using Microsoft.Extensions.Logging;
using SchoolAgainStudyContracts.BindingModel;
using SchoolAgainStudyContracts.BusinessLogicContracts;
using SchoolAgainStudyContracts.SearchModel;
using SchoolAgainStudyContracts.StorageContracts;
using SchoolAgainStudyContracts.ViewModel;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SchoolAgainStudyBusinessLogic.BusinessLogic
{
    public class TaskLogic : ITaskLogic
    {
        private readonly ILogger _logger;
        private readonly ITaskStorage _taskStorage;
        public TaskLogic(ILogger<TaskLogic> logger, ITaskStorage taskStorage)
        {
            _logger = logger;
            _taskStorage = taskStorage;
        }
        public List<TaskViewModel>? ReadList(TaskSearchModel? model)
        {
            _logger.LogInformation("ReadList. Title:{Title}.Id:{ Id}", model?.Title, model?.Id);
            var list = model == null ? _taskStorage.GetFullList() : _taskStorage.GetFilteredList(model);
            if (list == null)
            {
                _logger.LogWarning("ReadList return null list");
                return null;
            }
            _logger.LogInformation("ReadList. Count:{Count}", list.Count);
            return list;
        }
        public TaskViewModel? ReadElement(TaskSearchModel model)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            _logger.LogInformation("ReadElement. Title:{Title}. Id:{ Id}", model.Title, model.Id);
            var element = _taskStorage.GetElement(model);
            if (element == null)
            {
                _logger.LogWarning("ReadElement element not found");
                return null;
            }
            _logger.LogInformation("ReadElement find. Id:{Id}", element.Id);
            return element;
        }
        public bool Create(TaskBindingModel model)
        {
            CheckModel(model);
            if (_taskStorage.Insert(model) == null)
            {
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }
        public bool Update(TaskBindingModel model)
        {
            CheckModel(model);
            if (_taskStorage.Update(model) == null)
            {
                _logger.LogWarning("Update operation failed");
                return false;
            }
            return true;
        }
        public bool Delete(TaskBindingModel model)
        {
            CheckModel(model, false);
            _logger.LogInformation("Delete. Id:{Id}", model.Id);
            if (_taskStorage.Delete(model) == null)
            {
                _logger.LogWarning("Delete operation failed");
                return false;
            }
            return true;
        }
        private void CheckModel(TaskBindingModel model, bool withParams =
       true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (string.IsNullOrEmpty(model.Title))
            {
                throw new ArgumentNullException("Не задано название", nameof(model.Title));
            }
            if (model.TeacherId <= 0)
            {
                throw new ArgumentNullException("Неверно задан идентификатор учителя", nameof(model.TeacherId));
            }
            
            _logger.LogInformation("Task. Titel:{Title}.TeacherId:{TeacherId}. Id: {Id}", model.Title, model.TeacherId, model.Id);
            var element = _taskStorage.GetElement(new TaskSearchModel
            {
                Title = model.Title,
                TeacherId = model.TeacherId
            });
            if (element != null && element.Id != model.Id)
            {
                throw new InvalidOperationException("Задание с таким названием уже есть");
            }
        }
    }
}