using DatabaseCore;
using DatabaseCore.Models.Department;
using DepartmentBusinessLogic.BindingModels;
using DepartmentBusinessLogic.Interfaces;
using DepartmentBusinessLogic.ViewModels;
using ModuleTools.BusinessLogics;
using ModuleTools.Enums;
using ModuleTools.Models;
using System;
using System.Linq;

namespace DepartmentDatabaseImplementation.Implementations
{
	/// <summary>
	/// Реализация IDisciplineBlockService
	/// </summary>
	public class DisciplineBlockService : IDisciplineBlockService
	{
		public OperationResultModel Create(DisciplineBlockSetBindingModel model)
		{
			using var context = DatabaseManager.GetContext;

			var exsistEntity = context.DisciplineBlocks.FirstOrDefault(x => x.Title == model.Title);
			if (exsistEntity == null)
			{
				var entity = Mapper.MapToClass<DisciplineBlockSetBindingModel, DisciplineBlock>(model, true);
				context.DisciplineBlocks.Add(entity);
				context.SaveChanges();
				return OperationResultModel.Success(Mapper.MapToClass<DisciplineBlock, DisciplineBlockViewModel>(entity, true));
			}
			else
			{
				if (exsistEntity.IsDeleted)
				{
					exsistEntity = Mapper.MapToClass(model, exsistEntity, true);
					exsistEntity.IsDeleted = false;
					context.SaveChanges();
					return OperationResultModel.Success(Mapper.MapToClass<DisciplineBlock, DisciplineBlockViewModel>(exsistEntity, true));
				}
				else
				{
					return OperationResultModel.Error("Error:", "Элемент уже существует", ResultServiceStatusCode.ExsistItem);
				}
			}
		}

		public OperationResultModel Delete(DisciplineBlockGetBindingModel model)
		{
			using var context = DatabaseManager.GetContext;
			using var transaction = context.Database.BeginTransaction();
			try
			{
				var entity = context.DisciplineBlocks.FirstOrDefault(x => x.Id == model.Id);
				if (entity == null)
				{
					return OperationResultModel.Error("Error:", "Элемент не найден", ResultServiceStatusCode.NotFound);
				}
				else if (entity.IsDeleted)
				{
					return OperationResultModel.Error("Error:", "Элемент был удален", ResultServiceStatusCode.WasDelete);
				}
				var disciplines = context.Disciplines.Where(x => x.DisciplineBlockId == model.Id);
				if (disciplines.Any())
				{
					return OperationResultModel.Error("Error:", "Есть дисциплины, относящиеся к этому блоку", ResultServiceStatusCode.ExsistItem);
				}
				entity.IsDeleted = true;
				entity.DateDelete = DateTime.Now;

				context.SaveChanges();

				transaction.Commit();
			}
			catch (Exception)
			{
				transaction.Rollback();
				throw;
			}

			return OperationResultModel.Success(true);
		}

		public OperationResultModel Read(DisciplineBlockGetBindingModel model)
		{
			int countPages = 0;
			using var context = DatabaseManager.GetContext;

			// для одной записи
			if (model.Id.HasValue)
			{
				var entity = context.DisciplineBlocks.FirstOrDefault(x => x.Id == model.Id.Value);
				if (entity == null)
				{
					return OperationResultModel.Error("Error:", "Элемент не найден", ResultServiceStatusCode.NotFound);
				}
				return OperationResultModel.Success(Mapper.MapToClass<DisciplineBlock, DisciplineBlockViewModel>(entity, model.HaveRight));
			}

			var query = context.DisciplineBlocks.Where(x => !x.IsDeleted).AsQueryable();

			query = query.OrderBy(x => x.DisciplineBlockOrder);

			if (model.PageNumber.HasValue && model.PageSize.HasValue)
			{
				countPages = (int)Math.Ceiling((double)query.Count() / model.PageSize.Value);
				query = query
							.Skip(model.PageSize.Value * model.PageNumber.Value)
							.Take(model.PageSize.Value);
			}

			var result = new DisciplineBlockListViewModel
			{
				MaxCount = countPages,
				List = query.Select(x => Mapper.MapToClass<DisciplineBlock, DisciplineBlockViewModel>(x, model.HaveRight)).ToList()
			};

			return OperationResultModel.Success(result);
		}

		public OperationResultModel Update(DisciplineBlockSetBindingModel model)
		{
			using var context = DatabaseManager.GetContext;

			var entity = context.DisciplineBlocks.FirstOrDefault(x => x.Id == model.Id);
			if (entity == null)
			{
				return OperationResultModel.Error("Error:", "Элемент не найден", ResultServiceStatusCode.NotFound);
			}
			else if (entity.IsDeleted)
			{
				return OperationResultModel.Error("Error:", "Элемент был удален", ResultServiceStatusCode.WasDelete);
			}
			entity = Mapper.MapToClass(model, entity, true);

			context.SaveChanges();

			return OperationResultModel.Success(Mapper.MapToClass<DisciplineBlock, DisciplineBlockViewModel>(entity, true));
		}
	}
}