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

local BASE_SIZE = Vector3.new(10, 10, 10)   -- Base to hơn người 5 studs mỗi bên
local EXTRA_LENGTH = 8                      -- Dài hơn 4 studs → +8
local MAX_SIZE = Vector3.new(150, 150, 150) -- Nếu nhiều người thì full 150

local trackedTools = {}

local function updateHitboxes()
    trackedTools = {}
    
    for _, tool in ipairs(LocalPlayer.Backpack:GetChildren()) do
        if tool:IsA("Tool") then
            local hitbox = tool:FindFirstChild("Hitbox")
            if hitbox and hitbox:IsA("BasePart") then
                table.insert(trackedTools, hitbox)
            end
        end
    end
    
    if LocalPlayer.Character then
        for _, tool in ipairs(LocalPlayer.Character:GetChildren()) do
            if tool:IsA("Tool") then
                local hitbox = tool:FindFirstChild("Hitbox")
                if hitbox and hitbox:IsA("BasePart") then
                    table.insert(trackedTools, hitbox)
                end
            end
        end
    end
    
    if #trackedTools == 0 then return end
    
    local nearbyPlayers = {}
    local myRoot = LocalPlayer.Character and LocalPlayer.Character:FindFirstChild("HumanoidRootPart")
    if not myRoot then return end
    
    for _, plr in ipairs(Players:GetPlayers()) do
        if plr ~= LocalPlayer and plr.Character and plr.Character:FindFirstChild("HumanoidRootPart") then
            local dist = (plr.Character.HumanoidRootPart.Position - myRoot.Position).Magnitude
            if dist < 50 then
                table.insert(nearbyPlayers, plr.Character.HumanoidRootPart)
            end
        end
    end
    
    if #nearbyPlayers > 0 then
        local targetPos = myRoot.Position  -- default trung bình
        local totalPos = Vector3.new()
        
        for _, part in ipairs(nearbyPlayers) do
            totalPos += part.Position
        end
        targetPos = totalPos / #nearbyPlayers
        
        if #nearbyPlayers == 1 then
            local direction = (nearbyPlayers[1].Position - myRoot.Position).Unit
            targetPos = nearbyPlayers[1].Position + direction * 2  -- offset nhẹ về phía trước
        end
        
        local finalSize
        if #nearbyPlayers == 1 then
            finalSize = BASE_SIZE + Vector3.new(10, 10, EXTRA_LENGTH)
        else
            finalSize = MAX_SIZE
        end
        
        for _, hb in ipairs(trackedTools) do
            hb.Size = finalSize
            hb.Position = targetPos  -- Dời Hitbox tới vị trí trung bình/nhắm
            hb.Transparency = 0.7     -- Optional: thấy được để debug
            hb.CanCollide = false     -- Không cản đường
            print("Buff Hitbox: Size = " .. tostring(finalSize) .. " | Pos nhắm = " .. tostring(targetPos))
        end
    else
        for _, hb in ipairs(trackedTools) do
            hb.Size = Vector3.new(4, 4, 4)
            print("Không có player gần, reset Hitbox size nhỏ")
        end
    end
end

RunService.Heartbeat:Connect(function()
    if LocalPlayer.Character and LocalPlayer.Character:FindFirstChild("Humanoid") and LocalPlayer.Character.Humanoid.Health > 0 then
        updateHitboxes()
    end
end)

LocalPlayer.Backpack.ChildAdded:Connect(function(child)
    if child:IsA("Tool") then
        task.wait(0.1)
        updateHitboxes()
    end
end)

LocalPlayer.CharacterAdded:Connect(function()
    task.wait(1)
    updateHitboxes()
end)