extends SceneTree
## Generates the placeholder avatar asset pack (GLB files) referenced by
## assets/avatars/catalog.json.
##
## These are deliberately crude primitive stand-ins so the avatar loader /
## customization / in-world rendering can be built and tested now; real art
## swaps in later as a pure content change (catalog paths are unchanged).
##
## Run:  godot --headless --path . --script res://scripts/tools/gen_placeholder_avatars.gd
## Output: res://assets/avatars/*.glb  (13 attachments + 1 rigged base body)

const OUT_DIR := "res://assets/avatars/"

# Canonical rig — must match avatar_loader.gd CANONICAL_BONES. Each entry:
#   name -> [parent_name, global_rest_position]  (T-pose, Y-up, metres)
const BONES := {
	"Root":          ["",              Vector3(0.00, 0.00, 0.00)],
	"Hips":          ["Root",          Vector3(0.00, 0.95, 0.00)],
	"Spine":         ["Hips",          Vector3(0.00, 1.10, 0.00)],
	"Chest":         ["Spine",         Vector3(0.00, 1.30, 0.00)],
	"Neck":          ["Chest",         Vector3(0.00, 1.48, 0.00)],
	"Head":          ["Neck",          Vector3(0.00, 1.60, 0.00)],
	"HeadTop":       ["Head",          Vector3(0.00, 1.78, 0.00)],
	"Jaw":           ["Head",          Vector3(0.00, 1.56, 0.06)],
	"LeftEye":       ["Head",          Vector3(0.04, 1.64, 0.09)],
	"RightEye":      ["Head",          Vector3(-0.04, 1.64, 0.09)],
	"LeftShoulder":  ["Chest",         Vector3(0.06, 1.42, 0.00)],
	"LeftUpperArm":  ["LeftShoulder",  Vector3(0.18, 1.42, 0.00)],
	"LeftLowerArm":  ["LeftUpperArm",  Vector3(0.44, 1.42, 0.00)],
	"LeftHand":      ["LeftLowerArm",  Vector3(0.68, 1.42, 0.00)],
	"RightShoulder": ["Chest",         Vector3(-0.06, 1.42, 0.00)],
	"RightUpperArm": ["RightShoulder", Vector3(-0.18, 1.42, 0.00)],
	"RightLowerArm": ["RightUpperArm", Vector3(-0.44, 1.42, 0.00)],
	"RightHand":     ["RightLowerArm", Vector3(-0.68, 1.42, 0.00)],
	"LeftUpperLeg":  ["Hips",          Vector3(0.11, 0.90, 0.00)],
	"LeftLowerLeg":  ["LeftUpperLeg",  Vector3(0.11, 0.50, 0.00)],
	"LeftFoot":      ["LeftLowerLeg",  Vector3(0.11, 0.08, 0.04)],
	"RightUpperLeg": ["Hips",          Vector3(-0.11, 0.90, 0.00)],
	"RightLowerLeg": ["RightUpperLeg", Vector3(-0.11, 0.50, 0.00)],
	"RightFoot":     ["RightLowerLeg", Vector3(-0.11, 0.08, 0.04)],
}

# Order matters: parents before children.
const BONE_ORDER := [
	"Root", "Hips", "Spine", "Chest", "Neck", "Head", "HeadTop", "Jaw",
	"LeftEye", "RightEye",
	"LeftShoulder", "LeftUpperArm", "LeftLowerArm", "LeftHand",
	"RightShoulder", "RightUpperArm", "RightLowerArm", "RightHand",
	"LeftUpperLeg", "LeftLowerLeg", "LeftFoot",
	"RightUpperLeg", "RightLowerLeg", "RightFoot",
]

# Body segments: [boneA, boneB, radius]  -> a capsule-ish box between the two,
# fully weighted to boneA. boneB "" means a small blob at boneA.
const SEGMENTS := [
	["Hips", "Spine", 0.14],
	["Spine", "Chest", 0.15],
	["Chest", "Neck", 0.13],
	["Neck", "Head", 0.05],
	["Head", "", 0.11],
	["LeftUpperArm", "LeftLowerArm", 0.055],
	["LeftLowerArm", "LeftHand", 0.045],
	["LeftHand", "", 0.05],
	["RightUpperArm", "RightLowerArm", 0.055],
	["RightLowerArm", "RightHand", 0.045],
	["RightHand", "", 0.05],
	["LeftUpperLeg", "LeftLowerLeg", 0.08],
	["LeftLowerLeg", "LeftFoot", 0.06],
	["LeftFoot", "", 0.06],
	["RightUpperLeg", "RightLowerLeg", 0.08],
	["RightLowerLeg", "RightFoot", 0.06],
	["RightFoot", "", 0.06],
]

