PartsManager={}
local pm={}

--- ensure part is initialized
local function initPart(part)
	local part_key=part
	if pm[part_key] == nil then
		pm[part_key]={}
	end
	pm[part_key].part=part
	if pm[part_key].functions == nil then
		pm[part_key].functions = {}
	end
	if pm[part_key].init==nil then
		pm[part_key].init="true"
	end
end
--- Add function to part in PartsManager.
--- @param part table Any object with a setEnabled() method.
--- @param func function Function to add to model part's function chain.
--- @param init? boolean Default value for chain. Should only be set once, subsequent uses overwrite the entire chain's initial value.
function PartsManager.addPartFunction(part, func, init)
	initPart(part)
	local part_key=part
	if init ~= nil then
		pm[part_key].init=init
	end
	table.insert(pm[part_key]["functions"], func)
end

--- Set initial value for chain.
--- @param part table Any object with a setEnabled() method.
--- @param init? boolean Default value for chain. Should only be set once, subsequent uses overwrite the entire chain's initial value.
function PartsManager.setInitialValue(part, init)
	assert(init~=nil)
	initPart(part)
	local part_key=part
	pm[part_key].init=init
end

--- Set initial value for chain on all objects in table.
--- @param list table A table containing objects with a setEnabled() method.
--- @param init? boolean Default value for chain. Should only be set once, subsequent uses overwrite the entire chain's initial value.
function PartsManager.setListInitialValue(list, init)
	assert(init~=nil)
	for _, v in pairs(list) do
		PartsManager.setInitialValue(v, init)
	end
end

---@deprecated misleading naming, use setListInitialValue instead
function PartsManager.setGroupInitialValue(list, init)
	return PartsManager.setListInitialValue(list, init)
end

--- Evaluate a part's chain to determine if it should be visible.
--- @param part table An object managed by PartsManager.
function PartsManager.evaluatePart(part)
	local part_key=part
	assert(pm[part_key] ~= nil)

	local evalFunc=function(x, y) return y(x) end
	local init=pm[part_key].init
	return util.ireduce(evalFunc, pm[part_key].functions, true)
end
local evaluatePart=PartsManager.evaluatePart

--- Refresh (enable or disable) a part based on the result of it's chain.
--- @param part table An object managed by PartsManager.
function PartsManager.refreshPart(part)
	local part_enabled=evaluatePart(part)
	part:setVisible(part_enabled)
	return part_enabled
end

--- Refresh a list of parts
--- @param list table A table containing objects with a setEnabled() method.
function PartsManager.refreshPartList(list)
	for _, v in pairs(list) do
		PartsManager.refreshPart(v)
	end
end

--- Refresh all parts managed by PartsManager.
function PartsManager.refreshAll()
	for _, v in pairs(pm) do
		PartsManager.refreshPart(v.part)
	end
end

--- Add function to list of parts in PartsManager
--- @param list table A table containing objects with a setEnabled() method.
--- @param func function Function to add to each model part's function chain.
--- @param default? boolean Default value for chain. Should only be set once, subsequent uses overwrite the entire chain's initial value.
function PartsManager.addPartListFunction(list, func, default)
	for _, v in ipairs(list) do
		PartsManager.addPartFunction(v, func, default)
	end
end

---@deprecated misleading naming, use addPartListFunction instead
function PartsManager.addPartGroupFunction(list, func, default)
	return PartsManager.addPartListFunction(list, func, default)
end

return PartsManager