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//
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using System;
using System.Data.Common;
using System.Collections.Generic;
using System.Collections;
using Sog.Properties;

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 : DbParameterCollection
    {
        readonly List<MySqlParameter> _items = new List<MySqlParameter>();
        private readonly Dictionary<string, int> _indexHashCs;
        private readonly Dictionary<string, int> _indexHashCi;

        // turns to true if any parameter is unnamed
        internal bool containsUnnamedParameters;

        internal MySqlParameterCollection(MySqlCommand cmd)
        {
            this._indexHashCs = new Dictionary<string, int>();
            this._indexHashCi = new Dictionary<string, int>(StringComparer.CurrentCultureIgnoreCase);
            this.containsUnnamedParameters = false;
            this.Clear();
        }

        /// <summary>
        /// Gets the number of MySqlParameter objects in the collection.
        /// </summary>
        public override int Count => this._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 this.InternalGetParameter(index); }
            set { this.InternalSetParameter(index, value); }
        }

        /// <summary>
        /// Gets the <see cref="MySqlParameter"/> with the specified name.
        /// </summary>
        public new MySqlParameter this[string name]
        {
            get { return this.InternalGetParameter(name); }
            set { this.InternalSetParameter(name, value); }
        }

        /// <summary>
        /// Adds a <see cref="MySqlParameter"/> to the <see cref="MySqlParameterCollection"/> with the parameter name, the data type, the column length, and the source column name.
        /// </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>
        /// <param name="sourceColumn">The name of the source column.</param>
        /// <returns>The newly added <see cref="MySqlParameter"/> object.</returns>
        public MySqlParameter Add(string parameterName, MySqlDbType dbType, int size, string sourceColumn)
        {
            return this.Add(new MySqlParameter(parameterName, dbType, size, sourceColumn));
        }

        /// <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 this.InternalAdd(value, null);
        }

        /// <summary>
        /// Adds a parameter and its value.
        /// </summary>
        /// <param name="parameterName">The name of the parameter.</param>
        /// <param name="value">The value of the parameter.</param>
        /// <returns>A <see cref="MySqlParameter"/> object representing the provided values.</returns>
        public MySqlParameter AddWithValue(string parameterName, object value)
        {
            return this.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 this.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 this.Add(new MySqlParameter(parameterName, dbType, size));
        }

        #endregion

        /// <summary>
        /// Removes all items from the collection.
        /// </summary>
        public override void Clear()
        {
            foreach (MySqlParameter p in this._items)
            {
                p.Collection = null;
            }

            this._items.Clear();
            this._indexHashCs.Clear();
            this._indexHashCi.Clear();
        }

        void CheckIndex(int index)
        {
            if (index < 0 || index >= this.Count)
            {
                throw new IndexOutOfRangeException("Parameter index is out of range.");
            }
        }

        private MySqlParameter InternalGetParameter(int index)
        {
            this.CheckIndex(index);
            return this._items[index];
        }

        private MySqlParameter InternalGetParameter(string parameterName)
        {
            int index = this.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 = this.IndexOf(newParameterName);
                    if (index != -1)
                    {
                        return this._items[index];
                    }
                }

                throw new ArgumentException("Parameter '" + parameterName + "' not found in the collection.");
            }

            return this._items[index];
        }

        private void InternalSetParameter(string parameterName, MySqlParameter value)
        {
            int index = this.IndexOf(parameterName);
            if (index < 0)
            {
                throw new ArgumentException("Parameter '" + parameterName + "' not found in the collection.");
            }

            this.InternalSetParameter(index, value);
        }

        private void InternalSetParameter(int index, MySqlParameter value)
        {
            MySqlParameter newParameter = value;
            if (newParameter == null)
            {
                throw new ArgumentException(Resources.NewValueShouldBeMySqlParameter);
            }

            this.CheckIndex(index);
            MySqlParameter p = this._items[index];

