using System.Collections.Generic;
using GeometryTD.CustomEvent;
using GeometryTD.CustomUtility;
using GeometryTD.DataTable;
using GeometryTD.Definition;
using UnityEngine;

namespace GeometryTD.CustomComponent
{
    public sealed class CombatRunResourceStore
    {
        private readonly List<TowerStatsData> _buildTowerStatsSnapshot = new();
        private readonly List<TowerItemData> _participantTowerSnapshot = new();
        private readonly BackpackInventoryData _rewardInventory = new();

        private BackpackInventoryData _combatInventorySnapshot = new();
        private bool _isCombatActive;

        public int CurrentCoin { get; private set; }
        public int CurrentGold => _isCombatActive ? GainedGold : 0;
        public int CurrentBaseHp { get; private set; }
        public int MaxBaseHp { get; private set; }
        public int CurrentBuildTowerCount => _isCombatActive ? _buildTowerStatsSnapshot.Count : 0;
        public int GainedCoin { get; private set; }
        public int GainedGold { get; private set; }

        public void InitializeForCombat(DRLevel level)
        {
            Reset();
            if (level == null)
            {
                return;
            }

            MaxBaseHp = Mathf.Max(0, level.BaseHp);
            CurrentBaseHp = MaxBaseHp;
            CurrentCoin = Mathf.Max(0, level.StartCoin);
            CacheCombatSnapshots();
            _isCombatActive = true;
        }

        public void MarkCombatEnded()
        {
            _isCombatActive = false;
        }

        public void Reset()
        {
            _isCombatActive = false;
            CurrentCoin = 0;
            CurrentBaseHp = 0;
            MaxBaseHp = 0;
            GainedCoin = 0;
            GainedGold = 0;
            _buildTowerStatsSnapshot.Clear();
            _participantTowerSnapshot.Clear();
            _combatInventorySnapshot = new BackpackInventoryData();
            _rewardInventory.Gold = 0;
            _rewardInventory.MuzzleComponents.Clear();
            _rewardInventory.BearingComponents.Clear();
            _rewardInventory.BaseComponents.Clear();
            _rewardInventory.Towers.Clear();
            _rewardInventory.ParticipantTowerInstanceIds.Clear();
        }

        public BackpackInventoryData GetRewardInventorySnapshot()
        {
            return InventoryCloneUtility.CloneInventory(_rewardInventory);
        }

        public BackpackInventoryData GetCombatInventorySnapshot()
        {
            return InventoryCloneUtility.CloneInventory(_combatInventorySnapshot);
        }

        public IReadOnlyList<TowerItemData> GetParticipantTowerSnapshot()
        {
            List<TowerItemData> snapshot = new List<TowerItemData>(_participantTowerSnapshot.Count);
            for (int i = 0; i < _participantTowerSnapshot.Count; i++)
            {
                TowerItemData tower = _participantTowerSnapshot[i];
                if (tower != null)
                {
                    snapshot.Add(InventoryCloneUtility.CloneTower(tower));
                }
            }

            return snapshot;
        }

        public IReadOnlyList<long> GetParticipantTowerInstanceIdSnapshot()
        {
            List<long> snapshot = new List<long>(_participantTowerSnapshot.Count);
            for (int i = 0; i < _participantTowerSnapshot.Count; i++)
            {
                TowerItemData tower = _participantTowerSnapshot[i];
                if (tower != null && tower.InstanceId > 0)
                {
                    snapshot.Add(tower.InstanceId);
                }
            }

            return snapshot;
        }

        public bool TryConsumeCoin(int coin)
        {
            int requiredCoin = Mathf.Max(0, coin);
            if (requiredCoin <= 0)
            {
                return true;
            }

            if (!_isCombatActive || CurrentCoin < requiredCoin)
            {
                return false;
            }

            CurrentCoin -= requiredCoin;
            FireCoinChangedEvent(-requiredCoin);
            return true;
        }

        public void AddCoin(int coin)
        {
            int gainedCoin = Mathf.Max(0, coin);
            if (!_isCombatActive || gainedCoin <= 0)
            {
                return;
            }

