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

local LocalPlayer = Players.LocalPlayer

local DEFAULT_COLOR = Color3.fromRGB(50, 205, 50)
local KNIFE_COLOR   = Color3.fromRGB(220, 40, 40)
local GUN_COLOR     = Color3.fromRGB(40, 120, 255)

local FILL_ALPHA    = 1
local OUTLINE_ALPHA = 0

local HL_TAG = "_WH"
local BB_TAG = "_WBB"

local trackedData = {}

local weaponKeywords = {
	{ pattern = "gun",   priority = 2, color = GUN_COLOR   },
	{ pattern = "knife", priority = 1, color = KNIFE_COLOR },
}

local function detectWeaponColor(character, player)
	local best, bestPrio = nil, 0
	local function checkTool(tool)
		if not tool:IsA("Tool") then return end
		local lower = tool.Name:lower()
		for _, entry in ipairs(weaponKeywords) do
			if lower:find(entry.pattern) and entry.priority > bestPrio then
				bestPrio = entry.priority
				best = entry.color
			end
		end
	end
	for _, obj in ipairs(character:GetChildren()) do checkTool(obj) end
	local bp = player:FindFirstChildOfClass("Backpack")
	if bp then for _, obj in ipairs(bp:GetChildren()) do checkTool(obj) end end
	return best or DEFAULT_COLOR
end

local function getOrMakeHighlight(character)
	local h = character:FindFirstChild(HL_TAG)
	if h and h:IsA("Highlight") then return h end
	if h then h:Destroy() end
	local hl = Instance.new("Highlight")
	hl.Name = HL_TAG
	hl.Adornee = character
	hl.DepthMode = Enum.HighlightDepthMode.AlwaysOnTop
	hl.FillTransparency = FILL_ALPHA
	hl.OutlineTransparency = OUTLINE_ALPHA
	hl.FillColor = DEFAULT_COLOR
	hl.OutlineColor = DEFAULT_COLOR
	hl.Parent = character
	return hl
end

local function getOrMakeBillboard(character, playerName)
	local head = character:FindFirstChild("Head")
	if not head then return nil end

	local bb = head:FindFirstChild(BB_TAG)
	if bb and bb:IsA("BillboardGui") then
		return bb:FindFirstChild("NameLabel")
	end
	if bb then bb:Destroy() end

	local billboard = Instance.new("BillboardGui")
	billboard.Name = BB_TAG
	billboard.Adornee = head
	billboard.AlwaysOnTop = true
	billboard.Size = UDim2.new(0, 140, 0, 26)
	billboard.StudsOffset = Vector3.new(0, 2.6, 0)
	billboard.ResetOnSpawn = false
	billboard.Parent = head

	local label = Instance.new("TextLabel")
	label.Name = "NameLabel"
	label.Size = UDim2.new(1, 0, 1, 0)
	label.BackgroundTransparency = 1
	label.Text = playerName
	label.Font = Enum.Font.GothamBold
	label.TextSize = 13
	label.TextColor3 = DEFAULT_COLOR
	label.TextStrokeTransparency = 1
	label.TextScaled = false
	label.Parent = billboard

	return label
end

local function updatePlayer(player)
	if player == LocalPlayer then return end
	local character = player.Character
	if not character or not character:FindFirstChild("HumanoidRootPart") then return end

	local color = detectWeaponColor(character, player)

	local hl = getOrMakeHighlight(character)
	hl.OutlineColor = color
	hl.FillColor = color

	local label = getOrMakeBillboard(character, player.DisplayName)
	if label then
		label.TextColor3 = color
	end
end

local function hookCharacter(player, character)
	character:WaitForChild("HumanoidRootPart", 10)

	local conn = RunService.Heartbeat:Connect(function()
		if not character.Parent then return end
		updatePlayer(player)
	end)

	local prev = trackedData[player]
	if prev then
		if prev.conn then prev.conn:Disconnect() end
		if prev.character then
			local oldHl = prev.character:FindFirstChild(HL_TAG)
			if oldHl then oldHl:Destroy() end
			local oldHead = prev.character:FindFirstChild("Head")
			if oldHead then
				local oldBb = oldHead:FindFirstChild(BB_TAG)
				if oldBb then oldBb:Destroy() end
			end
		end
	end

	trackedData[player] = { conn = conn, character = character }

	character.AncestryChanged:Connect(function(_, parent)
		if not parent and trackedData[player] and trackedData[player].character == character then
			conn:Disconnect()
		end
	end)
end

local function hookPlayer(player)
	if player == LocalPlayer then return end
	if player.Character then task.spawn(hookCharacter, player, player.Character) end
	player.CharacterAdded:Connect(function(character)
		task.spawn(hookCharacter, player, character)
	end)
end

for _, player in ipairs(Players:GetPlayers()) do task.spawn(hookPlayer, player) end
Players.PlayerAdded:Connect(hookPlayer)

Players.PlayerRemoving:Connect(function(player)
	local data = trackedData[player]
	if not data then return end
	if data.conn then data.conn:Disconnect() end
	if data.character then
		local hl = data.character:FindFirstChild(HL_TAG)
		if hl then hl:Destroy() end
		local head = data.character:FindFirstChild("Head")
		if head then
			local bb = head:FindFirstChild(BB_TAG)
			if bb then bb:Destroy() end
		end
	end
	trackedData[player] = nil
end)