using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace Ether
{
    public class BackPackSystem : Singleton<BackPackSystem>
    {
        private int maxNum = 100;

        /// <summary>
        /// 背包格子
        /// </summary>
        private Dictionary<int, PropItemData> gridDic = new Dictionary<int, PropItemData>();

        private Dictionary<int, PropItemData> freeDic = new Dictionary<int, PropItemData>();

        public void Init()
        {

        }

        /// <summary>
        /// 放入背包
        /// </summary>
        public bool PutIn(int itemId, int num)
        {
            PropItemData propItemData = PropItemSystem.Inst.GeneratePropItem(itemId, num);
            return PutIn(propItemData);
        }

        /// <summary>
        /// 放入背包
        /// </summary>
        public bool PutIn(PropItemData propItemData)
        {
            //不占背包格的物品
            if (!propItemData.PropItemTable.Occupy)
            {
                if (freeDic.TryGetValue(propItemData.itemId, out PropItemData bagItem))
                {
                    bagItem.num += propItemData.num;
                    propItemData.PushPool();
                }
                else
                {
                    freeDic.Add(propItemData.itemId, propItemData);
                }

                return true;
            }


            //占用背包格的物品
            int firstEmptyIndex = -1;

            for (int i = 0; i < maxNum; i++)
            {
                if (!gridDic.ContainsKey(i))
                {
                    if (firstEmptyIndex == -1)
                    {
                        firstEmptyIndex = i;
                    }
                    continue;
                }

                PropItemData bagItem = gridDic[i];

                if (bagItem.itemId == propItemData.itemId)
                {
                    bagItem.num += propItemData.num;
                    propItemData.PushPool();
                    return true;
                }
            }

            if (firstEmptyIndex == -1)
            {
                Debug.LogError("背包已满！");
                return false;
            }

            gridDic.Add(firstEmptyIndex, propItemData);
            return true;

        }

        /// <summary>
        /// 取出道具
        /// </summary>
        public void TakeOut(int itemId, int num)
        {
            //不占背包格的物品
            if (freeDic.TryGetValue(itemId, out PropItemData freeBagItem))
            {
                freeBagItem.num -= num;

                if (freeBagItem.num <= 0)
                {
                    freeBagItem.PushPool();
                    freeDic.Remove(itemId);
                }
                return;
            }

            //占用背包格的物品
            int removeNum = num;
            for (int i = 0; i < maxNum; i++)
            {
                if (!gridDic.ContainsKey(i))
                {
                    continue;
                }

                PropItemData bagItem = gridDic[i];

                if (bagItem.itemId == itemId)
                {
                    if (bagItem.num < removeNum)
                    {
                        removeNum -= bagItem.num;
                        bagItem.num = 0;
                    }
                    else
                    {
                        bagItem.num -= removeNum;
                        removeNum = 0;
                    }

                    if (bagItem.num == 0)
                    {
                        bagItem.PushPool();
                        gridDic.Remove(i);
                    }

                    if (removeNum == 0)
                    {
                        return;
                    }
                }
            }
        }

        /// <summary>
        /// 获取对应位置的道具数据
        /// </summary>
        public PropItemData GetPropItemByGridIndex(int index)
        {
            if (gridDic.ContainsKey(index))
            {
                return gridDic[index];
            }

            return null;
        }

        /// <summary>
        /// 根据itemId获取对应的道具数量
        /// </summary>
        public int GetPropItemNumByItemId(int itemId)
        {
            //不占背包格的物品
            if (freeDic.TryGetValue(itemId, out PropItemData bagItem))
            {
                return bagItem.num;
            }

            //占用背包格的物品
            int haveNum = 0;

            foreach (var itemPair in gridDic)
            {
                if (itemPair.Value.itemId == itemId)
                {
                    haveNum += itemPair.Value.num;
                }
            }

            return haveNum;
        }
    }
}