LoadCharacter.lua

local Players = game:GetService("Players")

local R15Blank = game:GetService("ReplicatedStorage"):WaitForChild("Assets"):WaitForChild("R15Blank")

local LoadCharacter = {}

-- Generally useful types
export type BrickColorID = number
export type AssetType = string
export type CharacterAsset = {
	id: number,
	assetType: {
		name: AssetType,
		id: number,
	},
	name: string,
}
export type CharacterAppearance = {
	playerAvatarType: Enum.GameAvatarType,
	defaultPantsApplied: boolean,
	defaultShirtApplied: boolean,
	scales: {
		bodyType: number,
		head: number,
		height: number,
		proportion: number,
		depth: number,
		width: number,
	},
	bodyColors: {
		leftArmColorId: BrickColorID,
		torsoColorId: BrickColorID,
		rightArmColorId: BrickColorID,
		headColorId: BrickColorID,
		leftLegColorId: BrickColorID,
		rightLeftColorId: BrickColorID,
	},
	assets: Array<CharacterAsset>,
}

-- Internal types
export type HumanoidDescriptionModifier =  (description: HumanoidDescription) -> HumanoidDescription

local function doesPropertyExist(object: Instance, property: string)
	local exists,_ = pcall(function()
		assert(object[property], "oof")
	end)
	return exists
end

--[=[
	Generates a character model from a HumanoidDescription object.
	@param description HumanoidDescription --
	@return Model
]=]
function LoadCharacter.fromHumanoidDescription(description: HumanoidDescription): Model
	local cloneBlank = R15Blank:Clone()
	if (not cloneBlank:IsDescendantOf(workspace)) then
		cloneBlank.Parent = workspace
	end
	cloneBlank:FindFirstChild("Humanoid"):ApplyDescription(description)
	return cloneBlank
end

--[=[
	Generates a character model from a userId. The userId must exist within the game and whatever cavets Players:GetCharacterAppearanceInfoAsync() has.
	Also note this function is more-or-less a binding around LoadCharacter.fromHumanoidDescription(), that may suit your needs
	@param userId number -- This is the userId you wish to use
	@param modifier HumanoidDescriptionModifier -- A function which can modify the humanoid description
	@return Model
]=]
function LoadCharacter.fromUserId(userId: number, modifier: HumanoidDescriptionModifier): Model
	local characterData: CharacterAppearance = Players:GetCharacterAppearanceInfoAsync(userId)
	local description = Instance.new("HumanoidDescription")

	for colorName, value in pairs(characterData.bodyColors) do
		local colorProperty: string, _ = colorName:sub(1,-3):gsub("^%l", string.upper)
		if (doesPropertyExist(description, colorProperty)) then
			description[colorProperty] = BrickColor.new(value).Color
		else
			warn(colorProperty, "did not exist!")
		end
	end

	for scaleName, value in pairs(characterData.scales) do
		local scaleProperty: string, _ = (scaleName .. "Scale"):gsub("^%l", string.upper)
		if (doesPropertyExist(description, scaleProperty)) then
			description[scaleProperty] = value
		else
			warn(scaleProperty, "did not exist!")
		end
	end

	for _, assetData in ipairs(characterData.assets) do
		local assetTypeSpaceless: string, _ = assetData.assetType.name:gsub("%s+", "")

		if (doesPropertyExist(description, assetTypeSpaceless)) then
			if (assetTypeSpaceless:find("Accessory")) then
				description[assetTypeSpaceless] = description[assetTypeSpaceless] .. "," .. assetData.id
				continue
			end
			description[assetTypeSpaceless] = assetData.id
			continue
		end

		if (doesPropertyExist(description, assetTypeSpaceless .. "Accessory")) then
			description[assetTypeSpaceless .. "Accessory"] = description[assetTypeSpaceless .. "Accessory"] .. "," .. assetData.id
			continue
		end

		warn(assetData.assetType.name, "did not exist!")
	end

	if (modifier and type(modifier) == "function") then
		description = modifier(description)
	end

	return LoadCharacter.fromHumanoidDescription(description)
end

--[=[
	Generates a character model from a Player object.
	Also note this function is more-or-less a binding around LoadCharacter.fromHumanoidDescription() and LoadCharacter.fromUserId, which either may suit your needs
	@param userId number -- This is the userId you wish to use
	@param modifier HumanoidDescriptionModifier -- A function which can modify the humanoid description
	@return Model
]=]
function LoadCharacter.fromPlayer(player: Player, modifier: HumanoidDescriptionModifier)
	return LoadCharacter.fromUserId(player.UserId, modifier)
end

return LoadCharacter