# Attachments: id -> [Mesh, local_offset_from_mount_bone, colour]
# Mesh is built in _attachment_mesh().
const ATTACHMENTS := {
	"head_cyber_01":       ["head",     Vector3(0, 0.02, 0.0),  Color(0.20, 0.85, 0.95)],
	"hair_mohawk_01":      ["mohawk",   Vector3(0, 0.02, 0.0),  Color(0.90, 0.20, 0.35)],
	"hair_ponytail_01":    ["ponytail", Vector3(0, 0.0, -0.08), Color(0.45, 0.30, 0.15)],
	"face_glasses_01":     ["glasses",  Vector3(0, 0.06, 0.10), Color(0.10, 0.10, 0.12)],
	"chest_bandit_01":     ["torso",    Vector3(0, 0.0, 0.0),   Color(0.55, 0.20, 0.20)],
	"back_backpack_01":    ["box",      Vector3(0, 0.0, -0.16), Color(0.30, 0.35, 0.25)],
	"pants_cargo_01":      ["hips",     Vector3(0, -0.18, 0.0), Color(0.30, 0.35, 0.45)],
	"left_hand_glove_01":  ["blob",     Vector3(0, 0.0, 0.0),   Color(0.15, 0.15, 0.18)],
	"right_hand_glove_01": ["blob",     Vector3(0, 0.0, 0.0),   Color(0.15, 0.15, 0.18)],
	"left_foot_boot_01":   ["boot",     Vector3(0, -0.02, 0.03), Color(0.12, 0.10, 0.09)],
	"right_foot_boot_01":  ["boot",     Vector3(0, -0.02, 0.03), Color(0.12, 0.10, 0.09)],
	"accessory_belt_01":   ["belt",     Vector3(0, 0.98, 0.0),  Color(0.20, 0.18, 0.12)],
	"accessory_necklace_01": ["belt",   Vector3(0, 1.34, 0.02), Color(0.85, 0.75, 0.20)],
}

var _fail := 0


func _initialize() -> void:
	var abs_dir := ProjectSettings.globalize_path(OUT_DIR)
	DirAccess.make_dir_recursive_absolute(abs_dir)

	_gen_base_body()
	for id in ATTACHMENTS:
		var spec: Array = ATTACHMENTS[id]
		_gen_attachment(id, spec[0], spec[1], spec[2])

	print("\n%s" % ("DONE — all placeholder avatar GLBs written" if _fail == 0
		else "FAILED (%d errors)" % _fail))
	quit(_fail)


# ---------------------------------------------------------------------------
# Base body — rigged, skinned
# ---------------------------------------------------------------------------

func _global_rest(bone: String) -> Transform3D:
	return Transform3D(Basis.IDENTITY, BONES[bone][1])


func _gen_base_body() -> void:
	var root := Node3D.new()
	root.name = "AvatarRoot"

	var skel := Skeleton3D.new()
	skel.name = "Skeleton3D"
	root.add_child(skel)

	var idx := {}
	for bone in BONE_ORDER:
		var i := skel.add_bone(bone)
		idx[bone] = i
	for bone in BONE_ORDER:
		var parent: String = BONES[bone][0]
		var g := _global_rest(bone)
		if parent == "":
			skel.set_bone_rest(idx[bone], g)
		else:
			skel.set_bone_parent(idx[bone], idx[parent])
			skel.set_bone_rest(idx[bone], _global_rest(parent).affine_inverse() * g)
	for bone in BONE_ORDER:
		skel.set_bone_pose_position(idx[bone], skel.get_bone_rest(idx[bone]).origin)

	# Skin: one bind per bone, bind pose = inverse global rest.
	var skin := Skin.new()
	for bone in BONE_ORDER:
		skin.add_named_bind(bone, _global_rest(bone).affine_inverse())

	# Build one ArrayMesh surface from all segments, CPU-skinned to bind indices.
	var verts := PackedVector3Array()
	var normals := PackedVector3Array()
	var bones := PackedInt32Array()
	var weights := PackedFloat32Array()

	var bind_index := {}
	for b in range(BONE_ORDER.size()):
		bind_index[BONE_ORDER[b]] = b

	for seg in SEGMENTS:
		var a: String = seg[0]
		var b: String = seg[1]
		var r: float = seg[2]
		var pa: Vector3 = BONES[a][1]
		var pb: Vector3 = pa + Vector3(0, 0.12, 0) if b == "" else BONES[b][1]
		_append_box_between(verts, normals, bones, weights, pa, pb, r, bind_index[a])

	var arr := []
	arr.resize(Mesh.ARRAY_MAX)
	arr[Mesh.ARRAY_VERTEX] = verts
	arr[Mesh.ARRAY_NORMAL] = normals
	arr[Mesh.ARRAY_BONES] = bones
	arr[Mesh.ARRAY_WEIGHTS] = weights

	var mesh := ArrayMesh.new()
	mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arr)
	var mat := StandardMaterial3D.new()
	mat.albedo_color = Color(0.78, 0.66, 0.55)
	mesh.surface_set_material(0, mat)

	var mi := MeshInstance3D.new()
	mi.name = "Body"
	mi.mesh = mesh
	mi.skin = skin
	skel.add_child(mi)
	mi.skeleton = mi.get_path_to(skel)