            // first we remove the old parameter from our hashes
            this._indexHashCs.Remove(p.ParameterName);
            this._indexHashCi.Remove(p.ParameterName);

            // then we add in the new parameter
            this._items[index] = newParameter;
            this._indexHashCs.Add(value.ParameterName, index);
            this._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 (!this._indexHashCs.TryGetValue(parameterName, out i) &&
              !this._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 this._items.IndexOf(parameter);
        }

        internal void ParameterNameChanged(MySqlParameter p, string oldName, string newName)
        {
            int index = this.IndexOf(oldName);
            this._indexHashCs.Remove(oldName);
            this._indexHashCi.Remove(oldName);

            this._indexHashCs.Add(newName, index);
            this._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}", this.GetNextIndex());
            }

            // make sure we don't already have a parameter with this name
            if (this.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 (this.IndexOf(inComingName) >= 0)
                {
                    throw new MySqlException(
              String.Format(Resources.ParameterAlreadyDefined, value.ParameterName));
                }
            }

            if (index == null)
            {
                this._items.Add(value);
                index = this._items.Count - 1;
            }
            else
            {
                this._items.Insert((int)index, value);
                this.AdjustHashes((int)index, true);
            }

            this._indexHashCs.Add(value.ParameterName, (int)index);
            this._indexHashCi.Add(value.ParameterName, (int)index);

            value.Collection = this;
            return value;
        }

        private int GetNextIndex()
        {
            int index = this.Count + 1;

            while (true)
            {
                string name = "Parameter" + index.ToString();
                if (!this._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 = 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 < this.Count; i++)
            {
                string name = this._items[i].ParameterName;
                AdjustHash(this._indexHashCi, name, keyIndex, addEntry);
                AdjustHash(this._indexHashCs, name, keyIndex, addEntry);
            }
        }

        private MySqlParameter GetParameterFlexibleInternal(string baseName)
        {
            int index = this.IndexOf(baseName);
            if (-1 == index)
            {
                index = this.IndexOf("?" + baseName);
            }

            if (-1 == index)
            {
                index = this.IndexOf("@" + baseName);
            }

            if (-1 != index)
            {
                return this[index];
            }

            return null;
        }

        internal MySqlParameter GetParameterFlexible(string parameterName, bool throwOnNotFound)
        {
            string baseName = parameterName;
            MySqlParameter p = this.GetParameterFlexibleInternal(baseName);
            if (p != null)
            {
                return p;
            }

            if (parameterName.StartsWith("@", StringComparison.Ordinal) || parameterName.StartsWith("?", StringComparison.Ordinal))
            {
                baseName = parameterName.Substring(1);
            }

            p = this.GetParameterFlexibleInternal(baseName);
            if (p != null)
            {
                return p;
            }

            if (throwOnNotFound)
            {
                throw new ArgumentException("Parameter '" + parameterName + "' not found in the collection.");
            }

            return null;
        }

        #region DbParameterCollection Implementation

        /// <summary>
        /// Adds an array of values to the end of the <see cref="MySqlParameterCollection"/>. 
        /// </summary>
        /// <param name="values"></param>
        public override void AddRange(Array values)
        {
            foreach (DbParameter p in values)
            {
                this.Add(p);
            }
        }

        /// <summary>
        /// Retrieve the parameter with the given name.
        /// </summary>
        /// <param name="parameterName"></param>
        /// <returns></returns>
        protected override DbParameter GetParameter(string parameterName)
        {
            return this.InternalGetParameter(parameterName);
        }

        protected override DbParameter GetParameter(int index)
        {
            return this.InternalGetParameter(index);
        }

        protected override void SetParameter(string parameterName, DbParameter value)
        {
            this.InternalSetParameter(parameterName, value as MySqlParameter);
        }

        protected override void SetParameter(int index, DbParameter value)
        {
            this.InternalSetParameter(index, value as MySqlParameter);
        }

