using System;
using System.Threading.Tasks;
using BlueWest.Tools;
using BlueWest.WebApi.EF;

namespace BlueWest.WebApi.Interfaces
{
    /// <summary>
    /// Empty constructor
    /// </summary>
    
    public struct ExchangeEvent { }
    /// <summary>
    /// Interface for getting and storing exchange rates data
    /// </summary>
    /// 
    public sealed class ExchangeInterface : EventListener<ExchangeEvent>, IDisposable, IAsyncDisposable
    {
        private readonly EventManager _eventManager;
        private readonly CountryDbContext _countryDbContext;
        private readonly FinanceDbContext _financeDbContext;
        private readonly UserDbContext _userDbContext;

        #region Initialization
        
        /// <summary>
        /// Database Ef context constructor
        /// </summary>
        /// <param name="countryDbContext">Country context</param>
        /// <param name="financeDbContext">Finance context</param>
        /// <param name="userDbContext">User context</param>
        /// <param name="eventManager">Event manager injection</param>
        
        public ExchangeInterface(
            CountryDbContext countryDbContext,
            FinanceDbContext financeDbContext, 
            UserDbContext userDbContext,
            EventManager eventManager)
        {
            _countryDbContext = countryDbContext;
            _financeDbContext = financeDbContext;
            _userDbContext = userDbContext;
            _eventManager = eventManager;
            Init();
        }

        /// <summary>
        /// Database Ef context constructor
        /// </summary>
        public ExchangeInterface() { }

        private void Init()
        {
            _eventManager.EventStartListening<ExchangeEvent>(this);
            Console.WriteLine($"{nameof(ExchangeInterface)} Just started!");
        }
        
        #endregion

        /// <summary>
        /// On Exchange Event
        /// </summary>
        /// <param name="eventType"></param>
        public void OnEvent(ExchangeEvent eventType)
        {
            Console.WriteLine($"Service received exchange {nameof(ExchangeEvent)}");
        }

        /// <summary>
        /// Stop Listening for events on dispose
        /// </summary>
        public void Dispose()
        {
            _eventManager.EventStopListening<ExchangeEvent>(this);
        }

        /// <summary>
        /// Stop Listening for events on dispose async
        /// </summary>
        /// <returns></returns>
        public ValueTask DisposeAsync()
        {
            _eventManager.EventStopListening<ExchangeEvent>(this);
            return ValueTask.CompletedTask;

        }
    }
}