using System;
using System.Collections.Generic;
using GeometryTD.CustomUtility;
using GeometryTD.Definition;
using UnityGameFramework.Runtime;

namespace GeometryTD.UI
{
    public sealed class ShopFormUseCase : IUIUseCase
    {
        private const int GoodsCount = 4;

        private readonly List<GoodsItemRawData> _currentGoods = new List<GoodsItemRawData>(GoodsCount);

        public bool PrepareForOpen(int runSeed = 0, int sequenceIndex = -1)
        {
            if (GameEntry.InventoryGeneration == null)
            {
                Log.Warning("ShopFormUseCase.PrepareForOpen() inventory generation component is null.");
                return false;
            }

            _currentGoods.Clear();
            _currentGoods.AddRange(GameEntry.InventoryGeneration.BuildShopGoods(GoodsCount, runSeed, sequenceIndex));
            return _currentGoods.Count == GoodsCount;
        }

        public ShopFormRawData CreateInitialModel()
        {
            return new ShopFormRawData
            {
                PlayerGold = GameEntry.PlayerInventory != null ? GameEntry.PlayerInventory.Gold : 0,
                GoodsItems = new List<GoodsItemRawData>(_currentGoods)
            };
        }

        public bool TryPurchase(int goodsIndex, out ShopFormRawData updatedRawData)
        {
            updatedRawData = null;
            if (goodsIndex < 0 || goodsIndex >= _currentGoods.Count)
            {
                Log.Warning("ShopFormUseCase.TryPurchase() goods index is invalid: {0}", goodsIndex);
                return false;
            }

            if (GameEntry.PlayerInventory == null)
            {
                Log.Warning("ShopFormUseCase.TryPurchase() player inventory is null.");
                return false;
            }

            GoodsItemRawData goodsItem = _currentGoods[goodsIndex];
            if (goodsItem == null || goodsItem.SourceItem == null)
            {
                return false;
            }

            if (goodsItem.IsPurchased)
            {
                Log.Warning("ShopFormUseCase.TryPurchase() goods item {0} already purchased.", goodsIndex);
                return false;
            }

            if (!GameEntry.PlayerInventory.TryPurchaseComponent(goodsItem.SourceItem, goodsItem.Price))
            {
                Log.Warning("ShopFormUseCase.TryPurchase() failed. Purchase command was rejected for goods item {0}.", goodsIndex);
                return false;
            }

            goodsItem.IsPurchased = true;
            updatedRawData = CreateInitialModel();
            return true;
        }

    }
}