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

local player = Players.LocalPlayer

local flying = false
local speed = 65

-- movement state
local move = { forward = false, back = false, left = false, right = false, up = false, down = false }

-- references that will be (re)created per character
local hrp, hum
local bv, bg

local function cleanupBodyMovers()
    if bv and bv.Parent then bv:Destroy() end
    if bg and bg.Parent then bg:Destroy() end
    bv = nil
    bg = nil
end

local function createBodyMovers(parent)
    cleanupBodyMovers()

    bv = Instance.new("BodyVelocity")
    bv.MaxForce = Vector3.new(0,0,0)
    bv.Velocity = Vector3.new(0,0,0)
    bv.P = 1250
    bv.Parent = parent

    bg = Instance.new("BodyGyro")
    bg.MaxTorque = Vector3.new(0,0,0)
    bg.P = 9000
    bg.CFrame = workspace.CurrentCamera.CFrame
    bg.Parent = parent
end

local function onCharacterAdded(character)
    -- wait for required parts
    hrp = character:FindFirstChild("HumanoidRootPart") or character:WaitForChild("HumanoidRootPart", 5)
    hum = character:FindFirstChildOfClass("Humanoid") or character:WaitForChild("Humanoid", 5)

    if not hrp or not hum then
        warn("Flight script: couldn't find HumanoidRootPart or Humanoid on character.")
        return
    end

    createBodyMovers(hrp)
    flying = false
    hum.PlatformStand = false
    print("Flight script: character ready.")
end

-- attach to current character or wait
if player.Character and player.Character.Parent then
    onCharacterAdded(player.Character)
end
player.CharacterAdded:Connect(onCharacterAdded)

-- input handling
UIS.InputBegan:Connect(function(input, gameProcessed)
    if gameProcessed then return end
    local kc = input.KeyCode
    if kc == Enum.KeyCode.E then
        if not hrp or not hum then
            warn("Flight script: character not ready yet.")
            return
        end

        flying = not flying
        if flying then
            hum.PlatformStand = true
            if bv then bv.MaxForce = Vector3.new(5e5,5e5,5e5) end
            if bg then bg.MaxTorque = Vector3.new(5e5,5e5,5e5) end
            print("Flight enabled")
        else
            hum.PlatformStand = false
            if bv then bv.MaxForce = Vector3.new(0,0,0); bv.Velocity = Vector3.new(0,0,0) end
            if bg then bg.MaxTorque = Vector3.new(0,0,0) end
            print("Flight disabled")
        end
    end

    -- movement keys
    if kc == Enum.KeyCode.W then move.forward = true end
    if kc == Enum.KeyCode.S then move.back = true end
    if kc == Enum.KeyCode.A then move.left = true end
    if kc == Enum.KeyCode.D then move.right = true end
    if kc == Enum.KeyCode.Space then move.up = true end
    if kc == Enum.KeyCode.LeftControl then move.down = true end
end)

UIS.InputEnded:Connect(function(input)
    local kc = input.KeyCode
    if kc == Enum.KeyCode.W then move.forward = false end
    if kc == Enum.KeyCode.S then move.back = false end
    if kc == Enum.KeyCode.A then move.left = false end
    if kc == Enum.KeyCode.D then move.right = false end
    if kc == Enum.KeyCode.Space then move.up = false end
    if kc == Enum.KeyCode.LeftControl then move.down = false end
end)

-- main update loop
RunService.RenderStepped:Connect(function()
    if not flying then return end
    if not hrp or not bv or not bg then return end

    local cam = workspace.CurrentCamera
    local dir = Vector3.new(0,0,0)

    if move.forward then dir = dir + cam.CFrame.LookVector end
    if move.back    then dir = dir - cam.CFrame.LookVector end
    if move.left    then dir = dir - cam.CFrame.RightVector end
    if move.right   then dir = dir + cam.CFrame.RightVector end
    if move.up      then dir = dir + Vector3.new(0,1,0) end
    if move.down    then dir = dir - Vector3.new(0,1,0) end

    if dir.Magnitude > 0 then
        dir = dir.Unit * speed
    else
        dir = Vector3.new(0,0,0)
    end

    -- apply velocity and align orientation with camera
    bv.Velocity = dir
    bg.CFrame = cam.CFrame
end)

-- cleanup on teleport / leave
player.OnTeleport:Connect(function(state)
    cleanupBodyMovers()
end)