local INPUT_CHARACTER_WHEEL = 19
local INPUT_VEH_ACCELERATE = 71
local INPUT_VEH_DUCK = 73

local function IsNitroControlPressed()
  if not IsInputDisabled(2) then
    DisableControlAction(2, INPUT_VEH_DUCK)
    return IsDisabledControlPressed(2, INPUT_VEH_DUCK)
  end

  return IsControlPressed(0, INPUT_CHARACTER_WHEEL)
end

local function IsDrivingControlPressed()
  return IsControlPressed(0, INPUT_VEH_ACCELERATE)
end

local function NitroLoop(lastVehicle)
  local player = PlayerPedId()
  local vehicle = GetVehiclePedIsIn(player)
  local driver = GetPedInVehicleSeat(vehicle, -1)

  if lastVehicle ~= 0 and lastVehicle ~= vehicle then
    SetVehicleNitroBoostEnabled(lastVehicle, false)
    SetVehicleLightTrailEnabled(lastVehicle, false)
    SetVehicleNitroPurgeEnabled(lastVehicle, false)
    TriggerServerEvent('nitro:__sync', false, false, true)
  end

  if vehicle == 0 or driver ~= player then
    return 0
  end

  local model = GetEntityModel(vehicle)

  if not IsThisModelACar(model) or IsVehicleElectric(vehicle) then
    return 0
  end

  local isEnabled = IsNitroControlPressed()
  local isDriving = IsDrivingControlPressed()
  local isRunning = GetIsVehicleEngineRunning(vehicle)
  local isBoosting = IsVehicleNitroBoostEnabled(vehicle)
  local isPurging = IsVehicleNitroPurgeEnabled(vehicle)
  local isFueled = GetNitroFuelLevel(vehicle) > 0

  if isRunning and isEnabled and isFueled then
    if isDriving then
      if not isBoosting then
        SetVehicleNitroBoostEnabled(vehicle, true)
        SetVehicleLightTrailEnabled(vehicle, true)
        SetVehicleNitroPurgeEnabled(vehicle, false)
        TriggerServerEvent('nitro:__sync', true, false, false)
      end
    else
      if not isPurging then
        SetVehicleNitroBoostEnabled(vehicle, false)
        SetVehicleLightTrailEnabled(vehicle, false)
        SetVehicleNitroPurgeEnabled(vehicle, true)
        TriggerServerEvent('nitro:__sync', false, true, false)
      end
    end
  elseif isBoosting or isPurging then
    SetVehicleNitroBoostEnabled(vehicle, false)
    SetVehicleLightTrailEnabled(vehicle, false)
    SetVehicleNitroPurgeEnabled(vehicle, false)
    TriggerServerEvent('nitro:__sync', false, false, false)
  end

  return vehicle
end

Citizen.CreateThread(function ()
  local lastVehicle = 0

  while true do
    Citizen.Wait(0)
    lastVehicle = NitroLoop(lastVehicle)
  end
end)

RegisterNetEvent('nitro:__update')
AddEventHandler('nitro:__update', function (playerServerId, boostEnabled, purgeEnabled, lastVehicle)
  local playerId = GetPlayerFromServerId(playerServerId)

  -- Sometimes, the source player is disconnected from our session. If we don't
  -- check for that, their player ID will be -1. GetPlayerPed(-1) is our local
  -- player, so the logic to apply nitro sync will apply it to our vehicle when
  -- that happens.
  --
  -- Say, the source player enables nitro, but is not connected in our session.
  -- Nitro is then synced on the vehicle for player -1, which is us, so nitro is
  -- activated on our vehicle. However, because we're not actually pressing the
  -- nitro key, our client will update the nitro state accordingly, and turn it
  -- off. That then syncs to the original source player, who has the exact same
  -- network issue as we do. Nitro will be disabled on his vehicle, but he's
  -- still pressing the nitro key, so it's being enabled right after. Long story
  -- short, this causes an infinite sync loop between all clients as long as at
  -- least one player has nitro activated.
  --
  -- Therefor, simply check if the source player is connected to our session. If
  -- not, ignore the synced state and don't do anything.
  if not NetworkIsPlayerConnected(playerId) then
    return
  end

  local player = GetPlayerPed(playerId)
  local vehicle = GetVehiclePedIsIn(player, lastVehicle)
  local driver = GetPedInVehicleSeat(vehicle, -1)

  SetVehicleNitroBoostEnabled(vehicle, boostEnabled)
  SetVehicleLightTrailEnabled(vehicle, boostEnabled)
  SetVehicleNitroPurgeEnabled(vehicle, purgeEnabled)
end)