// called upon Trade with People
 private void UpdateSupplyOnTradeWithPeople()
 {
     foreach (Good.GoodType type in goodsToSupply.Keys)
     {
         // store number of icons in inventory being displayed
         int countInInventory = GovtInventory.GetGoodsOfType(type).Count + PeoplesInventory.GetGoodsOfType(type).Count;
         // calculate how much was there before
         float currentSupply = goodsToSupply [type];
         float max           = (type == Good.GoodType.Ideas) ? MaxIdeasSupply : MaxDrugsSupply;
         int   projectedNum  = ((currentSupply / max) < 0.3f) ? 0 : Mathf.FloorToInt((currentSupply - (max * 0.3f)) / 100);
         float diff          = 100.0f * (projectedNum - countInInventory);    // 100 is value of single icon
         goodsToSupply [type] += diff;
     }
 }
    // called upon DetermineState(), alters number of icons in government inventory based on city's supply of good
    private void UpdateInventory()
    {
        foreach (Good.GoodType type in goodsToSupply.Keys)
        {
            float currentSupply = goodsToSupply [type];
            float max           = (type == Good.GoodType.Ideas) ? MaxIdeasSupply : MaxDrugsSupply;
            int   projectedNum  = ((currentSupply / max) < 0.3f) ? 0 : Mathf.FloorToInt((currentSupply - (max * 0.3f)) / 100);
            // projectedNum should be between 0 and 10 for most goods and max of 5 for ideas
            List <int> govtInventoryGoods   = GovtInventory.GetGoodsOfType(type);
            List <int> peopleInventoryGoods = PeoplesInventory.GetGoodsOfType(type);
            if (projectedNum < govtInventoryGoods.Count + peopleInventoryGoods.Count)
            {
                // consumed
                int numToRemove = govtInventoryGoods.Count + peopleInventoryGoods.Count - projectedNum;
                // take from people first
                for (int i = peopleInventoryGoods.Count - 1; i > 0 && numToRemove > 0; i--)
                {
                    PeoplesInventory.RemoveGoodIfAny(i);
                    numToRemove--;
                }
                for (int i = govtInventoryGoods.Count - 1; i > 0 && numToRemove > 0; i--)
                {
                    GovtInventory.RemoveGoodIfAny(i);
                    numToRemove--;
                }
            }
            else if (projectedNum > govtInventoryGoods.Count + peopleInventoryGoods.Count)
            {
                // produced
                int numToAdd = projectedNum - govtInventoryGoods.Count - peopleInventoryGoods.Count;
                for (int i = 0; i < numToAdd; i++)
                {
                    switch (type)
                    {
                    case Good.GoodType.Food:
                        GovtInventory.AddGood(ServiceLocator.Instance.food);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.food);
                        break;

                    case Good.GoodType.Drugs:
                        GovtInventory.AddGood(ServiceLocator.Instance.drugs);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.drugs);
                        break;

                    case Good.GoodType.Exotics:
                        GovtInventory.AddGood(ServiceLocator.Instance.exotics);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.exotics);
                        break;

                    case Good.GoodType.Fuel:
                        GovtInventory.AddGood(ServiceLocator.Instance.fuel);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.fuel);
                        break;

                    case Good.GoodType.Ideas:
                        GovtInventory.AddGood(ServiceLocator.Instance.ideas);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.ideas);
                        break;

                    case Good.GoodType.Medicine:
                        GovtInventory.AddGood(ServiceLocator.Instance.medicine);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.medicine);
                        break;

                    case Good.GoodType.Textiles:
                        GovtInventory.AddGood(ServiceLocator.Instance.textiles);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.textiles);
                        break;

                    case Good.GoodType.Water:
                        GovtInventory.AddGood(ServiceLocator.Instance.water);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.water);
                        break;

                    case Good.GoodType.Weapons:
                        GovtInventory.AddGood(ServiceLocator.Instance.weapons);
                        if (i + 1 >= numToAdd)
                        {
                            break;
                        }
                        i++;
                        PeoplesInventory.AddGood(ServiceLocator.Instance.weapons);
                        break;

                    default:
                        break;
                    }
                }
            }
        }
    }