using Microsoft.Extensions.Logging;
using RouteGuideContracts.BindingModels;
using RouteGuideContracts.BusinessLogicsContracts;
using RouteGuideContracts.SearchModels;
using RouteGuideContracts.StoragesContracts;
using RouteGuideContracts.ViewModels;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace RouteGuideBusinessLogics.BusinessLogics
{
    /// <summary>
    /// Бизнес-логика для сущности "Маршрут"
    /// </summary>
    public class RouteLogic : IRouteLogic
    {
        /// <summary>
        /// Логгер
        /// </summary>
        private readonly ILogger _logger;

        /// <summary>
        /// Хранилище
        /// </summary>
        private readonly IRouteStorage _routeStorage;

        /// <summary>
        /// Конструктор
        /// </summary>
        /// <param name="logger"></param>
        /// <param name="routeStorage"></param>
        public RouteLogic(ILogger<RouteLogic> logger, IRouteStorage routeStorage)
        {
            _logger = logger;
            _routeStorage = routeStorage;
        }

        /// <summary>
        /// Получение списка
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public List<RouteViewModel>? ReadList(RouteSearchModel? model)
        {
            _logger.LogInformation("ReadList. Route: {Name}.{Id}", model?.Id, model?.Name);

            var list = model == null ? _routeStorage.GetFullList() : _routeStorage.GetFilteredList(model);
            if (list == null)
            {
                _logger.LogWarning("ReadList. Returned null list");
                return null;
            }

            _logger.LogInformation("ReadList. Count: {Count}", list.Count);
            return list;
        }

        /// <summary>
        /// Получение списка из заданного количества элементов
        /// </summary>
        /// <param name="count"></param>
        /// <returns></returns>
        public List<RouteViewModel>? ReadList(int count)
        {
            _logger.LogInformation("ReadList. Count: {Count}", count);

            var list = _routeStorage.GetList(count);
            if (list == null)
            {
                _logger.LogWarning("ReadList. Returned null list");
                return null;
            }

            _logger.LogInformation("ReadList. Count: {Count}", list.Count);
            return list;
        }

        /// <summary>
        /// Получение отдельной записи
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public RouteViewModel? ReadElement(RouteSearchModel model)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }

            _logger.LogInformation("ReadElement. Route: {Name}.{Id}", model?.Id, model?.Name);

            var element = _routeStorage.GetElement(model!);
            if (element == null)
            {
                _logger.LogWarning("ReadElement. Element not found");
                return null;
            }

            _logger.LogInformation("ReadElement. Find Route.Id: {Id}", element.Id);
            return element;
        }

        /// <summary>
        /// Создание записи
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public bool Create(RouteBindingModel model)
        {
            CheckModel(model);
            _logger.LogInformation("Create. Route.Id: {Id}", model.Id);

            if (_routeStorage.Insert(model) == null)
            {
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }

        /// <summary>
        /// Изменение записи
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public bool Update(RouteBindingModel model)
        {
            CheckModel(model);
            _logger.LogInformation("Update. Route.Id: {Id}", model.Id);

            if (_routeStorage.Update(model) == null)
            {
                _logger.LogWarning("Update operation failed");
                return false;
            }
            return true;
        }

        /// <summary>
        /// Удаление записи
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        public bool Delete(RouteBindingModel model)
        {
            CheckModel(model, false);
            _logger.LogInformation("Delete. Route.Id: {Id}", model.Id);

            if (_routeStorage.Delete(model) == null)
            {
                _logger.LogWarning("Delete operation failed");
                return false;
            }
            return true;
        }

        /// <summary>
        /// Удаление записи
        /// </summary>
        /// <returns></returns>
        public bool Delete()
        {
            _logger.LogInformation("Delete. Route");

            if (_routeStorage.Delete() == null)
            {
                _logger.LogWarning("Delete operation failed");
                return false;
            }
            return true;
        }

        /// <summary>
        /// Удаление всех записей
        /// </summary>
        /// <returns></returns>
        public int Clear()
        {
            int count = _routeStorage.Clear();
            _logger.LogInformation("Clear. Delete {Count} Routes", count);
            return count;
        }

        /// <summary>
        /// Проверка модели
        /// </summary>
        /// <param name="model"></param>
        /// <param name="withParams"></param>
        private void CheckModel(RouteBindingModel model, bool withParams = true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (string.IsNullOrEmpty(model.Name))
            {
                throw new ArgumentNullException("Не указано название маршрута", nameof(model.Name));
            }
            if (model.TransportId == null || (model.TransportId is int && (int)model.TransportId < 0))
            {
                throw new ArgumentNullException("Некорректный идентификатор транспортного средства", nameof(model.TransportId));
            }

            _logger.LogInformation("CheckModel. Route.Id: {Id}", model.Id);

            var element = _routeStorage.GetElement(new RouteSearchModel
            {
                Name = model.Name
            });
            if (element != null && !element.Id.Equals(model.Id))
            {
                throw new InvalidOperationException("Маршрут с таким названием уже существует");
            }
        }
    }
}