        /// <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 index of the new <see cref="MySqlParameter"/> object.</returns>
        public override int Add(object value)
        {
            MySqlParameter parameter = value as MySqlParameter;
            if (parameter == null)
            {
                throw new MySqlException("Only MySqlParameter objects may be stored");
            }

            parameter = this.Add(parameter);
            return this.IndexOf(parameter);
        }

        /// <summary>
        /// Gets a value indicating whether a <see cref="MySqlParameter"/> with the specified parameter name exists in the collection.
        /// </summary>
        /// <param name="parameterName">The name of the <see cref="MySqlParameter"/> object to find.</param>
        /// <returns>true if the collection contains the parameter; otherwise, false.</returns>
        public override bool Contains(string parameterName)
        {
            return this.IndexOf(parameterName) != -1;
        }

        /// <summary>
        /// Gets a value indicating whether a MySqlParameter exists in the collection.
        /// </summary>
        /// <param name="value">The value of the <see cref="MySqlParameter"/> object to find. </param>
        /// <returns>true if the collection contains the <see cref="MySqlParameter"/> object; otherwise, false.</returns>
        /// <overloads>Gets a value indicating whether a <see cref="MySqlParameter"/> exists in the collection.</overloads>
        public override bool Contains(object value)
        {
            MySqlParameter parameter = value as MySqlParameter;
            if (null == parameter)
            {
                throw new ArgumentException("Argument must be of type DbParameter", nameof(value));
            }

            return this._items.Contains(parameter);
        }

        /// <summary>
        /// Copies MySqlParameter objects from the MySqlParameterCollection to the specified array.
        /// </summary>
        /// <param name="array"></param>
        /// <param name="index"></param>
        public override void CopyTo(Array array, int index)
        {
            this._items.ToArray().CopyTo(array, index);
        }

        /// <summary>
        /// Returns an enumerator that iterates through the <see cref="MySqlParameterCollection"/>. 
        /// </summary>
        /// <returns></returns>
        public override IEnumerator GetEnumerator()
        {
            return this._items.GetEnumerator();
        }

        /// <summary>
        /// Inserts a MySqlParameter into the collection at the specified index.
        /// </summary>
        /// <param name="index"></param>
        /// <param name="value"></param>
        public override void Insert(int index, object value)
        {
            MySqlParameter parameter = value as MySqlParameter;
            if (parameter == null)
            {
                throw new MySqlException("Only MySqlParameter objects may be stored");
            }

            this.InternalAdd(parameter, index);
        }

        /// <summary>
        /// Removes the specified MySqlParameter from the collection.
        /// </summary>
        /// <param name="value"></param>
        public override void Remove(object value)
        {
            MySqlParameter p = (value as MySqlParameter);
            p.Collection = null;
            int index = this.IndexOf(p);
            this._items.Remove(p);

            this._indexHashCs.Remove(p.ParameterName);
            this._indexHashCi.Remove(p.ParameterName);
            this.AdjustHashes(index, false);
        }

        /// <summary>
        /// Removes the specified <see cref="MySqlParameter"/> from the collection using the parameter name.
        /// </summary>
        /// <param name="parameterName">The name of the <see cref="MySqlParameter"/> object to retrieve. </param>
        public override void RemoveAt(string parameterName)
        {
            DbParameter p = this.GetParameter(parameterName);
            this.Remove(p);
        }

        /// <summary>
        /// Removes the specified <see cref="MySqlParameter"/> from the collection using a specific index.
        /// </summary>
        /// <param name="index">The zero-based index of the parameter. </param>
        /// <overloads>Removes the specified <see cref="MySqlParameter"/> from the collection.</overloads>
        public override void RemoveAt(int index)
        {
            object o = this._items[index];
            this.Remove(o);
        }

        /// <summary>
        /// Gets an object that can be used to synchronize access to the 
        /// <see cref="MySqlParameterCollection"/>. 
        /// </summary>
        public override object SyncRoot => (this._items as IList).SyncRoot;

        #endregion

    }
}