using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TinyPosEntity
{
    public class EntityController
    {
        public static string ConnectionString { get; set; }

        private static EntityController instance;

        private EntityController(string connectionString)
        {
            EntityContext.ConnectionString = connectionString;
        }

        public static EntityController GetInstance()
        {
            if (string.IsNullOrEmpty(ConnectionString))
                throw new Exception("ConnectionString 값이 필요합니다.");

            if (instance == null)
                instance = new EntityController(ConnectionString);

            return instance;
        }

        public void Initialize()
        {
            Database.SetInitializer<EntityContext>(new EntityInitializer());

            using (EntityContext context = new EntityContext())
            {
                context.Database.CreateIfNotExists();
            }


            AddProductType(GetDefaultProductTypes());
        }

        private List<ProductType> GetDefaultProductTypes()
        {
            List<ProductType> productTypeList = new List<ProductType>();
            productTypeList.Add(new ProductType() { Name = "담배" });
            productTypeList.Add(new ProductType() { Name = "주류" });
            productTypeList.Add(new ProductType() { Name = "음료" });
            productTypeList.Add(new ProductType() { Name = "과자" });
            productTypeList.Add(new ProductType() { Name = "식료품" });
            productTypeList.Add(new ProductType() { Name = "잡화" });
            productTypeList.Add(new ProductType() { Name = "기타" });

            return productTypeList;
        }

        public void AddProductType(ProductType type)
        {
            using (EntityContext context = new EntityContext())
            {
                context.ProductTypes.Add(type);
                context.SaveChanges();
            }
        }

        public void AddProductType(List<ProductType> types)
        {
            using (EntityContext context = new EntityContext())
            {
                foreach (ProductType type in types)
                {
                    context.ProductTypes.Add(type);
                }

                context.SaveChanges();
            }
        }

        //public void AddStudent(Student student)
        //{
        //    using (EntityContext context = new EntityContext())
        //    {
        //        context.Students.Add(student);
        //        context.SaveChanges();
        //    }
        //}

        //public List<Student> FindStudent(string name)
        //{
        //    List<Student> result = null;
        //    using (EntityContext context = new EntityContext())
        //    {
        //        var student = from s in context.Students
        //                          where s.StudentName.Equals(name)
        //                          select s;

        //        if (student.Count() > 0)
        //            result = student.ToList();
        //    }

        //    return result;
        //}

        //public void RemoveStudent(Student student)
        //{
        //    using (EntityContext context = new EntityContext())
        //    {
        //        context.Database.ExecuteSqlCommand("DELETE FROM dbo.Students WHERE StudentName = {0}", student.StudentName);
        //    }
        //}
    }
}