using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using NHibernate;
using NHibernate.Linq;
using Taloyhtio.GeneralSSO.Server.CodeFiles.Entities;
using Taloyhtio.GeneralSSO.Server.CodeFiles.Infrastructure.DataAccess;

namespace Taloyhtio.GeneralSSO.Server.CodeFiles.Repositories.Impl
{
    public abstract class RepositoryBase<TEntity, TKey> : IRepository<TEntity, TKey> where TEntity : PersistentObject<TKey>
    {
        public virtual TEntity GetById(TKey id)
        {
            var session = GetSession();
            return session.Linq<TEntity>().FirstOrDefault(e => ((object)e.Id).Equals(id));
        }

        protected abstract ISession GetSession();

        public virtual void Save(TEntity entity)
        {
            this.GetSession().SaveOrUpdate(entity);
        }

        public virtual IEnumerable<TEntity> GetAll()
        {
            return this.getAll();
        }

        public IEnumerable<TEntity> GetAllOrderBy<TProperty>(Expression<Func<TEntity, TProperty>> selector)
        {
            return this.GetAllOrderBy(selector, true);
        }

        private IQueryable<TEntity> getAll()
        {
            var session = this.GetSession();
            var query = session.Linq<TEntity>().Select(entity => entity);
            return query;
        }

        public IEnumerable<TEntity> GetAllOrderBy<TProperty>(Expression<Func<TEntity, TProperty>> selector, bool asc)
        {
            var query = this.getAll();
            if (asc)
            {
                return query.OrderBy(selector);
            }
            return query.OrderByDescending(selector);
        }

        public virtual void Delete(TEntity entity)
        {
            this.GetSession().Delete(entity);
        }

        public bool Exist(TKey key)
        {
            return this.GetById(key) != null;
        }
    }

}