using System;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using SepCore.Definition;
using SepCore.Entity;
using SepCore.CustomUtility;
using UnityEngine;
using UnityGameFramework.Runtime;
using Random = UnityEngine.Random;

namespace SepCore.UI
{
    public class ShopUseCase : IUIUseCase
    {
        private readonly Player _player;
        private readonly int _currentLevel;
        private readonly Action _onShopFinish;

        private readonly IReadOnlyList<GoodsConfig> _allGoods;

        private readonly List<GoodsConfig> _validGoods = new();
        private readonly Dictionary<Rarity, List<GoodsConfig>> _goodsByRarity = new();

        private readonly List<ShopGoodsSelection> _selections = new();
        private int _refreshTime;

        public ShopUseCase(Player player, int currentLevel, Action onShopFinish)
        {
            _player = player;
            _currentLevel = currentLevel;
            _onShopFinish = onShopFinish;
            _allGoods = GameEntry.Luban.GetTable<GoodsConfig>();

            BuildGoodsRarityPools();
        }

        public ShopRawData CreateInitialModel()
        {
            _refreshTime = 0;

            return new ShopRawData
            {
                CurrentLevel = _currentLevel,
                RefreshPrice = _currentLevel,
                PlayerCoin = _player.Coin,
                GoodsItems = BuildRandomGoodsItems(GameEntry.Luban.Global.ShopGoodsCount),
                PropItems = _player.Props,
                PropMaxCount = GameEntry.Luban.Global.PropMaxCount,
                WeaponItems = _player.Weapons,
                WeaponMaxCount = _player.WeaponCapacity
            };
        }

        public ShopRefreshResult TryRefresh(int cost)
        {
            if (_player.Coin < cost)
            {
                return null;
            }

            _player.Coin -= cost;

            int refreshPrice = (_refreshTime + 1) * _currentLevel;
            _refreshTime++;

            return new ShopRefreshResult
            {
                GoodsItems = BuildRandomGoodsItems(GameEntry.Luban.Global.ShopGoodsCount),
                RefreshPrice = refreshPrice
            };
        }

        public async UniTask<ShopPurchaseResult> TryPurchaseAsync(int goodsIndex)
        {
            if (goodsIndex < 0 || goodsIndex >= _selections.Count)
            {
                Log.Error("ShopFormUseCase::TryPurchase: Invalid index");
                return null;
            }

            ShopGoodsSelection selection = _selections[goodsIndex];
            if (selection == null)
            {
                Log.Warning("ShopFormUseCase::TryPurchase: Item already purchased.");
                return null;
            }

            if (_player.Coin < selection.Price)
            {
                return null;
            }

            DisplayItemRawData displayItem = await ApplyGoodsPurchaseAsync(selection);
            if (displayItem == null)
            {
                return null;
            }

            _player.Coin -= selection.Price;
            _selections[goodsIndex] = null;

            return new ShopPurchaseResult
            {
                GoodsIndex = goodsIndex,
                DisplayItem = displayItem
            };
        }

        public void Continue()
        {
            _onShopFinish?.Invoke();
        }

        private List<GoodsItemRawData> BuildRandomGoodsItems(int count)
        {
            if (_allGoods.Count == 0)
            {
                Log.Error("ShopFormUseCase::BuildRandomGoodsItems(): _allGoods is empty");
                return null;
            }

            int finalCount = Mathf.Min(count, _allGoods.Count);
            List<GoodsItemRawData> goodsItems = new List<GoodsItemRawData>(finalCount);
            _selections.Clear();

            int currentLevel = _currentLevel;
            float priceRandomPercent = GameEntry.Luban.Global.ShopPriceRandomPercent / 1000f;

            for (int i = 0; i < finalCount; i++)
            {
                Rarity rarity = RollRarity(currentLevel);
                GoodsConfig goodsConfig = PickGoodsByRarity(rarity);
                if (goodsConfig == null)
                {
                    Log.Error("ShopFormUseCase::BuildRandomGoodsItems: No available goods for selection.");
                    break;
                }

                GoodsItemRawData goodsItem = new GoodsItemRawData();
                int price;

                if (goodsConfig.GoodsType == GoodsType.Prop)
                {
                    PropConfig propConfig = GameEntry.Luban.Get<PropConfig>(goodsConfig.PropId);
                    int basePrice = propConfig.Price;

                    price = CalculateRandomizedPrice(basePrice, priceRandomPercent);
                    goodsItem.ItemType = ItemType.Prop;
                    goodsItem.Rarity = propConfig.Rarity;
                    goodsItem.DataRow = propConfig;
                }
                else if (goodsConfig.GoodsType == GoodsType.Weapon)
                {
                    WeaponConfig weaponConfig = GameEntry.Luban.Get<WeaponConfig>((int)goodsConfig.WeaponType);
                    int basePrice = weaponConfig.Price;

                    price = CalculateRandomizedPrice(basePrice, priceRandomPercent);
                    goodsItem.ItemType = ItemType.Weapon;
                    goodsItem.Rarity = weaponConfig.Rarity;
                    goodsItem.DataRow = weaponConfig;
                }
                else
                {
                    Log.Warning(
                        $"ShopFormUseCase::BuildRandomGoodsItems: Unsupported goods type = {goodsConfig.GoodsType}");
                    continue;
                }

                goodsItem.Price = price;

