using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using BlueWater.Npcs.Customers;
using BlueWater.Utility;
using Sirenix.OdinInspector;
using UnityEngine;
using Random = UnityEngine.Random;

namespace BlueWater.Tycoons
{
    public class CustomerManager : Singleton<CustomerManager>
    {
        [Title("손님 데이터")]
        [field: SerializeField, Required]
        public CustomerDataSo CustomerDataSo { get; private set; }
        
        [SerializeField, Required]
        private Customer _customerPrefab;
        
        [SerializeField, Required]
        private Transform _customerSpawnTransform;
        
        [Title("대기중인 손님 정보")]
        [SerializeField]
        private float _checkEmptySeatInterval = 0.5f;

        [field: SerializeField]
        public List<Customer> InstanceCustomers { get; private set; } = new();
        
        [ShowInInspector]
        private Queue<int> _waitingCustomers = new();

        private CustomerTableController _customerTableController;
        private Coroutine _findEmptySeatCoroutineInstance;

        private void Start()
        {
            _customerTableController = TycoonManager.Instance.CustomerTableController;

            EventManager.OnCreateCustomer += TryFindEmptySeat;
        }

        private void OnDestroy()
        {
            EventManager.OnCreateCustomer -= TryFindEmptySeat;
        }

        public Customer CreateCustomer()
        {
            var currentLevelData = TycoonManager.Instance.GetCurrentLevelData();
            var newCustomer = Instantiate(_customerPrefab, _customerSpawnTransform.position, Quaternion.identity);
            newCustomer.Initialize(currentLevelData);
            RegisterCustomer(newCustomer);

            return newCustomer;
        }

        public void TryFindEmptySeat()
        {
            // 1. 빈 자리를 체크한다. (빈 자리가 있다면 생성)
            // 2. 빈 자리가 없는 경우, Queue에 대기 손님을 넣고 빈 자리가 생길 때 생성
            // 3. 생성하는 순간에 레벨 data 참조
            
            // 이미 대기열에 사람들이 있는 경우, 새로운 손님도 바로 대기열에 넣는다.
            if (_waitingCustomers.Count > 0)
            {
                _waitingCustomers.Enqueue(1);
                return;
            }
            
            // 대기열에는 아무도 없는 경우
            var emptySeat = _customerTableController.FindEmptySeat();
            if (emptySeat == null)
            {
                // 내가 첫 대기열 손님이 된다.
                _waitingCustomers.Enqueue(1);
                Utils.StartUniqueCoroutine(this, ref _findEmptySeatCoroutineInstance, CheckEmptySeatCoroutine());
                return;
            }

            var newCustomer = CreateCustomer();
            newCustomer.SetTableSeat(emptySeat);
            emptySeat.ReserveSeat();
            newCustomer.AIMovement.Move(emptySeat.SeatTransform.position);
        }

        private IEnumerator CheckEmptySeatCoroutine()
        {
            var checkEmptySeatInterval = new WaitForSeconds(_checkEmptySeatInterval);
            while (_waitingCustomers.Count > 0)
            {
                var emptySeat = _customerTableController.FindEmptySeat();
                if (emptySeat != null)
                {
                    _waitingCustomers.Dequeue();
                    var customer = CreateCustomer();
                    customer.SetTableSeat(emptySeat);
                    emptySeat.ReserveSeat();
                    customer.AIMovement.Move(emptySeat.SeatTransform.position);
                    
                    continue;
                }
                
                yield return checkEmptySeatInterval;
            }

            _findEmptySeatCoroutineInstance = null;
        }
        
        public void RegisterCustomer(Customer customer)
        {
            Utils.RegisterList(InstanceCustomers, customer);
        }

        public void UnregisterCustomer(Customer customer)
        {
            Utils.UnregisterList(InstanceCustomers, customer);
        }

        public CustomerData GetRandomCustomerData()
        {
            var customerDataCount = CustomerDataSo.GetDataCount();
            if (customerDataCount == 0)
            {
                Debug.LogError($"{CustomerDataSo}의 값이 비어있습니다.");
                return null;
            }
            
            return CustomerDataSo.GetRandomValue();
        }

        public List<Customer> GetCurrentCustomers() => InstanceCustomers;
    }
}