using UniversityContracts.BindingModels;
using UniversityContracts.SearchModels;
using UniversityContracts.StoragesContracts;
using UniversityContracts.ViewModels;
using UniversityDatabaseImplement.Models;
using Microsoft.EntityFrameworkCore;

namespace UniversityDatabaseImplement.Implements
{
    public class RequirementStorage : IRequirementStorage
    {
        private void CheckSearchModel(RequirementSearchModel model)
        {
            if (model == null)
                throw new ArgumentNullException("Передаваемая модель для поиска равна нулю", nameof(model));
            if (!model.Id.HasValue && !model.DirectorId.HasValue)
                throw new ArgumentException("Все передаваемые поля поисковой модели оказались пусты или равны null");
        }
        public RequirementViewModel? Delete(RequirementBindingModel model)
        {
            using var context = new UniversityDB();
            var element = context.Requirements.FirstOrDefault(x => x.Id == model.Id);
            if (element != null)
            {
                context.Requirements.Remove(element);
                context.SaveChanges();
                return element;
            }
            return null;
        }

        public RequirementViewModel? GetElement(RequirementSearchModel model)
        {
            CheckSearchModel(model);
            using var context = new UniversityDB();
            if (!model.Id.HasValue)
            {
                return null;
            }
            return context.Requirements
                .Include(requirement => requirement.Director)
                .Include(requirement => requirement.Disciplines).ThenInclude(requirementByDiscipline => requirementByDiscipline.Discipline)
                .FirstOrDefault(x => model.Id.HasValue && x.Id == model.Id);
        }

        public List<RequirementViewModel> GetFilteredList(RequirementSearchModel model)
        {
            CheckSearchModel(model);
            using var context = new UniversityDB();
            return context.Requirements
                .Include(requirement => requirement.Director)
                .Include(requirement => requirement.Disciplines).ThenInclude(requirementByDiscipline => requirementByDiscipline.Discipline)
                .Where(x => x.DirectorId == model.DirectorId)
                .Select(x => (RequirementViewModel)x)
                .ToList();
        }

        public List<RequirementViewModel> GetFullList()
        {
            using var context = new UniversityDB();
            return context.Requirements
                .Include(requirement => requirement.Director)
                .Include(requirement => requirement.Disciplines).ThenInclude(requirementByDiscipline => requirementByDiscipline.Discipline)
                .Select(x => (RequirementViewModel)x)
                .ToList();
        }

        public RequirementViewModel? Insert(RequirementBindingModel model)
        {
            var newRequirement = Requirement.Create(model);
            if (newRequirement == null)
            {
                return null;
            }
            using var context = new UniversityDB();
            // Согласно тз при создании требований не требуется связывать ее с дисциплиными, поэтому нет UpdateDisciplines
            context.Requirements.Add(newRequirement);
            context.SaveChanges();
            return newRequirement;
        }
        public RequirementViewModel? Update(RequirementBindingModel model)
        {
            using var context = new UniversityDB();
            var requirement = context.Requirements.FirstOrDefault(x => x.Id == model.Id);
            if (requirement == null)
            {
                return null;
            }
            requirement.Update(model);
            context.SaveChanges();
            requirement.UpdateDisciplines(context, model);
            context.SaveChanges();
            return requirement;
        }
    }
}