local Players = game:GetService("Players")
local TweenService = game:GetService("TweenService")

local LocalPlayer = Players.LocalPlayer
if not LocalPlayer then
	Players:GetPropertyChangedSignal("LocalPlayer"):Wait()
	LocalPlayer = Players.LocalPlayer
end

local function waitForChildOfClass(parent: Instance, class: string)
	local child = parent:FindFirstChildOfClass(class)
	while not child or child.ClassName ~= class do
		child = parent.ChildAdded:Wait()
	end
	return child
end

local PlayerGui = waitForChildOfClass(LocalPlayer, "PlayerGui")

local TOAST_OPEN_SIZE = UDim2.new(0, 326, 0, 58)
local TOAST_CLOSED_SIZE = UDim2.new(0, 80, 0, 58)
local TOAST_BACKGROUND_COLOR = Color3.fromRGB(32, 32, 32)
local TOAST_BACKGROUND_TRANS = 0.4
local TOAST_FOREGROUND_COLOR = Color3.fromRGB(200, 200, 200)
local TOAST_FOREGROUND_TRANS = 0

-- Convenient syntax for creating a tree of instanes
local function create(className: string)
	return function(props)
		local inst = Instance.new(className)
		local parent = props.Parent
		props.Parent = nil
		for name, val in pairs(props) do
			if type(name) == "string" then
				inst[name] = val
			else
				val.Parent = inst
			end
		end
		-- Only set parent after all other properties are initialized
		inst.Parent = parent
		return inst
	end
end

local initialized = false

local uiRoot: ScreenGui
local toast
local toastIcon
local toastUpperText
local toastLowerText

local function initializeUI()
	assert(not initialized)

	uiRoot = create("ScreenGui"){
		Name = "RbxCameraUI",
		AutoLocalize = false,
		Enabled = true,
		DisplayOrder = -1, -- Appears behind default developer UI
		IgnoreGuiInset = false,
		ResetOnSpawn = false,
		ZIndexBehavior = Enum.ZIndexBehavior.Sibling,

		create("ImageLabel"){
			Name = "Toast",
			Visible = false,
			AnchorPoint = Vector2.new(0.5, 0),
			BackgroundTransparency = 1,
			BorderSizePixel = 0,
			Position = UDim2.new(0.5, 0, 0, 8),
			Size = TOAST_CLOSED_SIZE,
			Image = "rbxasset://textures/ui/Camera/CameraToast9Slice.png",
			ImageColor3 = TOAST_BACKGROUND_COLOR,
			ImageRectSize = Vector2.new(6, 6),
			ImageTransparency = 1,
			ScaleType = Enum.ScaleType.Slice,
			SliceCenter = Rect.new(3, 3, 3, 3),
			ClipsDescendants = true,

			create("Frame"){
				Name = "IconBuffer",
				BackgroundTransparency = 1,
				BorderSizePixel = 0,
				Position = UDim2.new(0, 0, 0, 0),
				Size = UDim2.new(0, 80, 1, 0),

				create("ImageLabel"){
					Name = "Icon",
					AnchorPoint = Vector2.new(0.5, 0.5),
					BackgroundTransparency = 1,
					Position = UDim2.new(0.5, 0, 0.5, 0),
					Size = UDim2.new(0, 48, 0, 48),
					ZIndex = 2,
					Image = "rbxasset://textures/ui/Camera/CameraToastIcon.png",
					ImageColor3 = TOAST_FOREGROUND_COLOR,
					ImageTransparency = 1,
				}
			},

			create("Frame"){
				Name = "TextBuffer",
				BackgroundTransparency = 1,
				BorderSizePixel = 0,
				Position = UDim2.new(0, 80, 0, 0),
				Size = UDim2.new(1, -80, 1, 0),
				ClipsDescendants = true,

				create("TextLabel"){
					Name = "Upper",
					AnchorPoint = Vector2.new(0, 1),
					BackgroundTransparency = 1,
					Position = UDim2.new(0, 0, 0.5, 0),
					Size = UDim2.new(1, 0, 0, 19),
					Font = Enum.Font.GothamSemibold,
					Text = "Camera control enabled",
					TextColor3 = TOAST_FOREGROUND_COLOR,
					TextTransparency = 1,
					TextSize = 19,
					TextXAlignment = Enum.TextXAlignment.Left,
					TextYAlignment = Enum.TextYAlignment.Center,
				},

				create("TextLabel"){
					Name = "Lower",
					AnchorPoint = Vector2.new(0, 0),
					BackgroundTransparency = 1,
					Position = UDim2.new(0, 0, 0.5, 3),
					Size = UDim2.new(1, 0, 0, 15),
					Font = Enum.Font.Gotham,
					Text = "Right mouse button to toggle",
					TextColor3 = TOAST_FOREGROUND_COLOR,
					TextTransparency = 1,
					TextSize = 15,
					TextXAlignment = Enum.TextXAlignment.Left,
					TextYAlignment = Enum.TextYAlignment.Center,
				},
			},
		},

		Parent = PlayerGui,
	}

	toast = uiRoot.Toast
	toastIcon = toast.IconBuffer.Icon
	toastUpperText = toast.TextBuffer.Upper
	toastLowerText = toast.TextBuffer.Lower

	initialized = true
end

local CameraUI = {}

do
	-- Instantaneously disable the toast or enable for opening later on. Used when switching camera modes.
	function CameraUI.setCameraModeToastEnabled(enabled: boolean)
		if not enabled and not initialized then
			return
		end

		if not initialized then
			initializeUI()
		end

		toast.Visible = enabled
		if not enabled then
			CameraUI.setCameraModeToastOpen(false)
		end
	end

	local tweenInfo = TweenInfo.new(0.25, Enum.EasingStyle.Quad, Enum.EasingDirection.Out)

	-- Tween the toast in or out. Toast must be enabled with setCameraModeToastEnabled.
	function CameraUI.setCameraModeToastOpen(open: boolean)
		assert(initialized)

		TweenService:Create(toast, tweenInfo, {
			Size = open and TOAST_OPEN_SIZE or TOAST_CLOSED_SIZE,
			ImageTransparency = open and TOAST_BACKGROUND_TRANS or 1,
		}):Play()

		TweenService:Create(toastIcon, tweenInfo, {
			ImageTransparency = open and TOAST_FOREGROUND_TRANS or 1,
		}):Play()

		TweenService:Create(toastUpperText, tweenInfo, {
			TextTransparency = open and TOAST_FOREGROUND_TRANS or 1,
		}):Play()

		TweenService:Create(toastLowerText, tweenInfo, {
			TextTransparency = open and TOAST_FOREGROUND_TRANS or 1,
		}):Play()
	end
end

return CameraUI
