using System.Collections.Generic;
using GeometryTD.DataTable;
using UnityEngine;

namespace GeometryTD.CustomComponent
{
    internal sealed class EnemyLifecycleTracker
    {
        private readonly HashSet<int> _trackedEnemyEntityIds = new();
        private readonly Dictionary<int, DREnemy> _trackedEnemyConfigByEntityId = new();

        public int AliveEnemyCount { get; private set; }

        public void Reset()
        {
            _trackedEnemyEntityIds.Clear();
            _trackedEnemyConfigByEntityId.Clear();
            AliveEnemyCount = 0;
        }

        public void TrackEnemy(int entityId, DREnemy enemyConfig)
        {
            _trackedEnemyEntityIds.Add(entityId);
            _trackedEnemyConfigByEntityId[entityId] = enemyConfig;
        }

        public bool Contains(int entityId)
        {
            return _trackedEnemyEntityIds.Contains(entityId);
        }

        public void HandleShowSuccess(int entityId)
        {
            if (_trackedEnemyEntityIds.Contains(entityId))
            {
                AliveEnemyCount++;
            }
        }

        public void HandleShowFailure(int entityId)
        {
            _trackedEnemyEntityIds.Remove(entityId);
            _trackedEnemyConfigByEntityId.Remove(entityId);
        }

        public bool TryHandleHideComplete(int entityId, out DREnemy enemyConfig)
        {
            enemyConfig = null;
            if (!_trackedEnemyEntityIds.Remove(entityId))
            {
                _trackedEnemyConfigByEntityId.Remove(entityId);
                return false;
            }

            _trackedEnemyConfigByEntityId.TryGetValue(entityId, out enemyConfig);
            _trackedEnemyConfigByEntityId.Remove(entityId);
            AliveEnemyCount = Mathf.Max(0, AliveEnemyCount - 1);
            return true;
        }

        public void CopyTrackedEntityIdsTo(List<int> buffer)
        {
            if (buffer == null)
            {
                return;
            }

            buffer.Clear();
            foreach (int trackedEnemyEntityId in _trackedEnemyEntityIds)
            {
                buffer.Add(trackedEnemyEntityId);
            }
        }
    }
}