using CC.Yi.Model;
using Microsoft.EntityFrameworkCore;
using System.Collections.Concurrent;
using System.Threading;


namespace CC.Yi.DAL
{
    public class DbContentFactory
    {
        private static  DataContext Webcontext;

        public  DbContentFactory(DataContext webContext)
        {
            Webcontext = webContext;
        }

        //public static void Initialize(DataContext webContext)
        //{
        //    Webcontext = webContext;
        //}
        public static DataContext GetCurrentDbContent()
        {
            ////return new DataModelContainer();
            ////一次请求共用一个上下文实例
            ////每一次http请求都会开启一个新的线程，保证在一个线程中,DbContext是唯一的
            ////CallContext：是线程内部唯一的数据槽（一块内存空间/容器）,相当于一个键值对数据容器，通过key获取value了,需要引入System.Runtime.Remoting.Messaging;命名空间
            //DbContext db = CallContext.GetData("DbContext") as DbContext;
            ////从 CallContext 中检索具有指定key“DbContext”的对象，并强转为DbContext
            //if (db == null)//线程在数据槽里面没有此上下文
            //{
            //    db = Webcontext;
            //    CallContext.SetData("DbContext", db);//放到数据槽中去,DbContext是key，db是value
            //}
            //return db;
            return Webcontext;
        }

        //private static class CallContext
        //{
        //    static ConcurrentDictionary<string, AsyncLocal<object>> state = new ConcurrentDictionary<string, AsyncLocal<object>>();

        //    public static void SetData(string name, object data) =>
        //        state.GetOrAdd(name, _ => new AsyncLocal<object>()).Value = data;

        //    public static object GetData(string name) =>
        //        state.TryGetValue(name, out AsyncLocal<object> data) ? data.Value : null;
        //}
    }
}