            CurrentCoin += gainedCoin;
            FireCoinChangedEvent(gainedCoin);
        }

        public int ApplyBaseDamage(int damage)
        {
            int resolvedDamage = Mathf.Max(0, damage);
            if (!_isCombatActive || resolvedDamage <= 0)
            {
                return CurrentBaseHp;
            }

            int previousBaseHp = CurrentBaseHp;
            CurrentBaseHp = Mathf.Max(0, CurrentBaseHp - resolvedDamage);
            int deltaBaseHp = CurrentBaseHp - previousBaseHp;
            if (deltaBaseHp != 0)
            {
                FireBaseHpChangedEvent(deltaBaseHp);
            }

            return CurrentBaseHp;
        }

        public bool TryGetBuildTowerStats(int buildIndex, out TowerStatsData stats)
        {
            stats = null;
            if (!_isCombatActive || buildIndex < 0 || buildIndex >= _buildTowerStatsSnapshot.Count)
            {
                return false;
            }

            TowerStatsData sourceStats = _buildTowerStatsSnapshot[buildIndex];
            if (sourceStats == null)
            {
                return false;
            }

            stats = InventoryCloneUtility.CloneTowerStats(sourceStats);
            return stats != null;
        }

        public void AddEnemyDefeatedReward(int gainedCoin, int gainedGold)
        {
            if (!_isCombatActive)
            {
                return;
            }

            int coin = Mathf.Max(0, gainedCoin);
            int gold = Mathf.Max(0, gainedGold);
            GainedCoin += coin;
            GainedGold += gold;
            if (coin > 0)
            {
                CurrentCoin += coin;
                FireCoinChangedEvent(coin);
            }

            if (gold > 0)
            {
                _rewardInventory.Gold += gold;
            }
        }

        public void AddSettlementGold(int gainedGold)
        {
            int gold = Mathf.Max(0, gainedGold);
            if (gold <= 0)
            {
                return;
            }

            GainedGold += gold;
            _rewardInventory.Gold += gold;
        }

        public void AddEnemyDefeatedLoot(TowerCompItemData droppedItem)
        {
            if (!_isCombatActive || droppedItem == null)
            {
                return;
            }

            AppendRewardItem(droppedItem);
        }

        private void CacheCombatSnapshots()
        {
            _buildTowerStatsSnapshot.Clear();
            _participantTowerSnapshot.Clear();
            _combatInventorySnapshot = GameEntry.PlayerInventory != null
                ? GameEntry.PlayerInventory.GetInventorySnapshot()
                : new BackpackInventoryData();
            if (GameEntry.PlayerInventory == null)
            {
                return;
            }

            IReadOnlyList<TowerItemData> towers = GameEntry.PlayerInventory.GetParticipantTowerSnapshot();
            if (towers == null || towers.Count <= 0)
            {
                return;
            }

            for (int i = 0; i < towers.Count; i++)
            {
                TowerItemData tower = towers[i];
                if (tower == null)
                {
                    continue;
                }

                _participantTowerSnapshot.Add(InventoryCloneUtility.CloneTower(tower));
                if (tower.Stats != null)
                {
                    _buildTowerStatsSnapshot.Add(InventoryCloneUtility.CloneTowerStats(tower.Stats));
                }
            }
        }

        private void FireCoinChangedEvent(int deltaCoin)
        {
            if (!_isCombatActive)
            {
                return;
            }

            GameEntry.Event.Fire(this, CombatCoinChangedEventArgs.Create(CurrentCoin, deltaCoin));
        }

        private void FireBaseHpChangedEvent(int deltaBaseHp)
        {
            if (!_isCombatActive)
            {
                return;
            }

            GameEntry.Event.Fire(this, CombatBaseHpChangedEventArgs.Create(CurrentBaseHp, deltaBaseHp));
        }

        private void AppendRewardItem(TowerCompItemData droppedItem)
        {
            switch (droppedItem)
            {
                case MuzzleCompItemData muzzleComp:
                    _rewardInventory.MuzzleComponents.Add(InventoryCloneUtility.CloneMuzzleComp(muzzleComp));
                    break;
                case BearingCompItemData bearingComp:
                    _rewardInventory.BearingComponents.Add(InventoryCloneUtility.CloneBearingComp(bearingComp));
                    break;
                case BaseCompItemData baseComp:
                    _rewardInventory.BaseComponents.Add(InventoryCloneUtility.CloneBaseComp(baseComp));
                    break;
            }
        }
    }
}