// Copyright (c) 2009, 2021, Oracle and/or its affiliates.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
//
// This program is also distributed with certain software (including
// but not limited to OpenSSL) that is licensed under separate terms,
// as designated in a particular file or component or in included license
// documentation.  The authors of MySQL hereby grant you an
// additional permission to link the program and your derivative works
// with the separately licensed software that they have included with
// MySQL.
//
// Without limiting anything contained in the foregoing, this file,
// which is part of MySQL Connector/NET, is also subject to the
// Universal FOSS Exception, version 1.0, a copy of which can be found at
// http://oss.oracle.com/licenses/universal-foss-exception.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License, version 2.0, for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Threading;
using MySql.Data.Common;
using Sog.Properties;

namespace MySql.Data.MySqlClient
{
    internal class TracingDriver : Driver
    {
        private static long driverCounter;
        private long driverId;
        private ResultSet activeResult;
        private int rowSizeInBytes;

        public TracingDriver(MySqlConnectionStringBuilder settings)
          : base(settings)
        {
            this.driverId = Interlocked.Increment(ref driverCounter);
        }

        public override void Open()
        {
            base.Open();
            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.ConnectionOpened,
                Resources.TraceOpenConnection, this.driverId, this.Settings.ConnectionString, this.ThreadID);
        }

        public override void Close()
        {
            base.Close();
            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.ConnectionClosed,
                Resources.TraceCloseConnection, this.driverId);
        }

        public override void SendQuery(MySqlPacket p, int paramsPosition)
        {
            this.rowSizeInBytes = 0;
            string cmdText = this.Encoding.GetString(p.Buffer, paramsPosition, p.Length - paramsPosition);
            string normalizedQuery = null;

            if (cmdText.Length > 300)
            {
                QueryNormalizer normalizer = new QueryNormalizer();
                normalizedQuery = normalizer.Normalize(cmdText);
                cmdText = cmdText.Substring(0, 300);
            }

            base.SendQuery(p, paramsPosition);

            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.QueryOpened,
                Resources.TraceQueryOpened, this.driverId, this.ThreadID, cmdText);
            if (normalizedQuery != null)
            {
                MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.QueryNormalized,
            Resources.TraceQueryNormalized, this.driverId, this.ThreadID, normalizedQuery);
            }
        }

        protected override int GetResult(int statementId, ref int affectedRows, ref long insertedId)
        {
            try
            {
                int fieldCount = base.GetResult(statementId, ref affectedRows, ref insertedId);
                MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.ResultOpened,
                    Resources.TraceResult, this.driverId, fieldCount, affectedRows, insertedId);

                return fieldCount;
            }
            catch (MySqlException ex)
            {
                // we got an error so we report it
                MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.Error,
                    Resources.TraceOpenResultError, this.driverId, ex.Number, ex.Message);
                throw;
            }
        }

        public override ResultSet NextResult(int statementId, bool force)
        {
            // first let's see if we already have a resultset on this statementId
            if (this.activeResult != null)
            {
                // oldRS = activeResults[statementId];
                if (this.Settings.UseUsageAdvisor)
                {
                    this.ReportUsageAdvisorWarnings(statementId, this.activeResult);
                }

                MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.ResultClosed,
                    Resources.TraceResultClosed, this.driverId, this.activeResult.TotalRows, this.activeResult.SkippedRows,
                    this.rowSizeInBytes);
                this.rowSizeInBytes = 0;
                this.activeResult = null;
            }

            this.activeResult = base.NextResult(statementId, force);
            return this.activeResult;
        }

        public override int PrepareStatement(string sql, ref MySqlField[] parameters)
        {
            int statementId = base.PrepareStatement(sql, ref parameters);
            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.StatementPrepared,
                Resources.TraceStatementPrepared, this.driverId, sql, statementId);
            return statementId;
        }

        public override void CloseStatement(int id)
        {
            base.CloseStatement(id);
            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.StatementClosed,
                Resources.TraceStatementClosed, this.driverId, id);
        }

        public override void SetDatabase(string dbName)
        {
            base.SetDatabase(dbName);
            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.NonQuery,
                Resources.TraceSetDatabase, this.driverId, dbName);
        }

        public override void ExecuteStatement(MySqlPacket packetToExecute)
        {
            base.ExecuteStatement(packetToExecute);
            int pos = packetToExecute.Position;
            packetToExecute.Position = 1;
            int statementId = packetToExecute.ReadInteger(4);
            packetToExecute.Position = pos;

