using System;
using System.Configuration;
using UnityEngine;

/// <summary>
/// This is a concrete, empty model for the buy state of the shop for you to implement
/// </summary>
public class BuyModel : ShopModel
{
    private Inventory tradePartner;
    public BuyModel(float pPriceModifier, int pItemCount, int pMoney) : base(pPriceModifier, pItemCount, pMoney)
    {

    }

    // Rather than modifying the whole class, we just reuse the existing stuff but don't make it create any items.
    // This makes it less work to make proper functionality, without having to break any potential old functionality.
    // Additionally, saves us work having to rip out the inventory's own ability to generate items.
    // Edit: Nevermind, let's just allow setting the inventory in the constructor, for shared inventories between models!
    public BuyModel(ShopObject pShopInitials, Inventory inventory = null) : this(pShopInitials.PriceModifier, 0, 0)
    {
        if (inventory != null) this.inventory = inventory;      
    }

    //------------------------------------------------------------------------------------------------------------------------
    //                                                 ConfirmSelectedItem()
    //------------------------------------------------------------------------------------------------------------------------        
    //Currently it just removes the selected item from the shop's inventory, rewrite this function and don't forget the unit test.

    public override void ConfirmSelectedItem()
    {
        if (tradePartner == null)
        {
            Debug.Assert(false,"Could not make trade because the shop has no trade partner");
            throw new NoTradePartnerException();
        }

        // if (tradePartner.Money < GetSelectedItem().basePrice * priceModifier)
        // {
        //     var up = new NotEnoughMoneyException();
        //     throw up;   // If you find this, you can keep it!
        // }
        var item = GetSelectedItem();
        tradePartner.ChangeBalance((int) (-item.basePrice * priceModifier));
        OnRemove(item);    // If there's a view subscribed, this will probably remove the item from it
        inventory.RemoveItemByIndex(selectedItemIndex);    // Before removing the item from the model's actual inventory
        tradePartner.AddItem(item);
        SelectItemByIndex(selectedItemIndex >= inventory.GetItemCount() ? --selectedItemIndex : selectedItemIndex);
    }

    public override void SetTradePartner(Inventory tradePartner)
    {
        this.tradePartner = tradePartner;
    }
}

public class NoTradePartnerException : Exception
{
}

public class InsufficientMoneyException : Exception
{
}