--[[
	Snake script by popinman322
--]]

local Players = game:GetService("Players")
local LocalPlayer = Players.LocalPlayer

local PlayerBackpack = LocalPlayer.Backpack

local ToolName = "[ Snake ]"
local HopperProps = {
	Name = ToolName;
	Parent = PlayerBackpack;
}

local function new(Class, Parent, Props)
	local Inst = Instance.new(Class, Parent)
	if Props["FormFactor"] then
		Inst["FormFactor"] = Props["FormFactor"]
	end
	for Prop, Val in pairs(Props) do
		Inst[Prop] = Val
	end
	return Inst
end

-- Snake creation and manipulation

local NumLinks = 20

local Step = CFrame.new(0,0,0.1)
local Steps = {}
local MaxSteps = NumLinks + 1

local function RecordStep(Step)
	local Out = {}
	for i=1, #Steps do
		Out[i+1] = Steps[i]
	end
	Out[#Steps] = nil
	Out[1] = Step
	Steps = Out
end

local function GetStep(Index)
	if Steps[Index] == nil then
		return Steps[#Steps]
	end
	return Steps[Index]
end

local Snake = new("Model", LocalPlayer.Character,
	{
		Name = "Snake"
});

local Head = new("Seat", Snake,
	{
		Name = "Head";
		FormFactor = "Custom";
		BrickColor = BrickColor.Red;
		Reflectance = 0.7;
		Transparency = 0.25;
		Shape = Enum.PartType.Ball;
		Size = Vector3.new(5,5,5);
		Anchored = true;
		TopSurface = "Smooth";
		BottomSurface = "Smooth";
});

local Links = {}

local function NewLink()
	return new("Part", Snake, {
			Name = "Link";
			BrickColor = BrickColor.Blue;
			Reflectance = 0.5;
			Transparency = 0.4;
			FormFactor = "Custom";
			Size = Vector3.new(3,3,3);
			Anchored = true;
			TopSurface = "Smooth";
			BottomSurface = "Smooth";
		})
end

for i=1, NumLinks do
	table.insert(Links, NewLink())
end

-- Mouse events

local IsDown = false

local function OnMouseMoved(Mouse)
	if IsDown then
		RecordStep(CFrame.new(Head.Position, Mouse.Hit.p) * Step)
	end

	Head.CFrame = GetStep(1)
	for i=2, NumLinks+1 do
		Links[i-1].CFrame = GetStep(i)
	end
end

local function OnMouseDown()
	IsDown = true
end

local function OnMouseUp()
	IsDown = false
end

local function KeyDown(Mouse, Key)

end

local function KeyUp(Mouse, Key)

end

-- Tool creation and management

local Hop;

if not script then -- We're being loadstring'd
	Hop = new("HopperBin", PlayerBackpack, HopperProps)
end

if not script.Parent:IsA("HopperBin") then
	Hop = new("HopperBin", PlayerBackpack, HopperProps)

	local Scr = script:Clone()
	Scr.Parent = Hop

	script:Destroy()
else
	if not Hop then
		Hop = script.Parent
	end

	Hop.Selected:connect(function(Mouse)
		Mouse.Button1Down:connect(OnMouseDown)
		Mouse.Button1Up:connect(OnMouseUp)

		-- Mouse.Idle and Mouse.Move fire in a continuous loop
		Mouse.Move:connect(function()
			OnMouseMoved(Mouse)
		end)
		Mouse.Idle:connect(function()
			OnMouseMoved(Mouse)
		end)

		Mouse.KeyDown:connect(function(Key)
			KeyDown(Mouse, Key)
		end)
		Mouse.KeyUp:connect(function(Key)
			KeyUp(Mouse, Key)
		end)
	end)
end