using System.Data;
using System.Diagnostics;
using System.Text;
using Chloe.Infrastructure.Interception;

namespace DB
{


    public class DbCommandInterceptor : IDbCommandInterceptor
    {

        public void ReaderExecuting(IDbCommand command, DbCommandInterceptionContext<IDataReader> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        public void ReaderExecuted(IDbCommand command, DbCommandInterceptionContext<IDataReader> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        public void NonQueryExecuting(IDbCommand command, DbCommandInterceptionContext<int> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        public void NonQueryExecuted(IDbCommand command, DbCommandInterceptionContext<int> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        public void ScalarExecuting(IDbCommand command, DbCommandInterceptionContext<object> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        public void ScalarExecuted(IDbCommand command, DbCommandInterceptionContext<object> interceptionContext)
        {
            ToDb(command, interceptionContext.Exception);
        }

        private void ToDb(IDbCommand command, Exception exception)
        {

#if DEBUG
            Trace.WriteLine(command.CommandText);
            Trace.WriteLine(AppendDbCommandInfo(command));
#endif
        }

        private string AppendDbCommandInfo(IDbCommand command)
        {
            var sb = new StringBuilder();

            foreach (IDbDataParameter param in command.Parameters)
            {
                if (param == null)
                    continue;

                object value;
                if (param.Value == null || param.Value == DBNull.Value)
                {
                    value = "NULL";
                }
                else
                {
                    value = param.Value;

                    if (param.DbType == DbType.String || param.DbType == DbType.AnsiString ||
                        param.DbType == DbType.DateTime)
                        value = "'" + value + "'";
                }

                sb.AppendFormat("{3} {0} {1} = {2};", Enum.GetName(typeof(DbType), param.DbType), param.ParameterName,
                    value, Enum.GetName(typeof(ParameterDirection), param.Direction));
                sb.AppendLine();
            }

            return sb.ToString();
        }
    }
}