@tool
extends EditorScript

# Editor tool: convert each dasher_*.glb into an AnimationLibrary .tres file
# with tracks retargeted to the player rig (GeneralSkeleton + Mixamo bone names).
#
# Run once in the Godot editor:
#   File > Run (Ctrl+Shift+X) on this script, OR
#   from a @tool script: EditorInterface.get_resource_filesystem().scan()
#
# Output:
#   assets/characters/animations/dasher_<name>.tres   (one per glb)
# Plus a combined library:
#   assets/characters/animations/dasher-pack.tres
#
# Run build_dasher_pack.gd after this to consolidate.

const DASHER_DIR := "res://assets/characters/dashers"
const ANIM_DIR := "res://assets/characters/animations"

# Map dasher glb bone names (Blender/standard) -> player rig bone names (Mixamo).
# Tracks whose node name is not in this map are dropped (e.g. helper "head_end" empties).
const BONE_REMAP := {
	"bob-hold": "Hips",          # root of the dasher glb
	"spine": "Hips",
	"spine.001": "Spine",
	"head": "Head",
	"hand.L": "LeftHand",
	"hand.R": "RightHand",
	"forearm.L": "LeftLowerArm",
	"forearm.R": "RightLowerArm",
	"upper_arm.L": "LeftUpperArm",
	"upper_arm.R": "RightUpperArm",
	"shoulder.L": "LeftShoulder",
	"shoulder.R": "RightShoulder",
	"leg.L": "LeftLowerLeg",
	"leg.R": "RightLowerLeg",
	"thigh.L": "LeftUpperLeg",
	"thigh.R": "RightUpperLeg",
	"foot.L": "LeftFoot",
	"foot.R": "RightFoot",
	"toe.L": "LeftToeBase",
	"toe.R": "RightToeBase",
}

const TRACK_TYPES := [
	"position",        # 3D position tracks
	"rotation",        # 3D rotation tracks (quaternion)
	"scale",           # 3D scale tracks
]

func _run() -> void:
	var dasher_dir := DirAccess.open(DASHER_DIR)
	if not dasher_dir:
		push_error("[Convert] Cannot open %s" % DASHER_DIR)
		return

	var converted: Array[String] = []
	for fname in dasher_dir.get_files():
		if not fname.ends_with(".glb"): continue
		if not fname.begins_with("dasher_"): continue
		var stem := fname.get_basename() # e.g. "dasher_hold"
		var out_path := "%s/%s.res" % [ANIM_DIR, stem]
		var ok := _convert_one("%s/%s" % [DASHER_DIR, fname], stem, out_path)
		if ok:
			converted.append(out_path)
		else:
			push_warning("[Convert] Skipped %s" % fname)

	print("[Convert] %d dasher glb(s) converted: %s" % [converted.size(), converted])

func _convert_one(glb_path: String, anim_name: String, out_path: String) -> bool:
	print("[Convert] %s -> %s" % [glb_path, out_path])
	var doc := GLTFDocument.new()
	var state := GLTFState.new()
	var err := doc.append_from_file(glb_path, state)
	if err != OK:
		push_error("[Convert] append_from_file failed: %d" % err)
		return false

	var scene := doc.generate_scene(state)
	if not scene:
		push_error("[Convert] generate_scene returned null")
		return false

	var src_player: AnimationPlayer = scene.find_child("AnimationPlayer", true, false)
	if not src_player:
		push_error("[Convert] No AnimationPlayer in %s" % glb_path)
		scene.queue_free()
		return false

	var out_lib := AnimationLibrary.new()
	for lib_name in src_player.get_animation_library_list():
		var src_lib := src_player.get_animation_library(lib_name)
		for src_anim_name in src_lib.get_animation_list():
			var src_anim: Animation = src_lib.get_animation(src_anim_name)
			var retargeted := _retarget(src_anim)
			if retargeted and retargeted.get_track_count() > 0:
				out_lib.add_animation(anim_name, retargeted)
				print("  + %s (%d tracks)" % [anim_name, retargeted.get_track_count()])
			else:
				push_warning("  - %s produced 0 tracks after retarget" % src_anim_name)

	scene.queue_free()

	if out_lib.get_animation_list().is_empty():
		push_error("[Convert] Output library is empty for %s" % glb_path)
		return false

	var save_err := ResourceSaver.save(out_lib, out_path)
	if save_err != OK:
		push_error("[Convert] ResourceSaver.save failed: %d" % save_err)
		return false
	return true

func _retarget(src: Animation) -> Animation:
	var dst := Animation.new()
	dst.length = src.length
	dst.loop_mode = src.loop_mode
	dst.step = src.step

	# Map: original_track_idx -> new track path or -1 to drop
	for i in src.get_track_count():
		var orig_path: String = src.track_get_path(i)
		var bone := _extract_bone_name(orig_path)
		if not BONE_REMAP.has(bone):
			# drop helper nodes like head_end, hand.L_end, etc.
			continue

		var new_bone: String = BONE_REMAP[bone]
		var new_path := "%%GeneralSkeleton:%s" % new_bone

		# Match the suffix type (:position/:rotation/:scale)
		var type_suffix := ""
		if orig_path.ends_with(":position"): type_suffix = "position"
		elif orig_path.ends_with(":rotation"): type_suffix = "rotation"
		elif orig_path.ends_with(":scale"): type_suffix = "scale"
		else:
			push_warning("  Unrecognized track path: %s" % orig_path)
			continue

		match type_suffix:
			"position":
				if new_bone != "Hips": continue
				dst.add_track(Animation.TYPE_POSITION_3D)
			"rotation":
				dst.add_track(Animation.TYPE_ROTATION_3D)
			"scale":
				if new_bone != "Hips": continue
				dst.add_track(Animation.TYPE_SCALE_3D)

		var new_idx := dst.get_track_count() - 1
		dst.track_set_path(new_idx, NodePath(new_path))
		dst.track_set_interpolation_type(new_idx, src.track_get_interpolation_type(i))
		dst.track_set_imported(new_idx, src.track_is_imported(i))
		dst.track_set_enabled(new_idx, src.track_is_enabled(i))

		# Copy keyframes
		var key_count := src.track_get_key_count(i)
		for k in key_count:
			var t: float = src.track_get_key_time(i, k)
			var v: Variant = src.track_get_key_value(i, k)
			var trans := src.track_get_key_transition(i, k)
			match type_suffix:
				"position":
					dst.track_insert_key(new_idx, t, v)
				"rotation":
					dst.track_insert_key(new_idx, t, v)
				"scale":
					dst.track_insert_key(new_idx, t, v)
			dst.track_set_key_transition(new_idx, k, trans)
	return dst

func _extract_bone_name(path: String) -> String:
	# Tracks look like: "bob-hold/Skeleton3D:hand.L:rotation"
	# We want the bone name "hand.L".
	# Find the last ":" that precedes a type suffix; everything between the previous
	# ":" (or start) and that ":" is the bone name. Easier: split on ":" and take
	# the second-to-last segment.
	var parts := path.split(":")
	if parts.size() < 2:
		return ""
	# parts[-1] is the type ("rotation" etc), parts[-2] is the bone name
	# but bone names can contain "." (e.g. "hand.L"), so just take parts[-2] as-is.
	return parts[-2]