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

local player = Players.LocalPlayer
local camera = workspace.CurrentCamera

-- Configuration
local predictionIntensity = 1.2 
local isAiming = false 
local lockedTarget = nil

-- Function to find target
local function getClosestPlayer()
    local closest = nil
    local shortestDist = math.huge
    local mousePos = UserInputService:GetMouseLocation()

    for _, p in pairs(Players:GetPlayers()) do
        if p ~= player and p.Character and p.Character:FindFirstChild("Head") and p.Character:FindFirstChild("Humanoid") then
            if p.Character.Humanoid.Health > 0 then
                local pos, onScreen = camera:WorldToViewportPoint(p.Character.Head.Position)
                if onScreen then
                    local dist = (Vector2.new(pos.X, pos.Y) - mousePos).Magnitude
                    if dist < shortestDist then
                        closest = p
                        shortestDist = dist
                    end
                end
            end
        end
    end
    return closest
end

local function getPing()
    local success, ping = pcall(function()
        return Stats.Network.ServerStatsItem["Data Ping"]:GetValue() / 1000
    end)
    return success and ping or 0.05
end

-- UI and Input Setup
local function InitializeAimlock()
    local screenGui = Instance.new("ScreenGui", player:WaitForChild("PlayerGui"))
    screenGui.Name = "AimLockGui"
    
    local toggleButton = Instance.new("TextButton", screenGui)
    toggleButton.Size = UDim2.new(0, 150, 0, 50)
    toggleButton.Position = UDim2.new(0.5, -75, 0.8, 0)
    toggleButton.Text = "Aimlock: OFF"
    toggleButton.BackgroundColor3 = Color3.fromRGB(200, 0, 0)
    toggleButton.TextColor3 = Color3.fromRGB(255, 255, 255)

    local function toggleAim()
        if not isAiming then
            lockedTarget = getClosestPlayer()
            if lockedTarget then
                isAiming = true
                toggleButton.Text = "Aimlock: ON (" .. lockedTarget.Name .. ")"
                toggleButton.BackgroundColor3 = Color3.fromRGB(0, 180, 0)
                if player.Character and player.Character:FindFirstChild("Humanoid") then
                    player.Character.Humanoid.AutoRotate = false
                end
            end
        else
            isAiming = false
            lockedTarget = nil
            toggleButton.Text = "Aimlock: OFF"
            toggleButton.BackgroundColor3 = Color3.fromRGB(200, 0, 0)
            if player.Character and player.Character:FindFirstChild("Humanoid") then
                player.Character.Humanoid.AutoRotate = true
            end
        end
    end

    toggleButton.MouseButton1Click:Connect(toggleAim)
    
    -- Using a unique name for input to prevent multiple connections
    UserInputService.InputBegan:Connect(function(input, processed)
        if processed then return end
        if input.UserInputType == Enum.UserInputType.MouseButton2 then
            toggleAim()
        end
    end)
end

-- Main Loop (Kept outside to avoid re-binding issues)
RunService:BindToRenderStep("HardLock", Enum.RenderPriority.Camera.Value + 1, function()
    if isAiming and lockedTarget and lockedTarget.Character then
        local tHead = lockedTarget.Character:FindFirstChild("Head")
        local tRoot = lockedTarget.Character:FindFirstChild("HumanoidRootPart")
        local tHum = lockedTarget.Character:FindFirstChild("Humanoid")
        
        local char = player.Character
        local root = char and char:FindFirstChild("HumanoidRootPart")

        -- Check if target is still valid/alive
        if tHead and tRoot and tHum and tHum.Health > 0 and root then
            local ping = getPing()
            local predictedPos = tHead.Position + (tRoot.Velocity * ping * predictionIntensity)
            
            camera.CFrame = CFrame.lookAt(camera.CFrame.Position, predictedPos)
            
            -- Rotate Character
            local flatLookPos = Vector3.new(predictedPos.X, root.Position.Y, predictedPos.Z)
            root.CFrame = CFrame.lookAt(root.Position, flatLookPos)
        else
            -- Target died or player died, reset state
            isAiming = false
            lockedTarget = nil
        end
    end
end)

-- Initial Run
InitializeAimlock()
-- Note: We don't need CharacterAdded for the UI because ScreenGui.ResetOnSpawn is true by default