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

namespace BlueWater
{
    public class CustomerManager : MonoBehaviour
    {
        [Title("손님 데이터")]
        [SerializeField, Required]
        private Customer _customerPrefab;
        
        [SerializeField, Required]
        private Transform _customerSpawnTransform;
        
        [Title("대기중인 손님 정보")]
        [SerializeField]
        private float _checkEmptySeatInterval = 0.5f;

        [SerializeField]
        private List<Customer> _instanceCustomers = new();
        
        [ShowInInspector]
        private Queue<Customer> _waitingCustomers = new();

        private CustomerTableManager _customerTableManager;
        private Coroutine _findEmptySeatCoroutineInstance;

        private void Start()
        {
            _customerTableManager = RestaurantManager.Instance.CustomerTableManager;
        }

        public void InstantiateCustomer()
        {
            var newCustomer = Instantiate(_customerPrefab, _customerSpawnTransform.position, Quaternion.identity);
            newCustomer.Initialize();
            RegisterCustomer(newCustomer);
        }

        public void TryFindEmptySeat(Customer customer)
        {
            // 이미 대기열에 사람들이 있는 경우, 새로운 손님도 바로 대기열에 넣는다.
            if (_waitingCustomers.Count > 0)
            {
                _waitingCustomers.Enqueue(customer);
                return;
            }
            
            // 대기열에는 아무도 없는 경우
            var emptySeat = _customerTableManager.FindEmptySeat();
            if (emptySeat == null)
            {
                // 내가 첫 대기열 손님이 된다.
                _waitingCustomers.Enqueue(customer);
                Utils.StartUniqueCoroutine(this, ref _findEmptySeatCoroutineInstance, CheckEmptySeatCoroutine());
                return;
            }
            
            customer.SetTableSeat(emptySeat);
            emptySeat.ReserveSeat();
            customer.AIMovement.Move(emptySeat.SeatTransform.position);
        }

        private IEnumerator CheckEmptySeatCoroutine()
        {
            var checkEmptySeatInterval = new WaitForSeconds(_checkEmptySeatInterval);
            while (_waitingCustomers.Count > 0)
            {
                var emptySeat = _customerTableManager.FindEmptySeat();
                if (emptySeat != null)
                {
                    var customer = _waitingCustomers.Dequeue();
                    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);
        }
    }
}