using KanSan.Base.Interfaces;
using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace KanSan.Base
{
    public class BaseRepository<TEntity> : IRepository<TEntity> where TEntity : class
    {
        internal KanSanContext context;
        internal DbSet<TEntity> dbSet;

        public BaseRepository(KanSanContext context)
        {
            this.context = context;
            if (context == null) throw new ArgumentNullException("context");
            this.dbSet = context.Set<TEntity>();
        }
        public virtual void Delete(TEntity entityToDelete)
        {
            if (context.Entry(entityToDelete).State == EntityState.Detached)
                dbSet.Attach(entityToDelete);
            dbSet.Remove(entityToDelete);
        }

        public void Delete(object id)
        {
            TEntity entityToDelete = dbSet.Find(id);
            Delete(entityToDelete);
        }

        public IEnumerable<TEntity> Get(Expression<Func<TEntity, bool>> filter = null, Func<IQueryable<TEntity>, IOrderedQueryable<TEntity>> orderBy = null, string includeProperties = "")
        {
            IQueryable<TEntity> query = dbSet;

            if (filter != null)
            {
                query = query.Where(filter);
            }

            if (includeProperties != null)
            {
                foreach (var includeProperty in includeProperties.Split
                (new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries))
                {
                    query = query.Include(includeProperty);
                }
            }


            if (orderBy != null)
            {
                return orderBy(query).ToList();
            }
            else
            {
                return query.ToList();
            }
        }

        public TEntity GetByID(object id)
        {
            return dbSet.Find(id);
        }

        public virtual void Insert(TEntity entity)
        {
            dbSet.Add(entity);
        }

        public void Update(TEntity entityToUpdate)
        {
            dbSet.Attach(entityToUpdate);
            IDatabaseEntry x = (entityToUpdate as IDatabaseEntry);
            if(x == null)
                return;
            if(x.ID.Equals(0))
            {
                // Scheint ein neuer Eintrag zu sein
                context.Entry(entityToUpdate).State = EntityState.Added;
            }
            else
            {
                context.Entry(entityToUpdate).State = EntityState.Modified;
            }
            
        }
    }
}