--[[
    Enhanced ESP Script with performance optimizations and improved functionality
    Features:
    - Optimized refresh rate
    - Memory management
    - Error handling
    - Customizable colors
    - Configurable settings
    - Better visual formatting
]]

-- Services
local Players = game:GetService("Players")
local UserInputService = game:GetService("UserInputService")
local RunService = game:GetService("RunService")
local TweenService = game:GetService("TweenService")

-- Constants
local SETTINGS = {
    REFRESH_INTERVAL = 5,
    UPDATE_INTERVAL = 0.1,
    BASE_WALK_SPEED = 16,
    MAX_SPEED_INCREASE = 12,
    BILLBOARD_SIZE = Vector2.new(150, 60),
    BILLBOARD_OFFSET = Vector3.new(0, 2, 0),
    COLORS = {
        TEXT = Color3.fromRGB(0, 255, 0),
        STROKE = Color3.fromRGB(0, 0, 0),
        SELECTION = Color3.fromRGB(0, 255, 0),
        NOTIFICATION_BG = Color3.fromRGB(0, 0, 0),
        NOTIFICATION_TEXT = Color3.fromRGB(255, 255, 255)
    },
    FONT = Enum.Font.Garamond,
    TEXT_SIZES = {
        NAME = 14,
        INFO = 12,
        NOTIFICATION = 20
    },
    UNITS = {
        DISTANCE = "m"
    }
}

-- Cache
local Player = Players.LocalPlayer
local Character = Player.Character or Player.CharacterAdded:Wait()
local Humanoid = Character:WaitForChild("Humanoid")
local PlayerGui = Player:WaitForChild("PlayerGui")

-- State
local ESPState = {
    folder = workspace:FindFirstChild("Animals"),
    billboards = {},
    active = true,
    lastUpdate = 0,
    connections = {}
}

-- Utility Functions
local function cleanupConnections()
    for _, connection in ipairs(ESPState.connections) do
        if connection.Disconnect then
            connection:Disconnect()
        end
    end
    ESPState.connections = {}
end

local function formatNumber(number)
    return string.format("%.1f", number)
end

local function createLabel(properties)
    local label = Instance.new("TextLabel")
    for key, value in pairs(properties) do
        label[key] = value
    end
    return label
end

-- Core Functions
local function showNotification(message, duration)
    duration = duration or 1.5
    
    local notification = createLabel({
        Text = message,
        Size = UDim2.new(0, 200, 0, 50),
        Position = UDim2.new(0.5, -100, 0, 50),
        BackgroundTransparency = 0.5,
        BackgroundColor3 = SETTINGS.COLORS.NOTIFICATION_BG,
        TextColor3 = SETTINGS.COLORS.NOTIFICATION_TEXT,
        TextSize = SETTINGS.TEXT_SIZES.NOTIFICATION,
        Font = SETTINGS.FONT,
        TextStrokeTransparency = 0.5,
        TextStrokeColor3 = SETTINGS.COLORS.STROKE,
        Parent = PlayerGui
    })

    local tween = TweenService:Create(notification, 
        TweenInfo.new(duration, Enum.EasingStyle.Quad, Enum.EasingDirection.Out),
        {Position = UDim2.new(0.5, -100, 0, 0), TextTransparency = 1, BackgroundTransparency = 1}
    )
    
    tween:Play()
    task.delay(duration, function()
        notification:Destroy()
    end)
end

local function createBillboardGui(model)
    if not model:IsA("Model") or (not model.PrimaryPart and not model:FindFirstChild("HumanoidRootPart")) then
        return nil
    end

    local billboardGui = Instance.new("BillboardGui")
    billboardGui.Adornee = model.PrimaryPart or model:FindFirstChild("HumanoidRootPart")
    billboardGui.Size = UDim2.new(0, SETTINGS.BILLBOARD_SIZE.X, 0, SETTINGS.BILLBOARD_SIZE.Y)
    billboardGui.StudsOffset = SETTINGS.BILLBOARD_OFFSET
    billboardGui.AlwaysOnTop = true

    -- Name Label
    local nameLabel = createLabel({
        Text = model.Name,
        Size = UDim2.new(1, 0, 0.5, 0),
        BackgroundTransparency = 1,
        TextColor3 = SETTINGS.COLORS.TEXT,
        TextStrokeTransparency = 0,
        TextStrokeColor3 = SETTINGS.COLORS.STROKE,
        TextSize = SETTINGS.TEXT_SIZES.NAME,
        Font = SETTINGS.FONT,
        Parent = billboardGui
    })

