using System;
using System.Collections.Generic;
using System.Linq;
using SepCore.Definition;
using SepCore.Entity;
using Random = UnityEngine.Random;
using UnityGameFramework.Runtime;
using SepCore.CustomUtility;
using UnityEngine;

namespace SepCore.UI
{
    public class LevelUpUseCase : IUIUseCase
    {
        private readonly Action _onCompleted;
        private readonly LevelUpRewardConfig[] _allRewards;
        private readonly Dictionary<Rarity, List<LevelUpRewardConfig>> _rewardsByRarity = new();
        private readonly List<LevelUpRewardConfig> _validRewards = new();

        private int _refreshCount;
        private LevelUpRawData _currentModel;

        private readonly Player _player;

        public LevelUpUseCase(Player player, Action onCompleted)
        {
            _player = player;
            _onCompleted = onCompleted;
            _allRewards = GameEntry.Luban.GetTable<LevelUpRewardConfig>().ToArray();

            BuildRewardRarityPools();
        }

        public LevelUpRawData CreateInitialModel()
        {
            _refreshCount = 0;

            if (_player.PendingLevelPoints <= 0)
            {
                _currentModel = null;
                return null;
            }

            _currentModel = BuildModel(GameEntry.Luban.Global.LevelUpRefreshPriceBase);
            return _currentModel;
        }

        public LevelUpRawData TryRefresh(int refreshCost)
        {
            if (_currentModel == null)
            {
                return null;
            }

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

            _player.Coin -= refreshCost;

            _refreshCount++;
            _currentModel = BuildModel((_refreshCount + 1) * GameEntry.Luban.Global.LevelUpRefreshPriceBase);
            return _currentModel;
        }

        public LevelUpRawData SelectReward(int selectedIndex)
        {
            if (_currentModel?.Rewards == null)
            {
                return null;
            }

            if (selectedIndex < 0 || selectedIndex >= _currentModel.Rewards.Count)
            {
                Log.Error("LevelUpFormUseCase::SelectReward: Invalid index");
                return null;
            }

            ApplyReward(_currentModel.Rewards[selectedIndex]);

            if (--_player.PendingLevelPoints > 0)
            {
                _refreshCount = 0;
                _currentModel = BuildModel(GameEntry.Luban.Global.LevelUpRefreshPriceBase);
                return _currentModel;
            }

            _onCompleted?.Invoke();
            _currentModel = null;
            return null;
        }

        private LevelUpRawData BuildModel(int refreshPrice)
        {
            if (_allRewards.Length == 0)
            {
                Log.Error("LevelUpFormUseCase::BuildModel(): _allRewards is empty");
                return null;
            }

            int finalCount = Mathf.Min(GameEntry.Luban.Global.LevelUpRewardCount, _allRewards.Length);
            List<LevelUpRewardConfig> selections = new List<LevelUpRewardConfig>(finalCount);

            int currentLevel = _player.CurrentLevel;
            for (int i = 0; i < finalCount; i++)
            {
                Rarity rarity = RarityUtility.SelectRarityForLevel(currentLevel);
                LevelUpRewardConfig reward = PickRewardByRarity(rarity);
                if (reward == null)
                {
                    Log.Error("LevelUpFormUseCase::BuildModel(): No available reward for selection.");
                    break;
                }

                selections.Add(reward);
            }

            return new LevelUpRawData
            {
                Rewards = selections,
                RefreshPrice = refreshPrice
            };
        }

        private void ApplyReward(LevelUpRewardConfig reward)
        {
            _player.AddProp(new PropItem(reward.StatModifierConfigs, reward.Rarity, reward.Title, reward.Sprite));
        }

        private void BuildRewardRarityPools()
        {
            _rewardsByRarity.Clear();
            _validRewards.Clear();

            foreach (LevelUpRewardConfig reward in _allRewards)
            {
                Rarity rarity = reward.Rarity;
                _validRewards.Add(reward);

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

                list.Add(reward);
            }
        }

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

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

            return null;
        }
    }
}