	_write_glb(root, "base_human_male_01")
	root.free()


# Append an axis-aligned-ish box spanning pa..pb, all verts weighted 1.0 to bone_idx.
func _append_box_between(verts: PackedVector3Array, normals: PackedVector3Array,
		bones: PackedInt32Array, weights: PackedFloat32Array,
		pa: Vector3, pb: Vector3, r: float, bone_idx: int) -> void:
	var axis := pb - pa
	var len := axis.length()
	if len < 0.001:
		axis = Vector3(0, 0.1, 0)
		len = 0.1
	var dir := axis / len
	var up := Vector3.UP if absf(dir.dot(Vector3.UP)) < 0.95 else Vector3.FORWARD
	var right := dir.cross(up).normalized()
	up = right.cross(dir).normalized()

	var corners: Array[Vector3] = [
		-right * r - up * r, right * r - up * r,
		right * r + up * r, -right * r + up * r,
	]
	# 8 corners: bottom ring at pa, top ring at pb
	var pts: Array[Vector3] = []
	for c in corners:
		pts.append(pa + c)
	for c in corners:
		pts.append(pb + c)

	var faces := [
		[0, 1, 2, 3], [7, 6, 5, 4],       # caps
		[0, 4, 5, 1], [1, 5, 6, 2],       # sides
		[2, 6, 7, 3], [3, 7, 4, 0],
	]
	for f in faces:
		var q: Array[Vector3] = [pts[f[0]], pts[f[1]], pts[f[2]], pts[f[3]]]
		var n: Vector3 = (q[1] - q[0]).cross(q[2] - q[0]).normalized()
		for tri in [[0, 1, 2], [0, 2, 3]]:
			for vi in tri:
				verts.append(q[vi])
				normals.append(n)
				bones.append_array([bone_idx, 0, 0, 0])
				weights.append_array([1.0, 0.0, 0.0, 0.0])


# ---------------------------------------------------------------------------
# Attachments — plain static meshes
# ---------------------------------------------------------------------------

func _gen_attachment(id: String, kind: String, offset: Vector3, col: Color) -> void:
	var root := Node3D.new()
	root.name = "AttachmentRoot"
	var mi := MeshInstance3D.new()
	mi.name = id
	mi.mesh = _attachment_mesh(kind)
	mi.position = offset
	var mat := StandardMaterial3D.new()
	mat.albedo_color = col
	mi.material_override = mat
	root.add_child(mi)
	_write_glb(root, id)
	root.free()


func _attachment_mesh(kind: String) -> Mesh:
	match kind:
		"head":
			var m := SphereMesh.new(); m.radius = 0.13; m.height = 0.26; return m
		"mohawk":
			var m := PrismMesh.new(); m.size = Vector3(0.06, 0.16, 0.30); return m
		"ponytail":
			var m := CapsuleMesh.new(); m.radius = 0.04; m.height = 0.28; return m
		"glasses":
			var m := BoxMesh.new(); m.size = Vector3(0.20, 0.05, 0.02); return m
		"torso":
			var m := BoxMesh.new(); m.size = Vector3(0.34, 0.44, 0.22); return m
		"box":
			var m := BoxMesh.new(); m.size = Vector3(0.26, 0.32, 0.14); return m
		"hips":
			var m := BoxMesh.new(); m.size = Vector3(0.32, 0.30, 0.20); return m
		"blob":
			var m := SphereMesh.new(); m.radius = 0.06; m.height = 0.12; return m
		"boot":
			var m := BoxMesh.new(); m.size = Vector3(0.10, 0.10, 0.20); return m
		"belt":
			var m := TorusMesh.new(); m.inner_radius = 0.12; m.outer_radius = 0.17; return m
		_:
			return BoxMesh.new()


# ---------------------------------------------------------------------------
# GLB export
# ---------------------------------------------------------------------------

func _write_glb(scene_root: Node, basename: String) -> void:
	# append_from_scene needs the node in a tree.
	get_root().add_child(scene_root)
	var doc := GLTFDocument.new()
	var state := GLTFState.new()
	var err := doc.append_from_scene(scene_root, state)
	if err != OK:
		push_error("append_from_scene failed for %s: %s" % [basename, error_string(err)])
		_fail += 1
		get_root().remove_child(scene_root)
		return
	var out_path := ProjectSettings.globalize_path("%s%s.glb" % [OUT_DIR, basename])
	err = doc.write_to_filesystem(state, out_path)
	get_root().remove_child(scene_root)
	if err != OK:
		push_error("write_to_filesystem failed for %s: %s" % [basename, error_string(err)])
		_fail += 1
		return
	print("  wrote %s.glb (%d bytes)" % [basename, FileAccess.get_file_as_bytes(out_path).size()])