    -- Distance Label
    local distanceLabel = createLabel({
        Size = UDim2.new(1, 0, 0.5, 0),
        Position = UDim2.new(0, 0, 0.5, 0),
        BackgroundTransparency = 1,
        TextColor3 = SETTINGS.COLORS.TEXT,
        TextStrokeTransparency = 0,
        TextStrokeColor3 = SETTINGS.COLORS.STROKE,
        TextSize = SETTINGS.TEXT_SIZES.INFO,
        Font = SETTINGS.FONT,
        Text = "Calculating...",
        Parent = billboardGui
    })

    -- Selection Box
    local selectionBox = Instance.new("SelectionBox")
    selectionBox.Adornee = billboardGui.Adornee
    selectionBox.LineThickness = 0.1
    selectionBox.SurfaceTransparency = 0.8
    selectionBox.Color3 = SETTINGS.COLORS.SELECTION
    selectionBox.Parent = model

    billboardGui.Parent = model
    return {
        gui = billboardGui,
        distanceLabel = distanceLabel,
        selectionBox = selectionBox,
        model = model
    }
end

local function refreshVisuals()
    -- Cleanup existing billboards
    for _, visualInfo in ipairs(ESPState.billboards) do
        if visualInfo.gui then visualInfo.gui:Destroy() end
        if visualInfo.selectionBox then visualInfo.selectionBox:Destroy() end
    end
    ESPState.billboards = {}

    -- Create new billboards
    if ESPState.folder then
        for _, model in ipairs(ESPState.folder:GetChildren()) do
            local billboard = createBillboardGui(model)
            if billboard then
                table.insert(ESPState.billboards, billboard)
            end
        end
    end
end

local function updateBillboards()
    if not ESPState.active or not Character.PrimaryPart then return end
    
    local currentTime = time()
    if currentTime - ESPState.lastUpdate < SETTINGS.UPDATE_INTERVAL then return end
    ESPState.lastUpdate = currentTime

    for _, visualInfo in ipairs(ESPState.billboards) do
        if visualInfo.model and visualInfo.model.PrimaryPart then
            local distance = (visualInfo.model.PrimaryPart.Position - Character.PrimaryPart.Position).Magnitude
            visualInfo.distanceLabel.Text = string.format("Distance: %s %s", formatNumber(distance), SETTINGS.UNITS.DISTANCE)
        end
    end
end

local function adjustSpeed(amount)
    local newSpeed = Humanoid.WalkSpeed + amount
    if newSpeed <= (SETTINGS.BASE_WALK_SPEED + SETTINGS.MAX_SPEED_INCREASE) and newSpeed >= 0 then
        Humanoid.WalkSpeed = newSpeed
        showNotification("Walk Speed: " .. math.floor(newSpeed))
    else
        showNotification("Speed limit reached!")
    end
end

local function toggleESP()
    ESPState.active = not ESPState.active
    for _, visualInfo in ipairs(ESPState.billboards) do
        if visualInfo.gui then
            visualInfo.gui.Enabled = ESPState.active
        end
        if visualInfo.selectionBox then
            visualInfo.selectionBox.Visible = ESPState.active
        end
    end
    showNotification("ESP " .. (ESPState.active and "Enabled" or "Disabled"))
end

-- Setup
local function initialize()
    -- Clean up existing connections
    cleanupConnections()

    -- Input handling
    table.insert(ESPState.connections, UserInputService.InputBegan:Connect(function(input, processed)
        if processed then return end
        
        if input.KeyCode == Enum.KeyCode.N then
            adjustSpeed(2)
        elseif input.KeyCode == Enum.KeyCode.B then
            adjustSpeed(-2)
        elseif input.KeyCode == Enum.KeyCode.Q then
            toggleESP()
        end
    end))

    -- Periodic refresh
    task.spawn(function()
        while task.wait(SETTINGS.REFRESH_INTERVAL) do
            if ESPState.active then
                refreshVisuals()
            end
        end
    end)

    -- Update loop
    table.insert(ESPState.connections, RunService.RenderStepped:Connect(updateBillboards))

    -- Initial setup
    refreshVisuals()
    showNotification("ESP Initialized")
end

-- Initialize on script load
initialize()

-- Cleanup on script end
game:BindToClose(function()
    cleanupConnections()
end)