-- Player Vision Detection System
-- Detects when other players can see you (no walls blocking)

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

-- Configuration
local FOV_ANGLE = 90 -- Field of view in degrees (half angle, so total is 180°)
local MAX_VISION_DISTANCE = 100 -- Maximum distance they can see
local SCAN_INTERVAL = 0.1 -- How often to check (seconds)
local VISUALIZE = true -- Show debug visualization

-- Convert degrees to radians
local FOV_RADIANS = math.rad(FOV_ANGLE)

-- Store players who can currently see you
local playersWhoSeeYou = {}

-- Create GUI for displaying who sees you
local function createGUI()
	local screenGui = Instance.new("ScreenGui")
	screenGui.Name = "VisionDetectorGUI"
	screenGui.ResetOnSpawn = false
	screenGui.Parent = LocalPlayer:WaitForChild("PlayerGui")
	
	local frame = Instance.new("Frame")
	frame.Size = UDim2.new(0, 250, 0, 300)
	frame.Position = UDim2.new(1, -260, 0, 10)
	frame.BackgroundColor3 = Color3.fromRGB(30, 30, 30)
	frame.BackgroundTransparency = 0.3
	frame.BorderSizePixel = 0
	frame.Parent = screenGui
	
	local corner = Instance.new("UICorner")
	corner.CornerRadius = UDim.new(0, 8)
	corner.Parent = frame
	
	local title = Instance.new("TextLabel")
	title.Size = UDim2.new(1, -20, 0, 30)
	title.Position = UDim2.new(0, 10, 0, 5)
	title.BackgroundTransparency = 1
	title.Text = "Players Who See You:"
	title.TextColor3 = Color3.fromRGB(255, 255, 255)
	title.TextSize = 16
	title.Font = Enum.Font.GothamBold
	title.TextXAlignment = Enum.TextXAlignment.Left
	title.Parent = frame
	
	local listFrame = Instance.new("ScrollingFrame")
	listFrame.Size = UDim2.new(1, -20, 1, -45)
	listFrame.Position = UDim2.new(0, 10, 0, 40)
	listFrame.BackgroundTransparency = 1
	listFrame.BorderSizePixel = 0
	listFrame.ScrollBarThickness = 6
	listFrame.Parent = frame
	
	local listLayout = Instance.new("UIListLayout")
	listLayout.SortOrder = Enum.SortOrder.Name
	listLayout.Padding = UDim.new(0, 5)
	listLayout.Parent = listFrame
	
	return listFrame
end

local listFrame = createGUI()

-- Update GUI with current players
local function updateGUI()
	-- Clear existing labels
	for _, child in ipairs(listFrame:GetChildren()) do
		if child:IsA("TextLabel") then
			child:Destroy()
		end
	end
	
	-- Create labels for each player who sees you
	for playerName, data in pairs(playersWhoSeeYou) do
		local label = Instance.new("TextLabel")
		label.Size = UDim2.new(1, 0, 0, 25)
		label.BackgroundColor3 = Color3.fromRGB(200, 50, 50)
		label.BackgroundTransparency = 0.5
		label.Text = playerName .. " (" .. math.floor(data.distance) .. " studs)"
		label.TextColor3 = Color3.fromRGB(255, 255, 255)
		label.TextSize = 14
		label.Font = Enum.Font.Gotham
		label.Parent = listFrame
		
		local corner = Instance.new("UICorner")
		corner.CornerRadius = UDim.new(0, 4)
		corner.Parent = label
	end
end

-- Check if a point is within a cone
local function isInCone(observerPos, observerLookVector, targetPos, fovRadians, maxDistance)
	local toTarget = targetPos - observerPos
	local distance = toTarget.Magnitude
	
	-- Check distance first
	if distance > maxDistance then
		return false, distance
	end
	
	-- Normalize the vector
	local directionToTarget = toTarget.Unit
	
	-- Calculate the angle between look vector and direction to target
	local dotProduct = observerLookVector:Dot(directionToTarget)
	local angleRadians = math.acos(math.clamp(dotProduct, -1, 1))
	
