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 "Остановка"
    /// </summary>
    public class StopLogic : IStopLogic
    {
        /// <summary>
        /// Логгер
        /// </summary>
        private readonly ILogger _logger;

        /// <summary>
        /// Хранилище
        /// </summary>
        private readonly IStopStorage _stopStorage;

        /// <summary>
        /// Конструктор
        /// </summary>
        /// <param name="logger"></param>
        /// <param name="stopStorage"></param>
        public StopLogic(ILogger<StopLogic> logger, IStopStorage stopStorage)
        {
            _logger = logger;
            _stopStorage = stopStorage;
        }

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

            var list = model == null ? _stopStorage.GetFullList() : _stopStorage.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<StopViewModel>? ReadList(int count)
        {
            _logger.LogInformation("ReadList. Count: {Count}", count);

            var list = _stopStorage.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 StopViewModel? ReadElement(StopSearchModel model)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }

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

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

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

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

            if (_stopStorage.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(StopBindingModel model)
        {
            CheckModel(model);
            _logger.LogInformation("Update. Stop.Id: {Id}", model.Id);

            if (_stopStorage.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(StopBindingModel model)
        {
            CheckModel(model, false);
            _logger.LogInformation("Delete. Stop.Id: {Id}", model.Id);

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

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

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

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

        /// <summary>
        /// Проверка модели
        /// </summary>
        /// <param name="model"></param>
        /// <param name="withParams"></param>
        private void CheckModel(StopBindingModel 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 остановки", nameof(model.Name));
            }
            if (string.IsNullOrEmpty(model.Street))
            {
                throw new ArgumentNullException("Не указано название улицы", nameof(model.Street));
            }
            if (model.Number <= 0)
            {
                throw new ArgumentNullException("Не указан номер дома", nameof(model.Number));
            }

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

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