using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using SepCore.DataTable;
using SepCore.Definition;
using SepCore.Entity;
using GameFramework.Event;
using SepCore.AsyncTask;
using SepCore.CustomUtility;
using UnityEngine;
using UnityGameFramework.Runtime;

namespace SepCore.EnemyManager
{
    public class EnemyManagerComponent : GameFrameworkComponent
    {
        private const string EnemyGroupName = "Enemy";

        private EntityComponent _entity;
        private EnemyRegistry _enemyRegistry;
        private EnemySpawnScheduler _spawnScheduler;

        public List<EntityBase> Enemies => _enemyRegistry?.Enemies;

        [SerializeField] private int _spawnEnemyMaxCount = 5000;
        [SerializeField] private int _spawnDistanceFromPlayer = 20;

        private int _currentSpawnEnemyId;
        private int _currentLevel;
        private float _duration;
        private float _baseDuration;

        private Transform _player;
        private ISpawnPositionStrategy _spawnPositionStrategy;

        public float SpawnRateScale => _spawnScheduler?.SpawnRateScale ?? 1f;
        public float BattleDuration => _duration;
        public float ElapsedBattleTime => _spawnScheduler?.ElapsedTime ?? 0f;
        public int CurrentEnemyCount => _enemyRegistry?.Count ?? 0;

        #region Lifecycle

        private void Start()
        {
            _entity = GameEntry.Entity;
            _enemyRegistry = new EnemyRegistry();
            _spawnScheduler = new EnemySpawnScheduler();

            GameEntry.Event.Subscribe(HideEntityCompleteEventArgs.EventId, OnHideEntityComplete);
        }

        private void OnDestroy()
        {
            GameEntry.Event.Unsubscribe(HideEntityCompleteEventArgs.EventId, OnHideEntityComplete);

            _enemyRegistry = null;
            _spawnScheduler = null;
            _entity = null;
        }

        public void OnInit(DRLevel level, Player player)
        {
            _player = player != null ? player.CachedTransform : null;
            _spawnPositionStrategy = new RandomCircleSpawnStrategy(_spawnDistanceFromPlayer);

            _baseDuration = level.Duration;
            _duration = _baseDuration;

            _spawnScheduler.Init(level);
            _enemyRegistry.Clear();
            _currentSpawnEnemyId = 0;
        }

        public void OnUpdate(float elapseSeconds, float realElapseSeconds)
        {
            var spawnRequests = _spawnScheduler.Tick(elapseSeconds);
            foreach (var request in spawnRequests)
            {
                for (int j = 0; j < request.Count; j++)
                {
                    SpawnEnemyAsync(request.EnemyType).Forget();
                }
            }
        }

        public void OnReset()
        {
            _spawnScheduler.Reset();
            _enemyRegistry.Clear();
            _currentSpawnEnemyId = 0;
            _currentLevel = 0;
            _baseDuration = 0;
            _duration = 0;
        }

        #endregion

        private async UniTaskVoid SpawnEnemyAsync(EnemyType enemyType)
        {
            if (_player == null) return;

            if (_enemyRegistry.Count >= _spawnEnemyMaxCount) return;
            int entityPoolId = _currentSpawnEnemyId % _spawnEnemyMaxCount;
            var enemyData = EntityDataFactory.Create(entityPoolId, enemyType, _currentLevel);
            enemyData.Position = _spawnPositionStrategy.GetSpawnPosition(_player);
            _currentSpawnEnemyId++;

            EnemyBase enemy = await _entity.ShowEnemyAsync(enemyData);
            if (enemy == null)
            {
                return;
            }

            enemy.SetTarget(_player);
            _enemyRegistry.Register(enemy);
        }

        public void ClearEnemies()
        {
            foreach (var enemy in _enemyRegistry.Enemies)
            {
                if (enemy == null || !enemy.Available) continue;
                _entity.HideEntity(enemy);
            }

            _enemyRegistry.Clear();
        }

        public bool TryGetEnemy(int entityId, out EntityBase enemy)
        {
            return _enemyRegistry.TryGet(entityId, out enemy);
        }

        public void SetSpawnRateScale(float scale)
        {
            _spawnScheduler.SetSpawnRateScale(scale);
        }

        #region Event Handler

        private void OnHideEntityComplete(object sender, GameEventArgs e)
        {
            if (e is not HideEntityCompleteEventArgs ne) return;

            string entityGroupName = ne.EntityGroup.Name;
            if (entityGroupName == EnemyGroupName)
            {
                _enemyRegistry.Remove(ne.EntityId);
            }
        }

        #endregion
    }
}