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

local tracked = {}

local BAR_WIDTH_PX = 130
local BAR_HEIGHT_PX = 14
local BAR_Y_OFFSET = 2.2

local COLOR_BG = Color3.fromRGB(15,15,20)
local COLOR_HP = Color3.fromRGB(0,220,220)
local COLOR_DAMAGE = Color3.fromRGB(255,70,70)
local COLOR_TEXT = Color3.fromRGB(255,255,255)

local function makeBar(model)
	if tracked[model] then
		return
	end

	local root = model:FindFirstChild("HumanoidRootPart")
	local humanoid = model:FindFirstChildOfClass("Humanoid")

	if not root or not humanoid then
		return
	end

	local bb = Instance.new("BillboardGui")
	bb.Name = "SF2HealthBar"
	bb.Adornee = root
	bb.Size = UDim2.fromOffset(BAR_WIDTH_PX, BAR_HEIGHT_PX)
	bb.StudsOffset = Vector3.new(0, BAR_Y_OFFSET, 0)
	bb.AlwaysOnTop = true
	bb.LightInfluence = 0
	bb.MaxDistance = 100
	bb.Parent = root

	local bg = Instance.new("Frame")
	bg.Size = UDim2.fromScale(1,1)
	bg.BackgroundColor3 = COLOR_BG
	bg.BorderSizePixel = 0
	bg.Parent = bb

	local bgCorner = Instance.new("UICorner")
	bgCorner.CornerRadius = UDim.new(0,5)
	bgCorner.Parent = bg

	local clip = Instance.new("Frame")
	clip.Size = UDim2.fromScale(1,1)
	clip.BackgroundTransparency = 1
	clip.BorderSizePixel = 0
	clip.ClipsDescendants = true
	clip.Parent = bg

	local clipCorner = Instance.new("UICorner")
	clipCorner.CornerRadius = UDim.new(0,5)
	clipCorner.Parent = clip

	local damageFill = Instance.new("Frame")
	damageFill.Size = UDim2.fromScale(1,1)
	damageFill.BackgroundColor3 = COLOR_DAMAGE
	damageFill.BorderSizePixel = 0
	damageFill.Parent = clip

	local hpFill = Instance.new("Frame")
	hpFill.Size = UDim2.fromScale(1,1)
	hpFill.BackgroundColor3 = COLOR_HP
	hpFill.BorderSizePixel = 0
	hpFill.Parent = clip

	local shine = Instance.new("Frame")
	shine.Size = UDim2.new(1,0,0,2)
	shine.BackgroundColor3 = Color3.new(1,1,1)
	shine.BackgroundTransparency = 0.75
	shine.BorderSizePixel = 0
	shine.Parent = hpFill

	local txt = Instance.new("TextLabel")
	txt.Size = UDim2.fromScale(1,1)
	txt.BackgroundTransparency = 1
	txt.Font = Enum.Font.GothamBold
	txt.TextScaled = true
	txt.TextColor3 = COLOR_TEXT
	txt.TextStrokeTransparency = 0
	txt.ZIndex = 5
	txt.Parent = bb

	local lastHealth = humanoid.Health

	local DAMAGE_DELAY = 1.2
	local DAMAGE_DRAIN_TIME = 0.9

	local damageToken = 0

	tracked[model] = {
		gui = bb
	}

	local function update()
		if not model.Parent then
			return
		end

		local maxHealth = math.max(humanoid.MaxHealth,1)
		local health = math.max(humanoid.Health,0)

		local ratio = health / maxHealth

		txt.Text = string.format(
			"%d / %d",
			math.floor(health),
			math.floor(maxHealth)
		)

		hpFill.Size = UDim2.new(ratio,0,1,0)

		if health < lastHealth then
			damageToken += 1

			local myToken = damageToken
			local targetRatio = ratio

			task.spawn(function()
				task.wait(DAMAGE_DELAY)

				if myToken ~= damageToken then
					return
				end

				if damageFill.Parent then
					damageFill:TweenSize(
						UDim2.new(targetRatio,0,1,0),
						Enum.EasingDirection.Out,
						Enum.EasingStyle.Quint,
						DAMAGE_DRAIN_TIME,
						true
					)
				end
			end)

		elseif health > lastHealth then
			damageToken += 1

			hpFill.Size = UDim2.new(ratio,0,1,0)
			damageFill.Size = UDim2.new(ratio,0,1,0)
		end

		lastHealth = health
	end

	update()

	humanoid.HealthChanged:Connect(update)

	model.AncestryChanged:Connect(function()
		if not model.Parent then
			if tracked[model] then
				tracked[model].gui:Destroy()
				tracked[model] = nil
			end
		end
	end)
end

local function scanModel(model)
	if tracked[model] then
		return
	end

	local humanoid = model:FindFirstChildOfClass("Humanoid")
	local root = model:FindFirstChild("HumanoidRootPart")

	if humanoid and root then
		makeBar(model)
	end
end

for _, player in ipairs(Players:GetPlayers()) do
	local function onCharacter(character)
		task.wait(0.5)
		scanModel(character)
	end

	if player.Character then
		onCharacter(player.Character)
	end

	player.CharacterAdded:Connect(onCharacter)
end

Players.PlayerAdded:Connect(function(player)
	player.CharacterAdded:Connect(function(character)
		task.wait(0.5)
		scanModel(character)
	end)
end)

for _, obj in ipairs(workspace:GetDescendants()) do
	if obj:IsA("Model")
		and obj:FindFirstChildOfClass("Humanoid")
		and obj:FindFirstChild("HumanoidRootPart") then

		if not Players:GetPlayerFromCharacter(obj) then
			scanModel(obj)
		end
	end
end

workspace.DescendantAdded:Connect(function(obj)
	if not obj:IsA("Model") then
		return
	end

	task.wait(0.5)

	if obj:FindFirstChildOfClass("Humanoid")
		and obj:FindFirstChild("HumanoidRootPart") then

		if not Players:GetPlayerFromCharacter(obj) then
			scanModel(obj)
		end
	end
end)