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

local Camera = Workspace.CurrentCamera
local LocalPlayer = Players.LocalPlayer

-- Configuration
local ESPEnabled = true
local ESPColor = Color3.new(1, 0, 0) -- Red for boxes
local ESPThickness = 1

local activeDrawings = {}

-- Helper function to create a player's visual elements (Box + Health Bar)
local function createVisuals()
    local visuals = {}
    
    -- Main ESP Box
    visuals.Box = Drawing.new("Square")
    visuals.Box.Visible = false
    visuals.Box.Color = ESPColor
    visuals.Box.Thickness = ESPThickness
    visuals.Box.Filled = false
    
    -- Health Bar Background (Outline)
    visuals.HealthBarBg = Drawing.new("Line")
    visuals.HealthBarBg.Visible = false
    visuals.HealthBarBg.Color = Color3.new(0, 0, 0)
    visuals.HealthBarBg.Thickness = 3
    
    -- Health Bar Fill (Dynamic)
    visuals.HealthBar = Drawing.new("Line")
    visuals.HealthBar.Visible = false
    visuals.HealthBar.Color = Color3.new(0, 1, 0) -- Green
    visuals.HealthBar.Thickness = 1
    
    return visuals
end

-- Helper function to clean up a player's drawings
local function removeVisuals(player)
    if activeDrawings[player] then
        activeDrawings[player].Box:Remove()
        activeDrawings[player].HealthBarBg:Remove()
        activeDrawings[player].HealthBar:Remove()
        activeDrawings[player] = nil
    end
end

-- Initialize tracking for existing players
for _, player in ipairs(Players:GetPlayers()) do
    if player ~= LocalPlayer then
        activeDrawings[player] = createVisuals()
    end
end

-- Handle new players joining
Players.PlayerAdded:Connect(function(player)
    if player ~= LocalPlayer then
        activeDrawings[player] = createVisuals()
    end
end)

-- Handle players leaving (cleanup memory)
Players.PlayerRemoving:Connect(function(player)
    removeVisuals(player)
end)

-- Centralized render loop (runs every frame)
RunService.RenderStepped:Connect(function()
    if not ESPEnabled then
        for _, visuals in pairs(activeDrawings) do
            visuals.Box.Visible = false
            visuals.HealthBarBg.Visible = false
            visuals.HealthBar.Visible = false
        end
        return
    end

    for player, visuals in pairs(activeDrawings) do
        local character = player.Character
        local rootPart = character and character:FindFirstChild("HumanoidRootPart")
        local humanoid = character and character:FindFirstChildOfClass("Humanoid")
        
        -- Verify character validity and life state
        if character and rootPart and humanoid and humanoid.Health > 0 then
            -- Project 3D world position to 2D screen space (Z represents distance/depth)
            local vector, onScreen = Camera:WorldToViewportPoint(rootPart.Position)
            
            if onScreen then
                -- Distance-based sizing: Scale inversely with depth (vector.Z)
                local distance = vector.Z
                local boxHeight = math.clamp(2500 / distance, 15, 800)
                local boxWidth = boxHeight * 0.6
                
                local boxX = vector.X - (boxWidth / 2)
                local boxY = vector.Y - (boxHeight / 2)
                
                -- Update main box
                visuals.Box.Size = Vector2.new(boxWidth, boxHeight)
                visuals.Box.Position = Vector2.new(boxX, boxY)
                visuals.Box.Visible = true
                
                -- Health Bar Calculations
                local healthPercent = math.clamp(humanoid.Health / humanoid.MaxHealth, 0, 1)
                local currentHealthHeight = boxHeight * healthPercent
                
                -- Position health bar just to the left of the box
                local barX = boxX - 6
                local barTopY = boxY
                local barBottomY = boxY + boxHeight
                
                -- Update Health Bar Background (full height)
                visuals.HealthBarBg.From = Vector2.new(barX, barBottomY)
                visuals.HealthBarBg.To = Vector2.new(barX, barTopY)
                visuals.HealthBarBg.Visible = true
                
                -- Update Health Bar Fill (scaled by health percentage, starting from bottom)
                visuals.HealthBar.From = Vector2.new(barX, barBottomY)
                visuals.HealthBar.To = Vector2.new(barX, barBottomY - currentHealthHeight)
                -- Optional: Shift color from green to red as health drops
                visuals.HealthBar.Color = Color3.new(1 - healthPercent, healthPercent, 0)
                visuals.HealthBar.Visible = true
            else
                visuals.Box.Visible = false
                visuals.HealthBarBg.Visible = false
                visuals.HealthBar.Visible = false
            end
        else
            visuals.Box.Visible = false
            visuals.HealthBarBg.Visible = false
            visuals.HealthBar.Visible = false
        end
    end
end)

-- Toggle ESP with the F9 key
UserInputService.InputBegan:Connect(function(input, gameProcessed)
    if not gameProcessed and input.KeyCode == Enum.KeyCode.F9 then
        ESPEnabled = not ESPEnabled
        if not ESPEnabled then
            for _, visuals in pairs(activeDrawings) do
                visuals.Box.Visible = false
                visuals.HealthBarBg.Visible = false
                visuals.HealthBar.Visible = false
            end
        end
    end
end)