using System;
using System.Data;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Linq;

public class GenericRepository<T> : IRepository<T>, IDisposable where T : class
{
    public GenericRepository(IDbContext context)
    {
        if (context == null)
        {
            throw new ArgumentException("An instance of DbContext is " +
                                        "required to use this repository.", "context");
        }

        Context = context;
        DbSet = Context.Set<T>();
    }

    protected IDbSet<T> DbSet { get; set; }
    protected IDbContext Context { get; set; }

    public virtual void Dispose()
    {

    }

    public virtual IQueryable<T> GetAll()
    {
        return DbSet;
    }

    public virtual IQueryable<T> GetAll(string include)
    {
        return DbSet.Include(include);
    }

    public virtual T GetById(dynamic id)
    {
        return DbSet.Find(id);
    }

    public virtual void Add(T entity)
    {
        var entry = Context.Entry(entity);

        if (entry.State != EntityState.Detached)
        {
            entry.State = EntityState.Added;
        }
        else
        {
            DbSet.Add(entity);
        }

        Context.SaveChanges();
    }

    public virtual void Update(T entity)
    {
        DbEntityEntry<T> entry = Context.Entry(entity);
        entry.State = EntityState.Modified;
        Context.SaveChanges();
    }

    public virtual void Delete(T entity)
    {
        DbEntityEntry<T> entry = Context.Entry(entity);

        if (entry.State != EntityState.Deleted)
        {
            entry.State = EntityState.Deleted;
        }
        else
        {
            DbSet.Attach(entity);
            DbSet.Remove(entity);
        }

        Context.SaveChanges();
    }

    public virtual void Delete(dynamic id)
    {
        T entity = GetById(id);

        if (entity != null)
        {
            Delete(entity);
        }
    }
}