                _selections.Add(new ShopGoodsSelection
                {
                    GoodsType = goodsConfig.GoodsType,
                    PropId = goodsConfig.PropId,
                    WeaponType = goodsConfig.WeaponType,
                    Price = price
                });

                goodsItems.Add(goodsItem);
            }

            return goodsItems;
        }

        private void BuildGoodsRarityPools()
        {
            _goodsByRarity.Clear();
            _validGoods.Clear();

            foreach (GoodsConfig goods in _allGoods)
            {
                if (!TryGetGoodsRarity(goods, out Rarity rarity))
                {
                    continue;
                }

                _validGoods.Add(goods);

                if (!_goodsByRarity.TryGetValue(rarity, out List<GoodsConfig> list))
                {
                    list = new List<GoodsConfig>();
                    _goodsByRarity.Add(rarity, list);
                }

                list.Add(goods);
            }
        }

        private GoodsConfig PickGoodsByRarity(Rarity rarity)
        {
            if (_goodsByRarity.TryGetValue(rarity, out List<GoodsConfig> list) && list.Count > 0)
            {
                return list[Random.Range(0, list.Count)];
            }

            if (_validGoods.Count > 0)
            {
                return _validGoods[Random.Range(0, _validGoods.Count)];
            }

            return null;
        }

        private bool TryGetGoodsRarity(GoodsConfig goods, out Rarity rarity)
        {
            rarity = Rarity.None;

            if (goods.GoodsType == GoodsType.Prop)
            {
                PropConfig propConfig = GameEntry.Luban.Get<PropConfig>(goods.PropId);
                rarity = propConfig.Rarity;
                return true;
            }

            if (goods.GoodsType == GoodsType.Weapon)
            {
                WeaponConfig weaponConfig = GameEntry.Luban.Get<WeaponConfig>((int)goods.WeaponType);
                rarity = weaponConfig.Rarity;
                return true;
            }

            Log.Error("ShopUseCase.TryGetGoodsRarity: Unsupported goods type '{0}'.", goods.GoodsType);
            return false;
        }

        private Rarity RollRarity(int level)
        {
            return RarityUtility.SelectRarityForLevel(level);
        }

        private static int CalculateRandomizedPrice(int basePrice, float priceRandomPercent)
        {
            float offsetPercent = Random.Range(-priceRandomPercent, priceRandomPercent);
            int finalPrice = Mathf.RoundToInt(basePrice * (1f + offsetPercent));
            return Mathf.Max(GameEntry.Luban.Global.ShopMinPrice, finalPrice);
        }

        private async UniTask<DisplayItemRawData> ApplyGoodsPurchaseAsync(ShopGoodsSelection goods)
        {
            if (goods.GoodsType == GoodsType.Prop)
            {
                PropConfig propConfig = GameEntry.Luban.Get<PropConfig>(goods.PropId);
                _player.AddProp(new PropItem(propConfig));
                return new DisplayItemRawData
                {
                    IconAssetName = propConfig.Sprite,
                    Rarity = propConfig.Rarity,
                    IsWeapon = false
                };
            }

            if (goods.GoodsType == GoodsType.Weapon)
            {
                if (_player.Weapons.Count >= _player.WeaponCapacity)
                {
                    Log.Warning("ShopFormUseCase::ApplyGoodsPurchase: Weapon capacity is full.");
                    return null;
                }

                WeaponConfig weaponConfig = GameEntry.Luban.Get<WeaponConfig>((int)goods.WeaponType);
                int id = GameEntry.Entity.NextId();
                var weaponData = EntityDataFactory.Create(id, weaponConfig, _player.Id, CampType.Player);

                WeaponBase weapon = await _player.AddWeaponAsync(weaponData);
                if (weapon == null)
                {
                    Log.Warning(
                        $"ShopFormUseCase::ApplyGoodsPurchase: Show weapon failed, weapon type id = {goods.WeaponType}");
                    return null;
                }

                return new DisplayItemRawData
                {
                    IconAssetName = weaponConfig.Sprite,
                    Rarity = weaponConfig.Rarity,
                    IsWeapon = true
                };
            }

            return null;
        }

        public bool TryRecycleWeapon(int argsIndex, int argsPrice)
        {
            var weapons = _player.Weapons;
            if (weapons.Count <= 1)
            {
                Log.Warning("ShopFormUseCase::TryRecycleWeapon: Can not recycle the last weapon.");
                return false;
            }

            var weapon = weapons[argsIndex];

            int recyclePrice = Mathf.Max(0, argsPrice);
            if (!_player.RemoveWeapon(weapon))
            {
                Log.Warning("ShopFormUseCase::TryRecycleWeapon: Remove weapon failed.");
                return false;
            }

            _player.Coin += recyclePrice;
            return true;
        }

        public int CalculateRecyclePrice(int basePrice)
        {
            return Mathf.FloorToInt(basePrice * (GameEntry.Luban.Global.WeaponRecycleRate / 1000f));
        }
    }
}