context: // 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.Collections;
  using System.ComponentModel;
  using System.Collections.Generic;
  
  
  namespace MySql.Data.MySqlClient
  {
    /// <summary>
    /// Represents a collection of parameters relevant to a <see cref="MySqlCommand"/> as well as their respective mappings to columns in a <see cref="System.Data.DataSet"/>. This class cannot be inherited.
    /// </summary>
    /// <include file='docs/MySqlParameterCollection.xml' path='MyDocs/MyMembers[@name="Class"]/*'/>
    public sealed partial class MySqlParameterCollection
    {
      List<MySqlParameter> items = new List<MySqlParameter>();
      private Dictionary<string,int> indexHashCS;
      private Dictionary<string,int> indexHashCI;
      //turns to true if any parameter is unnamed
      internal bool containsUnnamedParameters;
  
      internal MySqlParameterCollection(MySqlCommand cmd)
      {
        indexHashCS = new Dictionary<string, int>();
        indexHashCI = new Dictionary<string,int>(StringComparer.CurrentCultureIgnoreCase);
        containsUnnamedParameters = false;
        Clear();
      }
  
      /// <summary>
      /// Gets the number of MySqlParameter objects in the collection.
      /// </summary>
      public override int Count
      {
        get { return items.Count; }
      }
  
      #region Public Methods
  
      /// <summary>
      /// Gets the <see cref="MySqlParameter"/> at the specified index.
      /// </summary>
      /// <overloads>Gets the <see cref="MySqlParameter"/> with a specified attribute.
      /// [C#] In C#, this property is the indexer for the <see cref="MySqlParameterCollection"/> class.
      /// </overloads>
      public new MySqlParameter this[int index]
      {
        get { return InternalGetParameter(index); }
        set { InternalSetParameter(index, value); }
      }
  
      /// <summary>
      /// Gets the <see cref="MySqlParameter"/> with the specified name.
      /// </summary>
      public new MySqlParameter this[string name]
      {
        get { return InternalGetParameter(name); }
        set { InternalSetParameter(name, value); }
      }
  
      /// <summary>
      /// Adds the specified <see cref="MySqlParameter"/> object to the <see cref="MySqlParameterCollection"/>.
      /// </summary>
      /// <param name="value">The <see cref="MySqlParameter"/> to add to the collection.</param>
      /// <returns>The newly added <see cref="MySqlParameter"/> object.</returns>
      public MySqlParameter Add(MySqlParameter value)
      {
        return InternalAdd(value, -1);
      }
  
      /// <summary>
      /// Adds a <see cref="MySqlParameter"/> to the <see cref="MySqlParameterCollection"/> given the specified parameter name and value.
      /// </summary>
      /// <param name="parameterName">The name of the parameter.</param>
      /// <param name="value">The <see cref="MySqlParameter.Value"/> of the <see cref="MySqlParameter"/> to add to the collection.</param>
      /// <returns>The newly added <see cref="MySqlParameter"/> object.</returns>
      [Obsolete("Add(String parameterName, Object value) has been deprecated.  Use AddWithValue(String parameterName, Object value)")]
      public MySqlParameter Add(string parameterName, object value)
      {
        return Add(new MySqlParameter(parameterName, value));
      }
  
      public MySqlParameter AddWithValue(string parameterName, object value)
      {
        return Add(new MySqlParameter(parameterName, value));
      }
  
      /// <summary>
      /// Adds a <see cref="MySqlParameter"/> to the <see cref="MySqlParameterCollection"/> given the parameter name and the data type.
      /// </summary>
      /// <param name="parameterName">The name of the parameter.</param>
      /// <param name="dbType">One of the <see cref="MySqlDbType"/> values. </param>
      /// <returns>The newly added <see cref="MySqlParameter"/> object.</returns>
      public MySqlParameter Add(string parameterName, MySqlDbType dbType)
      {
        return Add(new MySqlParameter(parameterName, dbType));
      }
  
      /// <summary>
      /// Adds a <see cref="MySqlParameter"/> to the <see cref="MySqlParameterCollection"/> with the parameter name, the data type, and the column length.
      /// </summary>
      /// <param name="parameterName">The name of the parameter.</param>
      /// <param name="dbType">One of the <see cref="MySqlDbType"/> values. </param>
      /// <param name="size">The length of the column.</param>
      /// <returns>The newly added <see cref="MySqlParameter"/> object.</returns>
      public MySqlParameter Add(string parameterName, MySqlDbType dbType, int size)
      {
        return Add(new MySqlParameter(parameterName, dbType, size));
      }
  
      #endregion
  
      /// <summary>
      /// Removes all items from the collection.
      /// </summary>
      public override void Clear()
      {
        foreach (MySqlParameter p in items)
          p.Collection = null;
        items.Clear();
        indexHashCS.Clear();
        indexHashCI.Clear();
      }
  
      void CheckIndex(int index)
      {
        if (index < 0 || index >= Count)
          throw new IndexOutOfRangeException("Parameter index is out of range.");
      }
  
      private MySqlParameter InternalGetParameter(int index)
      {
        CheckIndex(index);
        return items[index];
      }
  
      private MySqlParameter InternalGetParameter(string parameterName)
      {
        int index = IndexOf(parameterName);
        if (index < 0)
        {
          // check to see if the user has added the parameter without a
          // parameter marker.  If so, kindly tell them what they did.
          if (parameterName.StartsWith("@", StringComparison.Ordinal) ||
                      parameterName.StartsWith("?", StringComparison.Ordinal))
          {
            string newParameterName = parameterName.Substring(1);
            index = IndexOf(newParameterName);
            if (index != -1)
              return items[index];
          }
          throw new ArgumentException("Parameter '" + parameterName + "' not found in the collection.");
        }
        return items[index];
      }
  
      private void InternalSetParameter(string parameterName, MySqlParameter value)
      {
        int index = IndexOf(parameterName);
        if (index < 0)
          throw new ArgumentException("Parameter '" + parameterName + "' not found in the collection.");
        InternalSetParameter(index, value);
      }
  
      private void InternalSetParameter(int index, MySqlParameter value)
      {
        MySqlParameter newParameter = value as MySqlParameter;
        if (newParameter == null)
          throw new ArgumentException("Resources.NewValueShouldBeMySqlParameter");
  
