// Copyright (c) 2004-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// 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 
// 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.Data;
using System.Data.Common;
using System.ComponentModel;
using System.Collections.Generic;

namespace MySql.Data.MySqlClient
{
	/// <include file='docs/MySqlDataAdapter.xml' path='docs/class/*'/>
#if !CF
	[System.Drawing.ToolboxBitmap( typeof(MySqlDataAdapter), "MySqlClient.resources.dataadapter.bmp")]
	[System.ComponentModel.DesignerCategory("Code")]
	[Designer("MySql.Data.MySqlClient.Design.MySqlDataAdapterDesigner,MySqlClient.Design")]
#endif
	public sealed class MySqlDataAdapter : DbDataAdapter, IDbDataAdapter, IDataAdapter, ICloneable
	{
		private bool loadingDefaults;
        private int updateBatchSize;
        List<IDbCommand> commandBatch;

		/// <summary>
		/// Occurs during Update before a command is executed against the data source. The attempt to update is made, so the event fires.
		/// </summary>
		public event MySqlRowUpdatingEventHandler RowUpdating;

		/// <summary>
		/// Occurs during Update after a command is executed against the data source. The attempt to update is made, so the event fires.
		/// </summary>
		public event MySqlRowUpdatedEventHandler RowUpdated;

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/Ctor/*'/>
		public MySqlDataAdapter()
		{
			loadingDefaults = true;
            updateBatchSize = 1;
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/Ctor1/*'/>
		public MySqlDataAdapter(MySqlCommand selectCommand) : this()
		{
			SelectCommand = selectCommand;
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/Ctor2/*'/>
		public MySqlDataAdapter(string selectCommandText, MySqlConnection connection) : this()
		{
			SelectCommand = new MySqlCommand(selectCommandText, connection);
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/Ctor3/*'/>
		public MySqlDataAdapter(string selectCommandText, string selectConnString) : this()
		{
			SelectCommand = new MySqlCommand(selectCommandText, 
				new MySqlConnection(selectConnString) );
		}

		#region Properties

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/DeleteCommand/*'/>
#if !CF
		[Description("Used during Update for deleted rows in Dataset.")]
#endif
		public new MySqlCommand DeleteCommand 
		{
			get { return (MySqlCommand)base.DeleteCommand; }
			set { base.DeleteCommand = value; }
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/InsertCommand/*'/>
#if !CF
		[Description("Used during Update for new rows in Dataset.")]
#endif
		public new MySqlCommand InsertCommand 
		{
			get { return (MySqlCommand)base.InsertCommand; }
			set { base.InsertCommand = value; }
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/SelectCommand/*'/>
#if !CF
		[Description("Used during Fill/FillSchema")]
		[Category("Fill")]
#endif
		public new MySqlCommand SelectCommand 
		{
			get { return (MySqlCommand)base.SelectCommand; }
            set { base.SelectCommand = value; }
		}

		/// <include file='docs/MySqlDataAdapter.xml' path='docs/UpdateCommand/*'/>
#if !CF
		[Description("Used during Update for modified rows in Dataset.")]
#endif
		public new MySqlCommand UpdateCommand 
		{
			get { return (MySqlCommand)base.UpdateCommand; }
			set { base.UpdateCommand = value; }
		}

		internal bool LoadDefaults 
		{
			get { return loadingDefaults; }
			set { loadingDefaults = value; }
		}

		#endregion

        /// <summary>
        /// Open connection if it was closed.
        /// Necessary to workaround "connection must be open and valid" error
        /// with batched updates.
        /// </summary>
        /// <param name="state">Row state</param>
        /// <param name="openedConnections"> list of opened connections 
        /// If connection is opened by this function, the list is updated
        /// </param>
        /// <returns>true if connection was opened</returns>
        private void OpenConnectionIfClosed(DataRowState state,
            List<MySqlConnection> openedConnections)
        {
            MySqlCommand cmd = null;
            switch (state)
            {
                case DataRowState.Added:
                    cmd = InsertCommand;
                    break;
                case DataRowState.Deleted:
                    cmd = DeleteCommand;
                    break;
                case DataRowState.Modified:
                    cmd = UpdateCommand;
                    break;
                default:
                    return;
            }

            if (cmd != null && cmd.Connection != null &&
                cmd.Connection.connectionState == ConnectionState.Closed)
            {
                cmd.Connection.Open();
                openedConnections.Add(cmd.Connection);
            }
        }


        protected override int Update(DataRow[] dataRows, DataTableMapping tableMapping)
        {

