#region

using System;
using System.Data;
using System.Data.Common;
using System.Text;
using CSFramework.DB;
using CSFrameworkV5.Core;

#endregion

namespace CSFrameworkV5.DataAccess
{
    /// <summary>
    ///     数据访问层基类定义
    /// </summary>
    public class dalBase
    {
        /// <summary>
        ///     当前正在更新的数据集，调用Update方法时系统变量赋值
        /// </summary>
        protected DataSet _CurrentDataSet4Update = null;

        /// <summary>
        ///     当前正在更新的数据表，调用Update方法时系统变量赋值
        /// </summary>
        protected DataTable _CurrentTable4Update = null;

        protected IDatabase _Database;

        /// <summary>
        ///     是否生成带参数的SQL脚本,用于开发环境的调试。true:在调用DAL.Update方法时生成SQL脚本。
        /// </summary>
        protected bool _GenerateLastRowSQLText = false;

        /// <summary>
        ///     最后一次提交数据时生成的SQL脚本,用于开发环境的调试
        /// </summary>
        protected string _LastRowSQLText = "";

        /// <summary>
        ///     当前登录的用户信息
        /// </summary>
        protected Loginer _Loginer;

        /// <summary>
        ///     生成流水号码的类型(有规则流水号或GUID)
        /// </summary>
        protected UpdateKeyMode _UpdateSummaryKeyMode = UpdateKeyMode.None;

        /// <summary>
        ///     设置为受保护的构造器，不允许外部实例化
        /// </summary>
        /// <param name="loginer">当前登录的用户</param>
        protected dalBase(Loginer loginer)
        {
            if (loginer != null)
            {
                _Loginer = loginer;

                //若登录信息包含帐套编号，实例化该帐套对应的数据库连接
                if (!string.IsNullOrEmpty(loginer.DBID))
                    _Database = DatabaseProvider.GetDatabase(loginer.DBID);
            }
        }

        /// <summary>
        ///     建立连接的数据库（预设为当前账套对应的数据库）
        /// </summary>
        public IDatabase Database
        {
            get => _Database;
            set => _Database = value;
        }

        /// <summary>
        ///     SQL命令生成器的对象工厂
        /// </summary>
        /// <returns></returns>
        protected ICommandFactory GeneratorFactory =>
            new SqlGeneratorFactory(_Database);

        /// <summary>
        ///     适配器提交记录时触发的事件
        /// </summary>
        public virtual void AdapterRowUpdatingEvent(object sender,
            RowUpdatingEventArgs arg)
        {
            //生成SQL脚本
            if (_GenerateLastRowSQLText)
                _LastRowSQLText = BuildSQLText(arg.Command.Parameters);

            //日期数据是DateTime.MinValue，需要转换为DBNull.Value
            FixDateTime(arg.Command.Parameters);
        }

        /// <summary>
        ///     生成带参数的SQL脚本
        /// </summary>
        /// <param name="parameters">DbCommand参数</param>
        /// <returns></returns>
        private string BuildSQLText(IDataParameterCollection parameters)
        {
            var sb = new StringBuilder();
            foreach (DbParameter p in parameters)
                sb.AppendLine(p.ParameterName + "=" +
                              (p.Value == null || p.Value == DBNull.Value ||
                               p.Value.ToStringEx() == ""
                                  ? "null"
                                  : p.Value.ToStringEx()) + ", ");

            return sb.ToStringEx();
        }

        /// <summary>
        ///     将字段值为DateTime.MinValue转换为DBNULL
        /// </summary>
        /// <param name="parameters"></param>
        private void FixDateTime(IDataParameterCollection parameters)
        {
            foreach (DbParameter p in parameters)
            {
                if (p.DbType != DbType.DateTime ||
                    p.DbType != DbType.DateTime2 ||
                    p.DbType != DbType.Time) continue;

                if (p.Value == DBNull.Value || p.Value == null) continue;

                //日期数据是DateTime.MinValue，需要转换为DBNull.Value;                
                if (DateTime.Parse(p.Value.ToStringEx()).ToString("yyyyMMdd") ==
                    DateTime.MinValue.ToString("yyyyMMdd"))
                    p.Value = DBNull.Value;
            }
        }

        #region 事务控制

        /// <summary>
        ///     true表示手工启用事务控制，预设为false,表示平台自动启动是事务。
        /// </summary>
        protected bool _UserManualControlTrans = false;

        /// <summary>
        ///     当前事务
        /// </summary>
        protected DbTransaction _CurrentTrans;

        /// <summary>
        ///     当前事务的数据库连接
        /// </summary>
        protected DbConnection _CurrentConnection;

        /// <summary>
        ///     启用事务控制
        /// </summary>
        protected virtual void BeginTransaction()
        {
            _CurrentConnection = _Database.CreateConnection();
            _CurrentTrans = _CurrentConnection.BeginTransaction();
        }

        /// <summary>
        ///     提交事务
        /// </summary>
        protected virtual void CommitTransaction()
        {
            try
            {
                if (_CurrentTrans != null)
                {
                    _CurrentTrans.Commit();
                    _CurrentTrans = null;
                    _Database.Close(_CurrentConnection);
                }
            }
            catch
            {
                _Database.Close(_CurrentConnection);
                throw;
            }
        }

        /// <summary>
        ///     回滚事务
        /// </summary>
        protected virtual void RollbackTransaction()
        {
            try
            {
                if (_CurrentTrans != null)
                {
                    _CurrentTrans.Rollback();
                    _CurrentTrans = null;
                    _Database.Close(_CurrentConnection);
                }
            }
            catch
            {
                _Database.Close(_CurrentConnection);
                throw;
            }
        }

        #endregion
    }
}