        CheckIndex(index);
        MySqlParameter p = (MySqlParameter)items[index];
  
        // first we remove the old parameter from our hashes
        indexHashCS.Remove(p.ParameterName);
        indexHashCI.Remove(p.ParameterName);
  
        // then we add in the new parameter
        items[index] = newParameter;
        indexHashCS.Add(value.ParameterName, index);
        indexHashCI.Add(value.ParameterName, index);
      }
  
      /// <summary>
      /// Gets the location of the <see cref="MySqlParameter"/> in the collection with a specific parameter name.
      /// </summary>
      /// <param name="parameterName">The name of the <see cref="MySqlParameter"/> object to retrieve. </param>
      /// <returns>The zero-based location of the <see cref="MySqlParameter"/> in the collection.</returns>
      public override int IndexOf(string parameterName)
      {
        int i = -1;
        if (!indexHashCS.TryGetValue(parameterName, out i) &&
          !indexHashCI.TryGetValue(parameterName, out i))
          return -1;
        return i;
      }
  
      /// <summary>
      /// Gets the location of a <see cref="MySqlParameter"/> in the collection.
      /// </summary>
      /// <param name="value">The <see cref="MySqlParameter"/> object to locate. </param>
      /// <returns>The zero-based location of the <see cref="MySqlParameter"/> in the collection.</returns>
      /// <overloads>Gets the location of a <see cref="MySqlParameter"/> in the collection.</overloads>
      public override int IndexOf(object value)
      {
        MySqlParameter parameter = value as MySqlParameter;
        if (null == parameter)
          throw new ArgumentException("Argument must be of type DbParameter", "value");
        return items.IndexOf(parameter);
      }
  
      internal void ParameterNameChanged(MySqlParameter p, string oldName, string newName)
      {
        int index = IndexOf(oldName);
        indexHashCS.Remove(oldName);
        indexHashCI.Remove(oldName);
  
        indexHashCS.Add(newName, index);
        indexHashCI.Add(newName, index);
      }
  
      private MySqlParameter InternalAdd(MySqlParameter value, int index)
      {
        if (value == null)
          throw new ArgumentException("The MySqlParameterCollection only accepts non-null MySqlParameter type objects.", "value");
  
        // if the parameter is unnamed, then assign a default name
        if (String.IsNullOrEmpty(value.ParameterName))
          value.ParameterName = String.Format("Parameter{0}", GetNextIndex());
  
        // make sure we don't already have a parameter with this name
        if (IndexOf(value.ParameterName) >= 0)
        {
          throw new MySqlException(
              String.Format("Resources.ParameterAlreadyDefined", value.ParameterName));
        }
        else
        {
          string inComingName = value.ParameterName;
          if (inComingName[0] == '@' || inComingName[0] == '?')
            inComingName = inComingName.Substring(1, inComingName.Length - 1);
          if (IndexOf(inComingName) >= 0)
            throw new MySqlException(
                String.Format("Resources.ParameterAlreadyDefined", value.ParameterName));
  
  	  }
  
        if (index == -1)
        {
          items.Add(value);
          index = items.Count - 1;
        }
        else
        {
          items.Insert(index, value);
          AdjustHashes(index, true);
        }
  
        indexHashCS.Add(value.ParameterName, index);
        indexHashCI.Add(value.ParameterName, index);
  
        value.Collection = this;
        return value;
      }
  
      private int GetNextIndex()
      {
        int index = Count+1;
  
        while (true)
        {
          string name = "Parameter" + index.ToString();
          if (!indexHashCI.ContainsKey(name)) break;
          index++;
        }
        return index;
      }
  
      private static void AdjustHash(Dictionary<string,int> hash, string parameterName, int keyIndex, bool addEntry)
      {
        if (!hash.ContainsKey(parameterName)) return;
        int index = (int)hash[parameterName];
        if (index < keyIndex) return;
        hash[parameterName] = addEntry ? ++index : --index;
      }
  
      /// <summary>
      /// This method will update all the items in the index hashes when
      /// we insert a parameter somewhere in the middle
      /// </summary>
      /// <param name="keyIndex"></param>
      /// <param name="addEntry"></param>
      private void AdjustHashes(int keyIndex, bool addEntry)
      {
        for (int i = 0; i < Count; i++)
        {
          string name = (items[i] as MySqlParameter).ParameterName;
          AdjustHash(indexHashCI, name, keyIndex, addEntry);
          AdjustHash(indexHashCS, name, keyIndex, addEntry);
        }
      }
  
      private MySqlParameter GetParameterFlexibleInternal(string baseName)
      {
        int index = IndexOf(baseName);
        if (-1 == index)
          index = IndexOf("?" + baseName);
        if (-1 == index)
          index = IndexOf("@" + baseName);
        if (-1 != index)
          return this[index];
        return null;
      }
  
      internal MySqlParameter GetParameterFlexible(string parameterName, bool throwOnNotFound)
      {
        string baseName = parameterName;
  
gt:       MySqlParameter p = GetParameterFlexibleInternal(baseName);