using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using UnityEngine;

namespace DDD
{
    public class InventoryManager : Singleton<InventoryManager>, IManager
    {
        private Dictionary<string, ItemData> _itemDataLookup;
        private Dictionary<string, InventoryItemData> _inventoryItemDatas;
        
        public void PreInit()
        {
            
        }

        public Task Init()
        {
            return Task.CompletedTask;
        }

        public void PostInit()
        {
            InitializeItemData();
        }

        private void InitializeItemData()
        {
            var itemDataSo = DataManager.Instance.ItemDataSo;
            
            Debug.Assert(itemDataSo != null, "itemDataSo != null");

            _itemDataLookup = itemDataSo.GetDataList()
                .Where(item => !string.IsNullOrEmpty(item.Id))
                .ToDictionary(item => item.Id, item => item);

            _inventoryItemDatas = new Dictionary<string, InventoryItemData>(itemDataSo.GetDataCount());
        }

        public bool AddItem(string id, int quantity = 1)
        {
            if (!_itemDataLookup.ContainsKey(id))
            {
                Debug.LogError($"[Inventory] 등록되지 않은 아이템 ID: {id}");
                return false;
            }

            if (_inventoryItemDatas.TryGetValue(id, out var itemData))
            {
                itemData.Quantity += quantity;
            }
            else
            {
                _inventoryItemDatas[id] = new InventoryItemData(id, quantity);
            }

            EventBus.Broadcast(new InventoryChangedEvent());
            return true;
        }

        public bool RemoveItem(string id, int quantity = 1)
        {
            if (!_inventoryItemDatas.TryGetValue(id, out var itemData))
            {
                Debug.LogError($"[Inventory] 등록되지 않은 아이템 ID: {id}");
                return false;
            }
            
            if (itemData.Quantity < quantity)
            {
                Debug.LogWarning($"[Inventory] 보유 수량보다 삭제하는 수량이 더 많습니다 " +
                                 $"{id}, 보유 수량 : {itemData.Quantity}, 삭제 수량 : {quantity}");
                return false;
            }
            
            itemData.Quantity -= quantity;

            if (itemData.Quantity <= 0)
            {
                _inventoryItemDatas.Remove(id);
            }
            
            EventBus.Broadcast(new InventoryChangedEvent());
            return true;
        }
        
        public IReadOnlyDictionary<string, InventoryItemData> InventoryItems => _inventoryItemDatas;
        public bool TryGetItemData(string id, out ItemData itemData) => _itemDataLookup.TryGetValue(id, out itemData);
        public int GetItemCount(string id) => _inventoryItemDatas.TryGetValue(id, out var itemData) ? itemData.Quantity : 0;
        public ItemData GetItemDataByIdOrNull(string id)
        {
            _itemDataLookup.TryGetValue(id, out var itemData);
            return itemData;
        }
    }
}