using System;
using System.Linq;
using System.Linq.Expressions;
using YLShipBuildLandMap.Entity;

namespace YLShipBuildLandMap.Services.Common
{
    public class BaseService<TEntity> where TEntity : class
    {
        protected YLShipBuildLandMapContext DbContext { get; set; }

        public BaseService(YLShipBuildLandMapContext dbContext)
        {
            DbContext = dbContext;
        }
        public virtual TEntity Get(object keyValue)
        {
            return this.DbContext.Find<TEntity>(new object[] { keyValue });
        }
        public virtual int Delete(Expression<Func<TEntity, bool>> predicate)
        {

            this.DbContext.Set<TEntity>().Where(predicate).DeleteFromQuery();
            return this.DbContext.SaveChanges();
        }
        public virtual int Update(object keyValue, Func<TEntity, TEntity> updateFunc)
        {
            var entity = this.Get(keyValue);
            if (entity == null)
            { 
                this.DbContext.Add<TEntity>(updateFunc(entity));
            }
            else
            {
                this.DbContext.Update<TEntity>(updateFunc(entity));
            };
            return this.DbContext.SaveChanges();
        }
        public virtual int UpdateFromQuery(Expression<Func<TEntity, bool>> predicate, Expression<Func<TEntity, TEntity>> updateFunc)
        {
            this.DbContext.Set<TEntity>().Where(predicate).UpdateFromQuery(updateFunc);
            return this.DbContext.SaveChanges();
        }
    }
}