            List<MySqlConnection> connectionsOpened = new List<MySqlConnection>();

            try
            {
                // Open connections for insert/update/update commands, if 
                // connections are closed.
                foreach(DataRow row in dataRows)
                {
                    OpenConnectionIfClosed(row.RowState, connectionsOpened);
                }

                int ret = base.Update(dataRows, tableMapping);

                return ret;
            }
            finally 
            {
                foreach(MySqlConnection c in connectionsOpened)
                    c.Close();
            }
        }


        #region Batching Support

        public override int UpdateBatchSize
        {
            get { return updateBatchSize; }
            set { updateBatchSize = value; }
        }

        protected override void InitializeBatching()
        {
            commandBatch = new List<IDbCommand>();
        }

        protected override int AddToBatch(IDbCommand command)
        {
            // the first time each command is asked to be batched, we ask
            // that command to prepare its batchable command text.  We only want
            // to do this one time for each command
            MySqlCommand commandToBatch = (MySqlCommand)command;
            if (commandToBatch.BatchableCommandText == null)
                commandToBatch.GetCommandTextForBatching();

            IDbCommand cloneCommand = (IDbCommand)((ICloneable)command).Clone();
            commandBatch.Add(cloneCommand);

            return commandBatch.Count - 1;
        }

        protected override int ExecuteBatch()
        {
            int recordsAffected = 0;
            int index = 0;
            while (index < commandBatch.Count)
            {
                MySqlCommand cmd = (MySqlCommand)commandBatch[index++];
                for (int index2 = index; index2 < commandBatch.Count; index2++,index++)
                {
                    MySqlCommand cmd2 = (MySqlCommand)commandBatch[index2];
                    if (cmd2.BatchableCommandText == null || 
                        cmd2.CommandText != cmd.CommandText) break;
                    cmd.AddToBatch(cmd2);
                }
                recordsAffected += cmd.ExecuteNonQuery();
            }
            return recordsAffected;
        }

        protected override void ClearBatch()
        {
            if (commandBatch.Count > 0)
            {
                MySqlCommand cmd = (MySqlCommand)commandBatch[0];
                if (cmd.Batch != null)
                    cmd.Batch.Clear();
            }
            commandBatch.Clear();
        }

        protected override void TerminateBatching()
        {
            ClearBatch();
            commandBatch = null;
        }

        protected override IDataParameter GetBatchedParameter(int commandIdentifier, int parameterIndex)
        {
            return (IDataParameter)commandBatch[commandIdentifier].Parameters[parameterIndex];
        }

        #endregion

		/// <summary>
		/// Overridden. See <see cref="DbDataAdapter.CreateRowUpdatedEvent"/>.
		/// </summary>
		/// <param name="dataRow"></param>
		/// <param name="command"></param>
		/// <param name="statementType"></param>
		/// <param name="tableMapping"></param>
		/// <returns></returns>
		override protected RowUpdatedEventArgs CreateRowUpdatedEvent(DataRow dataRow, IDbCommand command, StatementType statementType, DataTableMapping tableMapping)
		{
			return new MySqlRowUpdatedEventArgs(dataRow, command, statementType, tableMapping);
		}

		/// <summary>
		/// Overridden. See <see cref="DbDataAdapter.CreateRowUpdatingEvent"/>.
		/// </summary>
		/// <param name="dataRow"></param>
		/// <param name="command"></param>
		/// <param name="statementType"></param>
		/// <param name="tableMapping"></param>
		/// <returns></returns>
		override protected RowUpdatingEventArgs CreateRowUpdatingEvent(DataRow dataRow, IDbCommand command, StatementType statementType, DataTableMapping tableMapping)
		{
			return new MySqlRowUpdatingEventArgs(dataRow, command, statementType, tableMapping);
		}

