using SchoolAgainStudyContracts.BindingModel;
using SchoolAgainStudyContracts.ViewModel;
using SchoolAgainStudyDataModels.Models;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SchoolAgainStudyDataBaseImplements.Models
{
    public class Product : IProduct
    {
        [Required]
        public string Title { get; set; } = string.Empty;
        [Required]
        public string Description { get; set; } = string.Empty;
        [Required]
        public DateTime DateCreate { get; set; } 
        public int StudentId { get; set; }
        private Dictionary<int, IInterest>? _ProductInterests = null;
        [NotMapped]
        public Dictionary<int, IInterest> ProductInterests
        {
            get
            {
                if (_ProductInterests == null)
                {
                    _ProductInterests = Interests
                            .ToDictionary(recPC => recPC.InterestId, recPC => (recPC.Interest as IInterest));
                }
                return _ProductInterests;
            }
        }

        public int Id { get; set; }
        [ForeignKey("ProductId")]
        public virtual List<ProductInterest> Interests { get; set; } = new();
        [ForeignKey("ProductId")]
        public virtual List<Lesson> Lessons { get; set; } = new();
        public static Product Create(SchoolDataBase context, ProductBindingModel model)
        {
            return new Product()
            {
                Id = model.Id,
                Title = model.Title,
                Description = model.Description,
                DateCreate = model.DateCreate,
                StudentId = model.StudentId,
                Interests = model.ProductInterests.Select(x => new ProductInterest
                {
                    Interest = context.Interests.First(y => y.Id == x.Key),
                }).ToList()
            };
        }

        public void Update(ProductBindingModel model)
        {
            Title = model.Title;
            Description = model.Description;
            DateCreate = model.DateCreate;
        }

        public ProductViewModel GetViewModel => new()
        {
            Id = Id,
            Title = Title,
            Description = Description,
            DateCreate = DateCreate,
            StudentId = StudentId,
            ProductInterests = ProductInterests
        };

        public void UpdateInterests(SchoolDataBase context, ProductBindingModel model)
        {
            var productInterests = context.ProductInterests.Where(rec => rec.ProductId == model.Id).ToList();
            if (productInterests != null && productInterests.Count > 0)
            {
                context.ProductInterests.RemoveRange(productInterests.Where(rec => !model.ProductInterests.ContainsKey(rec.InterestId)));
                context.SaveChanges();

                foreach (var updateInterest in productInterests)
                {
                    model.ProductInterests.Remove(updateInterest.InterestId);
                }
                context.SaveChanges();
            }
            var product = context.Products.First(x => x.Id == Id);
            foreach (var pc in model.ProductInterests)
            {
                context.ProductInterests.Add(new ProductInterest
                {
                    Product = product,
                    Interest = context.Interests.First(x => x.Id == pc.Key),
                });
                context.SaveChanges();
            }
            _ProductInterests = null;
        }
    }
}