            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.StatementExecuted,
                Resources.TraceStatementExecuted, this.driverId, statementId, this.ThreadID);
        }

        public override bool FetchDataRow(int statementId, int columns)
        {
            try
            {
                bool b = base.FetchDataRow(statementId, columns);
                if (b)
                {
                    this.rowSizeInBytes += (this.handler as NativeDriver).Packet.Length;
                }

                return b;
            }
            catch (MySqlException ex)
            {
                MySqlTrace.TraceEvent(TraceEventType.Error, MySqlTraceEventType.Error,
                    Resources.TraceFetchError, this.driverId, ex.Number, ex.Message);
                throw;
            }
        }

        public override void CloseQuery(MySqlConnection connection, int statementId)
        {
            base.CloseQuery(connection, statementId);

            MySqlTrace.TraceEvent(TraceEventType.Information, MySqlTraceEventType.QueryClosed,
                Resources.TraceQueryDone, this.driverId);
        }

        public override List<MySqlError> ReportWarnings(MySqlConnection connection)
        {
            List<MySqlError> warnings = base.ReportWarnings(connection);
            foreach (MySqlError warning in warnings)
            {
                MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.Warning,
            Resources.TraceWarning, this.driverId, warning.Level, warning.Code, warning.Message);
            }

            return warnings;
        }

        private bool AllFieldsAccessed(ResultSet rs)
        {
            if (rs.Fields == null || rs.Fields.Length == 0)
            {
                return true;
            }

            for (int i = 0; i < rs.Fields.Length; i++)
            {
                if (!rs.FieldRead(i))
                {
                    return false;
                }
            }

            return true;
        }

        private void ReportUsageAdvisorWarnings(int statementId, ResultSet rs)
        {
            if (!this.Settings.UseUsageAdvisor)
            {
                return;
            }

            if (this.HasStatus(ServerStatusFlags.NoIndex))
            {
                MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
            Resources.TraceUAWarningNoIndex, this.driverId, UsageAdvisorWarningFlags.NoIndex);
            }
            else if (this.HasStatus(ServerStatusFlags.BadIndex))
            {
                MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
            Resources.TraceUAWarningBadIndex, this.driverId, UsageAdvisorWarningFlags.BadIndex);
            }

            // report abandoned rows
            if (rs.SkippedRows > 0)
            {
                MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
            Resources.TraceUAWarningSkippedRows, this.driverId, UsageAdvisorWarningFlags.SkippedRows, rs.SkippedRows);
            }

            // report not all fields accessed
            if (!this.AllFieldsAccessed(rs))
            {
                StringBuilder notAccessed = new StringBuilder("");
                string delimiter = "";
                for (int i = 0; i < rs.Size; i++)
                {
                    if (!rs.FieldRead(i))
                    {
                        notAccessed.AppendFormat("{0}{1}", delimiter, rs.Fields[i].ColumnName);
                        delimiter = ",";
                    }
                }

                MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
                    Resources.TraceUAWarningSkippedColumns, this.driverId, UsageAdvisorWarningFlags.SkippedColumns,
                    notAccessed.ToString());
            }

            // report type conversions if any
            if (rs.Fields != null)
            {
                foreach (MySqlField f in rs.Fields)
                {
                    StringBuilder s = new StringBuilder();
                    string delimiter = "";
                    foreach (Type t in f.TypeConversions)
                    {
                        s.AppendFormat("{0}{1}", delimiter, t.Name);
                        delimiter = ",";
                    }

                    if (s.Length > 0)
                    {
                        MySqlTrace.TraceEvent(TraceEventType.Warning, MySqlTraceEventType.UsageAdvisorWarning,
                Resources.TraceUAWarningFieldConversion, this.driverId, UsageAdvisorWarningFlags.FieldConversion,
                f.ColumnName, s.ToString());
                    }
                }
            }
        }
    }
}