///*************************************************************************/
///*
///* 文件名    ：GenerateSqlCmdBase.cs    
///*
///* 程序说明  : SQL命令生成器基类
///* 原创作者  ：孙中吕 
///* 
///* Copyright 2006-2021 C/S框架网 www.csframework.com
///*
///**************************************************************************/

using CSFrameworkV5.Core.Common;
using System;
using System.Collections;
using System.Data;
using System.Data.Common;
using System.Text;

namespace CSFrameworkV5.Core.CodeGenerator
{
    /// <summary>
    /// 当SQL命令生成器生成代码后触发的事件
    /// </summary>
    /// <param name="insertSQL">已生成插入记录的SQL</param>
    /// <param name="deleteSQL">已生成删除记录的SQL</param>
    /// <param name="updateSQL">已生成更新记录的SQL</param>
    public delegate void GeneratedSQLEventHandle(string insertSQL,
        string deleteSQL, string updateSQL);

    /// <summary>
    /// SQL命令生成器基类
    /// </summary>
    public class GenerateSqlCmdBase : IGenerateSqlCommand
    {
        protected ICommandFactory _Factory;

        public GenerateSqlCmdBase(ICommandFactory factory)
        {
            _Factory = factory;
        }

        //Insert SQL语句
        protected string _sqlInsert = string.Empty;

        //Update SQL语句
        protected string _sqlUpdate = string.Empty;

        //Delete SQL语句
        protected string _sqlDelete = string.Empty;

        //Insert SQL命令
        protected DbCommand _cmdInsert = null;

        //Update SQL命令
        protected DbCommand _cmdUpdate = null;

        //Delete SQL命令
        protected DbCommand _cmdDelete = null;

        /// <summary>
        /// 单号字段名
        /// </summary>
        protected string _DocNoFieldName = string.Empty;

        /// <summary>
        /// 主键字段名,复合主键用分号";"分开.
        /// </summary>
        protected string _PrimaryFieldName = string.Empty;

        /// <summary>
        /// 外键字段名,复合外键用分号";"分开.
        /// </summary>
        protected string _ForeignFieldName = string.Empty;

        /// <summary>
        /// 是否主表
        /// </summary>
        protected bool _IsSummary = true;

        /// <summary>
        /// 是否使用并发功能的表
        /// </summary>
        /// <returns></returns>
        public bool IsConcurrentTable()
        {
            return _ConcurrentAttribute != null;
        }

        protected ORM_ConcurrentAttribute _ConcurrentAttribute = null;

        /// <summary>
        /// 获取单号字段名
        /// </summary>
        /// <returns></returns>
        public string GetDocNoFieldName()
        {
            return _DocNoFieldName;
        }

        /// <summary>
        /// 获取主键字段名
        /// </summary>
        /// <returns></returns>
        public string GetPrimaryFieldName()
        {
            return _PrimaryFieldName;
        }

        /// <summary>
        /// 获取外键字段名
        /// </summary>
        /// <returns></returns>
        public string GetForeignFieldName()
        {
            return _ForeignFieldName;
        }

        /// <summary>
        /// 是否主表
        /// </summary>
        /// <returns></returns>
        public bool IsSummary()
        {
            return _IsSummary;
        }

        /// <summary>
        /// 生成插入记录的SQL命令
        /// </summary>
        /// <param name="tran">事务</param>
        /// <returns></returns>
        public DbCommand GetInsertCommand(DbTransaction tran)
        {
            _cmdInsert.CommandText = CodeSafeHelper.GetSafeSQL(_sqlInsert);
            _cmdInsert.Connection = tran.Connection;
            _cmdInsert.Transaction = tran;
            return _cmdInsert;
        }

        /// <summary>
        /// 生成更新记录的SQL命令
        /// </summary>
        /// <param name="tran"></param>
        /// <returns></returns>
        public DbCommand GetUpdateCommand(DbTransaction tran)
        {
            _cmdUpdate.CommandText = CodeSafeHelper.GetSafeSQL(_sqlUpdate);
            _cmdUpdate.Connection = tran.Connection;
            _cmdUpdate.Transaction = tran;
            return _cmdUpdate;
        }


        /// <summary>
        /// 生成删除记录的SQL命令
        /// </summary>
        /// <param name="tran"></param>
        /// <returns></returns>
        public DbCommand GetDeleteCommand(DbTransaction tran)
        {
            _cmdDelete.CommandText = CodeSafeHelper.GetSafeSQL(_sqlDelete);
            _cmdDelete.Connection = tran.Connection;
            _cmdDelete.Transaction = tran;
            return _cmdDelete;
        }

