--// Services
local Players = game:GetService("Players")
local UIS = game:GetService("UserInputService")
local RS = game:GetService("RunService")
local LP = Players.LocalPlayer
local Cam = workspace.CurrentCamera

--// State
local flying = false
local velocity = Vector3.zero
local speed = 50
local sensitivity = 0.002
local camRot = Vector2.new()
local con

--// Movement keys
local moveKeys = {
	W = true, A = true, S = true, D = true,
	Space = true, LeftControl = false
}

--// Input Begin
UIS.InputBegan:Connect(function(input, gp)
	if gp then return end
	if input.KeyCode == Enum.KeyCode.LeftShift then
		flying = not flying
		if flying then
			Cam.CameraType = Enum.CameraType.Scriptable
			camRot = Vector2.new(Cam.CFrame:ToOrientation())
			UIS.MouseBehavior = Enum.MouseBehavior.LockCenter
			UIS.MouseIconEnabled = false

			con = RS.RenderStepped:Connect(function(dt)
				local delta = UIS:GetMouseDelta()
				camRot = camRot + Vector2.new(-delta.Y, -delta.X) * sensitivity
				camRot = Vector2.new(math.clamp(camRot.X, -1.5, 1.5), camRot.Y)

				local rot = CFrame.Angles(0, camRot.Y, 0) * CFrame.Angles(camRot.X, 0, 0)
				local moveDir = Vector3.zero
				if moveKeys.W then moveDir += Vector3.new(0, 0, -1) end
				if moveKeys.S then moveDir += Vector3.new(0, 0, 1) end
				if moveKeys.A then moveDir += Vector3.new(-1, 0, 0) end
				if moveKeys.D then moveDir += Vector3.new(1, 0, 0) end
				if moveKeys.Space then moveDir += Vector3.new(0, 1, 0) end
				if moveKeys.LeftControl then moveDir += Vector3.new(0, -1, 0) end

				if moveDir.Magnitude > 0 then
					velocity = velocity:Lerp((rot * moveDir.Unit) * speed, 0.25)
				else
					velocity *= 0.85
				end

				Cam.CFrame = Cam.CFrame + velocity * dt
				Cam.CFrame = CFrame.new(Cam.CFrame.Position) * rot
			end)
		else
			if con then con:Disconnect() end
			Cam.CameraType = Enum.CameraType.Custom
			UIS.MouseBehavior = Enum.MouseBehavior.Default
			UIS.MouseIconEnabled = true
		end
	else
		local key = input.KeyCode.Name
		if moveKeys[key] ~= nil then
			moveKeys[key] = true
		end
	end
end)

--// Input End
UIS.InputEnded:Connect(function(input)
	local key = input.KeyCode.Name
	if moveKeys[key] ~= nil then
		moveKeys[key] = false
	end
end)