local players = game:GetService("Players")
local runService = game:GetService("RunService")
local userInputService = game:GetService("UserInputService")

local localPlayer = players.LocalPlayer
local character = localPlayer.Character or localPlayer.CharacterAdded:Wait()

local root = character:WaitForChild("HumanoidRootPart")
local humanoid = character:WaitForChild("Humanoid")
local camera = workspace.CurrentCamera

local iconOff = "rbxassetid://77288664952024"
local iconOn = "rbxassetid://140416355442805"

local cursorImg = "rbxasset://textures/MouseLockedCursor.png"

local isTouchDevice = userInputService.TouchEnabled

local screenGui = Instance.new("ScreenGui")
screenGui.Name = "shiftlockgui"
screenGui.ResetOnSpawn = false
screenGui.ZIndexBehavior = Enum.ZIndexBehavior.Sibling
screenGui.IgnoreGuiInset = true
screenGui.Parent = localPlayer:WaitForChild("PlayerGui")

local customIconId = ""
local customCursorId = ""

if customIconId ~= "" then
	iconOff = customIconId
	iconOn = customIconId
end

if customCursorId ~= "" then
	cursorImg = customCursorId
end

local buttonPosition = UDim2.new(0.86, 0, 0.93, 0)
local buttonSize = UDim2.new(0, 44, 0, 44)

local button = Instance.new("ImageButton")
button.Name = "shiftlockbutton"
button.Size = buttonSize
button.Position = buttonPosition
button.AnchorPoint = Vector2.new(0.5, 0.5)
button.Image = iconOff
button.BackgroundTransparency = 1
button.BorderSizePixel = 0
button.ImageRectSize = Vector2.new(0, 0)
button.Visible = isTouchDevice
button.Parent = screenGui

local cursorSize = UDim2.new(0, 25, 0, 25)

local cursor = Instance.new("ImageLabel")
cursor.Name = "shiftlockcursor"
cursor.AnchorPoint = Vector2.new(0.5, 0.5)
cursor.Position = UDim2.new(0.5, 0, 0.5, 0)
cursor.Size = cursorSize
cursor.BackgroundTransparency = 1
cursor.BorderSizePixel = 0
cursor.ScaleType = Enum.ScaleType.Fit
cursor.Image = cursorImg
cursor.Visible = false
cursor.Parent = screenGui

local shiftLockActive = false
local renderConnection

local shoulderOffset = CFrame.new(1.7, 0, 0)
local maxLength = 999999999

local function updateButton(state)
	button.Image = state and iconOn or iconOff
end

local function getFacingCFrame()
	return CFrame.new(
		root.Position,
		Vector3.new(
			root.Position.X + camera.CFrame.LookVector.X * maxLength,
			root.Position.Y,
			root.Position.Z + camera.CFrame.LookVector.Z * maxLength
		)
	)
end

local function enableShiftLock()
	humanoid.AutoRotate = false
	updateButton(true)

	userInputService.MouseBehavior = Enum.MouseBehavior.LockCenter
	userInputService.MouseIconEnabled = false

	cursor.Visible = true

	renderConnection = runService.RenderStepped:Connect(function()
		root.CFrame = getFacingCFrame()
		camera.CFrame = camera.CFrame * shoulderOffset

		camera.Focus = CFrame.fromMatrix(
			camera.Focus.Position,
			camera.CFrame.RightVector,
			camera.CFrame.UpVector
		) * shoulderOffset
	end)
end

local function disableShiftLock()
	humanoid.AutoRotate = true
	updateButton(false)

	userInputService.MouseBehavior = Enum.MouseBehavior.Default
	userInputService.MouseIconEnabled = true

	cursor.Visible = false

	if renderConnection then
		renderConnection:Disconnect()
		renderConnection = nil
	end
end

local function toggleShiftLock()
	shiftLockActive = not shiftLockActive

	if shiftLockActive then
		enableShiftLock()
	else
		disableShiftLock()
	end
end

button.MouseButton1Click:Connect(toggleShiftLock)

localPlayer.CharacterAdded:Connect(function(newCharacter)
	character = newCharacter
	root = newCharacter:WaitForChild("HumanoidRootPart")
	humanoid = newCharacter:WaitForChild("Humanoid")

	if renderConnection then
		renderConnection:Disconnect()
		renderConnection = nil
	end

	shiftLockActive = false
	updateButton(false)

	cursor.Visible = false

	userInputService.MouseBehavior = Enum.MouseBehavior.Default
	userInputService.MouseIconEnabled = true
end)

players.PlayerRemoving:Connect(function(leavingPlayer)
	if leavingPlayer == localPlayer and shiftLockActive then
		disableShiftLock()
	end
end)