        #region 生成SQL语句

        /// <summary>
        /// 生成插入记录用SQL语句
        /// </summary>
        /// <param name="tableName">表名</param>
        /// <param name="keyName">主键</param>
        /// <param name="fields">字段列表</param>
        /// <returns></returns>
        public string GenerateInsertSql(string tableName, string keyName,
            IList fields)
        {
            try
            {
                var sb = new StringBuilder();
                sb.Append("INSERT INTO " + tableName + " ( ");
                foreach (ColumnProperty colProper in fields)
                    if (fields.IndexOf(colProper) < fields.Count - 1)
                        sb.Append(colProper.ColumnName + ",");
                    else
                        sb.Append(colProper.ColumnName);
                sb.Append(" ) VALUES ( ");
                foreach (ColumnProperty colProper in fields)
                    if (fields.IndexOf(colProper) < fields.Count - 1)
                        sb.Append(_Factory.ParamSymboName +
                                  colProper.ColumnName + ",");
                    else
                        sb.Append(
                            _Factory.ParamSymboName + colProper.ColumnName);
                sb.Append(" )");
                return sb.ToStringEx();
            }
            catch
            {
                return string.Empty;
            }
        }

        /// <summary>
        /// 生成更新记录用SQL语句
        /// </summary>
        /// <param name="tableName">表名</param>
        /// <param name="keyName">主键</param>
        /// <param name="fields">字段列表</param>
        /// <returns></returns>
        public string GenerateUpdateSql(string tableName, string keyName,
            IList fields)
        {
            //生成SQL格式(标准)：UPDATE TABLE_NAME SET F1=@F1 WHERE KEY=@KEY
            //生成SQL格式(控制并发)：UPDATE TABLE_NAME SET F1=@F1 WHERE KEY=@KEY AND TS=@TS
            //生成SQL格式(复合主键)：UPDATE TABLE_NAME SET F1=@F1 WHERE KEY1=@KEY1 AND KEY2=@KEY2
            try
            {
                var isConcurrent = false;
                var sb = new StringBuilder();
                sb.Append("UPDATE " + tableName + " SET ");
                foreach (ColumnProperty colProper in fields)
                {
                    //是否并发字段
                    isConcurrent = IsConcurrentTable() &&
                                   _ConcurrentAttribute.TimestampFieldName ==
                                   colProper.ColumnName;

                    //主键及并发字段不拼接SQL脚本
                    if (colProper.IsPrimaryKey || isConcurrent) continue;

                    if (fields.IndexOf(colProper) == fields.Count - 1) //最后一个参数
                        sb.Append(colProper.ColumnName + "=" +
                                  _Factory.ParamSymboName +
                                  colProper.ColumnName);
                    else
                        sb.Append(colProper.ColumnName + "=" +
                                  _Factory.ParamSymboName +
                                  colProper.ColumnName + ",");
                }

                //删除最后面多余的调号
                sb = new StringBuilder(sb.ToStringEx().TrimEnd(','));

                //添加Where条件：记录主键
                sb.Append(" WHERE 1=1 " + SplitKeyName(keyName)); //主键

                //添加并发字段的WHERE 条件
                if (IsConcurrentTable())
                    sb.Append(" AND  " + GetConncurrentKeyName()); //并发

                return sb.ToStringEx();
            }
            catch
            {
                return string.Empty;
            }
        }

        /// <summary>
        /// 生成删除记录用SQL语句
        /// </summary>
        /// <param name="tableName">表名</param>
        /// <param name="keyName">主键</param>
        /// <param name="field">字段列表</param>
        /// <returns></returns>
        public string GenerateDeleteSql(string tableName, string keyName)
        {
            try
            {
                var sb = new StringBuilder();
                sb.Append("DELETE FROM " + tableName + " WHERE 1=1 " +
                          SplitKeyName(keyName)); //复合主键处理
                return sb.ToStringEx();
            }
            catch
            {
                return string.Empty;
            }
        }

        #endregion

        /// <summary>
        /// 复合主键处理
        /// </summary>
        /// <param name="keyName">字段名，多个字段用分号分开</param>
        /// <returns></returns>
        protected virtual string SplitKeyName(string keyName)
        {
            var strBuilder = new StringBuilder();
            var arrayStr = keyName.Split(';');
            foreach (var tempKeyName in arrayStr)
            {
                if (tempKeyName == "") continue;
                strBuilder.Append(" AND " + tempKeyName + "=" +
                                  _Factory.ParamSymboName + tempKeyName);
            }

            return strBuilder.ToStringEx();
        }

        /// <summary>
        /// 取并发操作的字段名
        /// </summary>
        /// <returns></returns>
        protected virtual string GetConncurrentKeyName()
        {
            if (IsConcurrentTable())
                return _ConcurrentAttribute.TimestampFieldName + "=" +
                       _Factory.ParamSymboName +
                       _ConcurrentAttribute.TimestampFieldName;
            else
                return "";
        }
    }
}