleeve: mirrored wrap, aspect-true cluster layout, inset top ────────
func _bake_limb_island(limb: Dictionary, comp: PackedInt32Array, root: int) -> void:
	var tat := Image.load_from_file(limb["tex"])
	tat.convert(Image.FORMAT_RGBA8)
	var bones: Array = limb["bones"]
	var p0 := _bone_pos(bones[0])
	var p1 := _bone_pos(bones[1])
	var p2 := _bone_pos(bones[2])
	var center := _bone_pos(limb["center"])
	var len1 := p0.distance_to(p1)
	var total_len := len1 + p1.distance_to(p2)
	var outward := Vector3.UP if limb.get("out_up", false) else (p0 - center).normalized()
	var segs := [[p0, p1, 0.0], [p1, p2, len1]]
	var skip_shorts: bool = limb["hem"]

	# island SKIN vertices: v range (legs hem→ankle, arms cap→wrist) + mean radius
	var t_min := 1e9
	var t_max := -1e9
	var r_sum := 0.0
	var r_n := 0
	for v in verts.size():
		if comp[v] != root:
			continue
		if skip_shorts:
			var sx := clampi(int(uvs[v].x * tw), 0, tw - 1)
			var sy := clampi(int(uvs[v].y * th), 0, th - 1)
			if not _is_skin(sx, sy):
				continue
		var cc := _limb_coords(verts[v], segs, total_len, outward)
		t_min = minf(t_min, cc.y)
		t_max = maxf(t_max, cc.y)
		r_sum += cc.z
		r_n += 1

	# Plain 360° wrap, design column centered on the OUTER face; the seam falls
	# in the design's parchment margins on the inner limb, so it is invisible.
	# Aspect-true: one scale s (px/m) for both axes — the motif column may take
	# up to FRAC_CIRC of the circumference and the ink rows up to FRAC_LEN of
	# the length; parchment gaps between clusters absorb the rest (row remap).
	const FRAC_CIRC := 0.75
	const FRAC_LEN := 0.85
	var r_mean := r_sum / maxf(1.0, float(r_n))
	var t_top := t_min + float(limb["inset"]) * (t_max - t_min)
	var phys_len := (t_max - t_top) * total_len
	var circ := TAU * r_mean
	var crop := _ink_bbox(tat)
	var texw := float(tat.get_width())
	var texh := tat.get_height()
	var crop_w_px := crop.size.x * texw
	var crop_cx := (crop.position.x + crop.size.x * 0.5) * texw
	var clusters := _detect_clusters(tat)
	var ink_rows := 0
	for cl in clusters:
		ink_rows += cl[1] - cl[0] + 1
	var s := maxf(crop_w_px / (FRAC_CIRC * circ), float(ink_rows) / (FRAC_LEN * phys_len))
	var hprime := maxi(1, int(s * phys_len))
	var remap := _build_remap(clusters, texh, hprime)
	print("%s v-range %.3f..%.3f (inset→%.3f) r=%.3f L=%.3f circ=%.3f | %d clusters, ink %dpx, s=%.0f px/m, col=%.2f of circ"
		% [limb["label"], t_min, t_max, t_top, r_mean, phys_len, circ,
		clusters.size(), ink_rows, s, crop_w_px / (s * circ)])

	var painted := 0
	var ntris := indices.size() / 3
	for t in ntris:
		var i0 := indices[t * 3]
		if comp[i0] != root:
			continue
		var i1 := indices[t * 3 + 1]
		var i2 := indices[t * 3 + 2]
		painted += _raster_tri(i0, i1, i2, skip_shorts,
			func(pos: Vector3, _nrm: Vector3, _bary: Vector3) -> float:
				var cc := _limb_coords(pos, segs, total_len, outward)
				var v_norm := (cc.y - t_top) / (t_max - t_top)
				if v_norm < 0.0 or v_norm > 1.0:
					return -1.0
				var src_row := remap[clampi(int(v_norm * (hprime - 1)), 0, hprime - 1)]
				if src_row < 0:
					return 0.0  # parchment gap: bare skin, but mark coverage
				var u_frac := fposmod(0.5 + cc.x / TAU, 1.0)  # 0.5 = outer face
				var x_px := crop_cx + (u_frac - 0.5) * s * circ
				if x_px < 0.0 or x_px >= texw:
					return 0.0  # beyond the canvas: bare skin (seam side)
				var c := _sample_bilinear(tat, x_px / texw, (float(src_row) + 0.5) / texh)
				var ink := 1.0 - smoothstep(0.45, 0.80, (c.r + c.g + c.b) / 3.0)
				return ink * INK_OPACITY * smoothstep(0.0, 0.012, v_norm))
	print(limb["label"], " painted px: ", painted)

