using System;
using System.Data;
using System.Data.Common;

namespace XCode.DataAccessLayer
{
    /// <summary>网络数据库</summary>
    class Network : DbBase
    {
        #region 属性
        /// <summary>返回数据库类型。</summary>
        public override DatabaseType Type
        {
            get { return DatabaseType.Network; }
        }

        /// <summary>工厂</summary>
        public override DbProviderFactory Factory
        {
            get { throw new NotSupportedException(); }
        }
        #endregion

        #region 方法
        /// <summary>创建数据库会话</summary>
        /// <returns></returns>
        protected override IDbSession OnCreateSession() { return new NetworkSession(this); }

        /// <summary>创建元数据对象</summary>
        /// <returns></returns>
        protected override IMetaData OnCreateMetaData() { return new NetworkMetaData(); }
        #endregion

        #region 网络操作
        private IDatabase _Server;
        /// <summary>服务端数据库对象，该对象不可以使用与会话相关的功能</summary>
        public IDatabase Server
        {
            get { return _Server; }
            private set { _Server = value; }
        }

        /// <summary>请求服务器，更新基本信息到本地</summary>
        void UpdateInfo()
        {

        }
        #endregion
    }

    /// <summary>网络数据库会话</summary>
    class NetworkSession : DbSession
    {
        #region 构造函数
        public NetworkSession(IDatabase db) : base(db) { }
        #endregion

        #region 重载
        ///// <summary>
        ///// 查询记录集
        ///// </summary>
        ///// <param name="sql"></param>
        ///// <returns></returns>
        //public override DataSet Query(string sql)
        //{
        //    return base.Query(sql);
        //}

        ///// <summary>
        ///// 带主键信息查询记录集
        ///// </summary>
        ///// <param name="sql"></param>
        ///// <returns></returns>
        //public override DataSet QueryWithKey(string sql)
        //{
        //    return base.QueryWithKey(sql);
        //}

        /// <summary>不支持</summary>
        /// <param name="cmd"></param>
        /// <returns></returns>
        public override DataSet Query(DbCommand cmd)
        {
            throw new NotSupportedException();
        }

        ///// <summary>
        ///// 执行SQL查询，返回总记录数
        ///// </summary>
        ///// <param name="sql">SQL语句</param>
        ///// <returns></returns>
        //protected override Int64 QueryCountInternal(string sql)
        //{
        //    return base.QueryCountInternal(sql);
        //}

        /// <summary>快速查询单表记录数，稍有偏差</summary>
        /// <param name="tableName"></param>
        /// <returns></returns>
        public override Int64 QueryCountFast(String tableName)
        {
            return base.QueryCountFast(tableName);
        }

        ///// <summary>
        ///// 执行SQL语句，返回受影响的行数
        ///// </summary>
        ///// <param name="sql">SQL语句</param>
        ///// <param name="type">命令类型，默认SQL文本</param>
        ///// <param name="ps">命令参数</param>
        ///// <returns></returns>
        //public override int Execute(string sql)
        //{
        //    return base.Execute(sql);
        //}

        /// <summary>执行DbCommand，返回受影响的行数</summary>
        /// <param name="cmd">DbCommand</param>
        /// <returns></returns>
        public override Int32 Execute(DbCommand cmd)
        {
            throw new NotSupportedException();
        }

        ///// <summary>
        ///// 执行插入语句并返回新增行的自动编号
        ///// </summary>
        ///// <param name="sql">SQL语句</param>
        ///// <returns>新增行的自动编号</returns>
        //public override long InsertAndGetIdentity(string sql)
        //{
        //    return base.InsertAndGetIdentity(sql);
        //}

        ///// <summary>不支持</summary>
        ///// <returns></returns>
        //public override DbCommand CreateCommand()
        //{
        //    throw new NotSupportedException();
        //}

        /// <summary>返回数据源的架构信息</summary>
        /// <param name="collectionName">指定要返回的架构的名称。</param>
        /// <param name="restrictionValues">为请求的架构指定一组限制值。</param>
        /// <returns></returns>
        public override DataTable GetSchema(String collectionName, String[] restrictionValues)
        {
            return base.GetSchema(collectionName, restrictionValues);
        }
        #endregion
    }

    /// <summary>网络数据库元数据</summary>
    class NetworkMetaData : DbMetaData
    {

    }

    /// <summary>网络数据库服务器，处理客户端发来的数据库请求</summary>
    class NetworkDbServer
    {

    }
}