	-- Check if within FOV
	return angleRadians <= fovRadians, distance
end

-- Perform raycast to check for walls
local function hasLineOfSight(fromPos, toPos, ignoreList)
	local direction = toPos - fromPos
	local distance = direction.Magnitude
	
	local raycastParams = RaycastParams.new()
	raycastParams.FilterDescendantsInstances = ignoreList
	raycastParams.FilterType = Enum.RaycastFilterType.Exclude
	raycastParams.IgnoreWater = true
	
	local result = workspace:Raycast(fromPos, direction, raycastParams)
	
	-- If no hit, or hit is very close to target position, line of sight is clear
	if not result then
		return true
	end
	
	-- Check if we hit something before reaching the target
	local hitDistance = (result.Position - fromPos).Magnitude
	return hitDistance >= distance - 2 -- Small tolerance
end

-- Visualize FOV cone (for debugging)
local visualParts = {}
local function visualizeCone(character, canSeeLocalPlayer)
	if not VISUALIZE then return end
	
	-- Clear old visualization for this character
	local charName = character.Name
	if visualParts[charName] then
		for _, part in ipairs(visualParts[charName]) do
			part:Destroy()
		end
	end
	visualParts[charName] = {}
	
	local head = character:FindFirstChild("Head")
	if not head then return end
	
	-- Create a cone visualization
	local cone = Instance.new("Part")
	cone.Shape = Enum.PartType.Block
	cone.Size = Vector3.new(0.5, 0.5, MAX_VISION_DISTANCE / 2)
	cone.CFrame = head.CFrame * CFrame.new(0, 0, -MAX_VISION_DISTANCE / 4)
	cone.Color = canSeeLocalPlayer and Color3.fromRGB(255, 0, 0) or Color3.fromRGB(100, 100, 255)
	cone.Transparency = 0.7
	cone.CanCollide = false
	cone.Anchored = true
	cone.Material = Enum.Material.Neon
	cone.Parent = workspace
	
	table.insert(visualParts[charName], cone)
	
	-- Auto-destroy after a short time
	task.delay(SCAN_INTERVAL + 0.05, function()
		if cone and cone.Parent then
			cone:Destroy()
		end
	end)
end

-- Main detection function
local function checkVision()
	local localChar = LocalPlayer.Character
	if not localChar then return end
	
	local localRoot = localChar:FindFirstChild("HumanoidRootPart")
	local localHead = localChar:FindFirstChild("Head")
	if not localRoot or not localHead then return end
	
	local localPos = localHead.Position
	
	-- Clear previous detections
	playersWhoSeeYou = {}
	
	-- Check each other player
	for _, player in ipairs(Players:GetPlayers()) do
		if player ~= LocalPlayer then
			local char = player.Character
			if char then
				local humanoid = char:FindFirstChildOfClass("Humanoid")
				local head = char:FindFirstChild("Head")
				local root = char:FindFirstChild("HumanoidRootPart")
				
				if humanoid and humanoid.Health > 0 and head and root then
					-- Get the direction the player is facing
					local lookVector = root.CFrame.LookVector
					local observerPos = head.Position
					
					-- Check if local player is in their FOV cone
					local inCone, distance = isInCone(observerPos, lookVector, localPos, FOV_RADIANS, MAX_VISION_DISTANCE)
					
					if inCone then
						-- Check line of sight (no walls)
						local ignoreList = {localChar, char}
						local hasLOS = hasLineOfSight(observerPos, localPos, ignoreList)
						
						if hasLOS then
							playersWhoSeeYou[player.Name] = {
								distance = distance,
								player = player
							}
							visualizeCone(char, true)
						else
							visualizeCone(char, false)
						end
					else
						visualizeCone(char, false)
					end
				end
			end
		end
	end
	
	updateGUI()
end

-- Run the detection loop
local lastScan = 0
RunService.Heartbeat:Connect(function()
	local now = tick()
	if now - lastScan >= SCAN_INTERVAL then
		lastScan = now
		checkVision()
	end
end)

-- Clean up visualizations when players leave
Players.PlayerRemoving:Connect(function(player)
	if visualParts[player.Name] then
		for _, part in ipairs(visualParts[player.Name]) do
			part:Destroy()
		end
		visualParts[player.Name] = nil
	end
end)

print("Vision Detection System Activated!")
print("Players who can see you will appear in the top-right GUI")
print("Red cones = Can see you | Blue cones = Cannot see you")