		/// <summary>
		/// Overridden. Raises the RowUpdating event.
		/// </summary>
		/// <param name="value">A MySqlRowUpdatingEventArgs that contains the event data.</param>
		override protected void OnRowUpdating(RowUpdatingEventArgs value)
		{
            if (RowUpdating != null)
                RowUpdating(this, (value as MySqlRowUpdatingEventArgs));
		}

		/// <summary>
		/// Overridden. Raises the RowUpdated event.
		/// </summary>
		/// <param name="value">A MySqlRowUpdatedEventArgs that contains the event data. </param>
		override protected void OnRowUpdated(RowUpdatedEventArgs value)
		{
            if (RowUpdated != null)
                RowUpdated(this, (value as MySqlRowUpdatedEventArgs));
		}
	}

	/// <summary>
	/// Represents the method that will handle the <see cref="MySqlDataAdapter.RowUpdating"/> event of a <see cref="MySqlDataAdapter"/>.
	/// </summary>
	public delegate void MySqlRowUpdatingEventHandler(object sender, MySqlRowUpdatingEventArgs e);

	/// <summary>
	/// Represents the method that will handle the <see cref="MySqlDataAdapter.RowUpdated"/> event of a <see cref="MySqlDataAdapter"/>.
	/// </summary>
	public delegate void MySqlRowUpdatedEventHandler(object sender, MySqlRowUpdatedEventArgs e);

	/// <summary>
	/// Provides data for the RowUpdating event. This class cannot be inherited.
	/// </summary>
	public sealed class MySqlRowUpdatingEventArgs : RowUpdatingEventArgs
	{
		/// <summary>
		/// Initializes a new instance of the MySqlRowUpdatingEventArgs class.
		/// </summary>
		/// <param name="row">The <see cref="DataRow"/> to 
        /// <see cref="DbDataAdapter.Update(DataSet)"/>.</param>
		/// <param name="command">The <see cref="IDbCommand"/> to execute during <see cref="DbDataAdapter.Update(DataSet)"/>.</param>
		/// <param name="statementType">One of the <see cref="StatementType"/> values that specifies the type of query executed.</param>
		/// <param name="tableMapping">The <see cref="DataTableMapping"/> sent through an <see cref="DbDataAdapter.Update(DataSet)"/>.</param>
		public MySqlRowUpdatingEventArgs(DataRow row, IDbCommand command, StatementType statementType, DataTableMapping tableMapping) 
			: base(row, command, statementType, tableMapping) 
		{
		}

		/// <summary>
		/// Gets or sets the MySqlCommand to execute when performing the Update.
		/// </summary>
		new public MySqlCommand Command
		{
			get  { return (MySqlCommand)base.Command; }
			set  { base.Command = value; }
		}
	}

	/// <summary>
	/// Provides data for the RowUpdated event. This class cannot be inherited.
	/// </summary>
	public sealed class MySqlRowUpdatedEventArgs : RowUpdatedEventArgs
	{
		/// <summary>
		/// Initializes a new instance of the MySqlRowUpdatedEventArgs class.
		/// </summary>
		/// <param name="row">The <see cref="DataRow"/> sent through an <see cref="DbDataAdapter.Update(DataSet)"/>.</param>
		/// <param name="command">The <see cref="IDbCommand"/> executed when <see cref="DbDataAdapter.Update(DataSet)"/> is called.</param>
		/// <param name="statementType">One of the <see cref="StatementType"/> values that specifies the type of query executed.</param>
		/// <param name="tableMapping">The <see cref="DataTableMapping"/> sent through an <see cref="DbDataAdapter.Update(DataSet)"/>.</param>
		public MySqlRowUpdatedEventArgs(DataRow row, IDbCommand command, StatementType statementType, DataTableMapping tableMapping)
			: base(row, command, statementType, tableMapping) 
		{
		}

		/// <summary>
		/// Gets or sets the MySqlCommand executed when Update is called.
		/// </summary>
		new public MySqlCommand Command
		{
			get  { return (MySqlCommand)base.Command; }
		}
	}
}