class_name ContentPaths
extends RefCounted
## Canonical project-managed content directories and legacy path migration.

const STICKMEN_DIR: String = "res://content/stickmen"
const PROPS_DIR: String = "res://content/props"
const STAGES_DIR: String = "res://content/stages"

const LEGACY_DIRS: Dictionary = {
	"stickmen": "content/stickmen",
	"props": "content/props",
	"game_scenes": "content/stages",
}


static func canonicalize(path: String) -> String:
	if path.is_empty():
		return path
	var normalized: String = path.replace("\\", "/")
	if normalized.begins_with("res://"):
		var relative_path: String = normalized.substr("res://".length())
		var migrated: String = _canonicalize_relative(relative_path)
		return "res://" + migrated if migrated != relative_path else path
	if normalized.begins_with("user://"):
		return path
	if normalized.is_absolute_path():
		return _canonicalize_absolute(normalized, path)
	var migrated_relative: String = _canonicalize_relative(normalized)
	return migrated_relative if migrated_relative != normalized else path


static func _canonicalize_relative(path: String) -> String:
	var normalized: String = path.simplify_path()
	for legacy_dir: String in LEGACY_DIRS:
		var canonical_dir: String = String(LEGACY_DIRS[legacy_dir])
		if normalized == legacy_dir:
			return canonical_dir
		var prefix: String = legacy_dir + "/"
		if normalized.begins_with(prefix):
			return canonical_dir + "/" + normalized.substr(prefix.length())
	return path


static func _canonicalize_absolute(path: String, original_path: String) -> String:
	var project_root: String = ProjectSettings.globalize_path("res://").replace("\\", "/").trim_suffix("/")
	if path == project_root:
		return original_path
	var project_prefix: String = project_root + "/"
	if not path.begins_with(project_prefix):
		return original_path
	var relative_path: String = path.substr(project_prefix.length())
	var migrated: String = _canonicalize_relative(relative_path)
	if migrated == relative_path:
		return original_path
	return project_root.path_join(migrated)