# ── torso piece, v3 planar projection with tunable arm-weight exclusion ──────
func _bake_torso(label: String, tex_path: String, facing: float, hw: float,
		y_top: float, y_clip: float, fit: String,
		arm_fade_lo: float, arm_fade_hi: float, arm_skip: float) -> void:
	var tat := Image.load_from_file(tex_path)
	tat.convert(Image.FORMAT_RGBA8)
	var crop := _ink_bbox(tat)
	var aspect := crop.size.y / crop.size.x  # normalized rect → recompute px aspect
	var timg_aspect := float(tat.get_height()) / float(tat.get_width())
	aspect = aspect * timg_aspect / 1.0
	var box_w := 2.0 * hw
	var design_w := box_w
	if fit == "cover":
		design_w = maxf(box_w, (y_top - y_clip) / aspect)
	var design_h := design_w * aspect
	var y_bot := maxf(y_clip, y_top - design_h)
	print("%s: design %.2fw x %.2fh, y %.2f..%.2f" % [label, design_w, design_h, y_bot, y_top])
	var painted := 0
	var ntris := indices.size() / 3
	for t in ntris:
		var i0 := indices[t * 3]
		var i1 := indices[t * 3 + 1]
		var i2 := indices[t * 3 + 2]
		if min(armw_any[i0], min(armw_any[i1], armw_any[i2])) > arm_skip:
			continue
		var ymax := maxf(verts[i0].y, maxf(verts[i1].y, verts[i2].y))
		var ymin := minf(verts[i0].y, minf(verts[i1].y, verts[i2].y))
		if ymin > y_top + 0.05 or ymax < y_bot - 0.05:
			continue
		painted += _raster_tri(i0, i1, i2, true,
			func(pos: Vector3, nrm: Vector3, bary: Vector3) -> float:
				if pos.y < y_bot or pos.y > y_top or absf(pos.x) > hw:
					return -1.0
				var faceness := nrm.z * facing
				if faceness < 0.25:
					return -1.0
				var aw: float = bary.x * armw_any[i0] + bary.y * armw_any[i1] + bary.z * armw_any[i2]
				if aw > arm_fade_hi:
					return -1.0
				var x_norm := (pos.x * facing + hw) / box_w
				var u := 0.5 + (x_norm - 0.5) * (box_w / design_w)
				var v := (y_top - pos.y) / design_h
				if u < 0.0 or u > 1.0 or v > 1.0:
					return -1.0
				var c := _sample_crop(tat, crop, u, v)
				var ink := 1.0 - smoothstep(0.45, 0.80, (c.r + c.g + c.b) / 3.0)
				var alpha := ink * INK_OPACITY * smoothstep(0.25, 0.45, faceness)
				alpha *= 1.0 - smoothstep(arm_fade_lo, arm_fade_hi, aw)
				return alpha)
	print(label, " painted px: ", painted)

# rasterize one triangle in UV space; shade(pos, nrm, bary) → alpha (<=0 skips
# ink but still marks coverage). skip_shorts guards dark shorts texels.
func _raster_tri(i0: int, i1: int, i2: int, skip_shorts: bool, shade: Callable) -> int:
	var p0 := Vector2(uvs[i0].x * tw, uvs[i0].y * th)
	var p1 := Vector2(uvs[i1].x * tw, uvs[i1].y * th)
	var p2 := Vector2(uvs[i2].x * tw, uvs[i2].y * th)
	var denom := (p1.y - p2.y) * (p0.x - p2.x) + (p2.x - p1.x) * (p0.y - p2.y)
	if absf(denom) < 1e-9:
		return 0
	var minx := clampi(int(floor(min(p0.x, min(p1.x, p2.x)))), 0, tw - 1)
	var maxx := clampi(int(ceil(max(p0.x, max(p1.x, p2.x)))), 0, tw - 1)
	var miny := clampi(int(floor(min(p0.y, min(p1.y, p2.y)))), 0, th - 1)
	var maxy := clampi(int(ceil(max(p0.y, max(p1.y, p2.y)))), 0, th - 1)
	var painted := 0
	for py in range(miny, maxy + 1):
		for px in range(minx, maxx + 1):
			var fx := px + 0.5
			var fy := py + 0.5
			var b0 := ((p1.y - p2.y) * (fx - p2.x) + (p2.x - p1.x) * (fy - p2.y)) / denom
			var b1 := ((p2.y - p0.y) * (fx - p2.x) + (p0.x - p2.x) * (fy - p2.y)) / denom
			var b2 := 1.0 - b0 - b1
			if b0 < -0.001 or b1 < -0.001 or b2 < -0.001:
				continue
			if skip_shorts and not _is_skin(px, py):
				continue
			var pos: Vector3 = verts[i0] * b0 + verts[i1] * b1 + verts[i2] * b2
			var nrm: Vector3 = (normals[i0] * b0 + normals[i1] * b1 + normals[i2] * b2).normalized()
			var alpha: float = shade.call(pos, nrm, Vector3(b0, b1, b2))
			painted_mask[py * tw + px] = 1
			if alpha <= 0.003:
				continue
			skin_img.set_pixel(px, py, skin_img.get_pixel(px, py).lerp(INK_COLOR, alpha))
			painted += 1
	return painted

# pull composited colors DILATE px into unpainted texels (seam gutters)
func _dilate() -> void:
	for pass_i in DILATE:
		var grown := PackedInt32Array()
		for y in th:
			for x in tw:
				if painted_mask[y * tw + x] == 1:
					continue
				var acc := Color(0, 0, 0)
				var n := 0
				for d in [[1, 0], [-1, 0], [0, 1], [0, -1]]:
					var nx: int = x + d[0]
					var ny: int = y + d[1]
					if nx < 0 or nx >= tw or ny < 0 or ny >= th:
						continue
					if painted_mask[ny * tw + nx] == 1:
						acc += skin_img.get_pixel(nx, ny)
						n += 1
				if n > 0:
					skin_img.set_pixel(x, y, acc / n)
					grown.append(y * tw + x)
		for p in grown:
			painted_mask[p] = 1

func _sample_bilinear(img: Image, x: float, y: float) -> Color:
	var w := img.get_width()
	var h := img.get_height()
	var fx := clampf(x * w - 0.5, 0.0, w - 1.001)
	var fy := clampf(y * h - 0.5, 0.0, h - 1.001)
	var x0 := int(fx)
	var y0 := int(fy)
	var x1 := mini(x0 + 1, w - 1)
	var y1 := mini(y0 + 1, h - 1)
	var tx := fx - x0
	var ty := fy - y0
	return img.get_pixel(x0, y0).lerp(img.get_pixel(x1, y0), tx) \
		.lerp(img.get_pixel(x0, y1).lerp(img.get_pixel(x1, y1), tx), ty)