//===============================================================================

// Microsoft patterns & practices Enterprise Library

// Data Access Application Block

//===============================================================================

// Copyright Š Microsoft Corporation.  All rights reserved.

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY

// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT

// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

// FITNESS FOR A PARTICULAR PURPOSE.

//===============================================================================



using System;

using System.Globalization;

using System.Text;

using Microsoft.Practices.EnterpriseLibrary.Data.Properties;



namespace Microsoft.Practices.EnterpriseLibrary.Data

{

	/// <summary>

	/// ConnectionString class constructs a connection string by 

	/// inserting a username and password into a template.

	/// </summary>

	public class ConnectionString

	{

		private const char CONNSTRING_DELIM = ';';

		private string connectionString;

		private string connectionStringWithoutCredentials;

		private string userIdTokens;

		private string passwordTokens;



		/// <summary>

		/// Initializes a new instance of the <see cref="ConnectionString"/> with a connection string, the user ID tokens and password tokens.

		/// </summary>

		/// <param name="connectionString">The connection string.</param>

		/// <param name="userIdTokens">The user id tokens that can be parsed out of the connection string.</param>

		/// <param name="passwordTokens">The password tokens that can be parsed out of the conection string.</param>

		public ConnectionString(string connectionString, string userIdTokens, string passwordTokens)

		{

			if (string.IsNullOrEmpty(connectionString)) throw new ArgumentException(Resources.ExceptionNullOrEmptyString, "connectionString");

			if (string.IsNullOrEmpty(userIdTokens)) throw new ArgumentException(Resources.ExceptionNullOrEmptyString, "userIdTokens");

			if (string.IsNullOrEmpty(passwordTokens)) throw new ArgumentException(Resources.ExceptionNullOrEmptyString, "passwordTokens");



			this.connectionString = connectionString;

			this.userIdTokens = userIdTokens;

			this.passwordTokens = passwordTokens;



			this.connectionStringWithoutCredentials = null;

		}



		/// <summary>

		/// Gets or sets the name of the user.

		/// </summary>

		/// <value>The name of the user.</value>

		/// <devdoc>

		/// Database username for the connection string.

		/// </devdoc>

		public string UserName

		{

			get

			{

                string lowConnString = connectionString.ToLowerInvariant();

				int uidPos;

				int uidMPos;



				GetTokenPositions(userIdTokens, out uidPos, out uidMPos);

				if (0 <= uidPos)

				{

					// found a user id, so pull out the value

					int uidEPos = lowConnString.IndexOf(CONNSTRING_DELIM, uidMPos);

					return connectionString.Substring(uidMPos, uidEPos - uidMPos);

				}

				else

				{

					return String.Empty;

				}

			}

			set

			{

                string lowConnString = connectionString.ToLowerInvariant();

				int uidPos;

				int uidMPos;

				GetTokenPositions(userIdTokens, out uidPos, out uidMPos);

				if (0 <= uidPos)

				{

					// found a user id, so replace the value

					int uidEPos = lowConnString.IndexOf(CONNSTRING_DELIM, uidMPos);

					connectionString = connectionString.Substring(0, uidMPos) +

						value + connectionString.Substring(uidEPos);



					//_connectionStringNoCredentials = RemoveCredentials(_connectionString);

				}

				else

				{

					//no user id in the connection string so just append to the connection string

					string[] tokens = userIdTokens.Split(',');

					connectionString += tokens[0] + value + CONNSTRING_DELIM;

				}

			}

		}



		/// <devdoc>

		/// User password for the connection string.

		/// </devdoc>

		public string Password

		{

			get

			{



				string lowConnString = connectionString.ToLowerInvariant();

				int pwdPos;

				int pwdMPos;

				GetTokenPositions(passwordTokens, out pwdPos, out pwdMPos);



				if (0 <= pwdPos)

				{

					// found a password, so pull out the value

					int pwdEPos = lowConnString.IndexOf(CONNSTRING_DELIM, pwdMPos);

					return connectionString.Substring(pwdMPos, pwdEPos - pwdMPos);

				}

				else

				{

					return String.Empty;

				}

			}

			set

			{

                string lowConnString = connectionString.ToLowerInvariant();

				int pwdPos;

				int pwdMPos;

				GetTokenPositions(passwordTokens, out pwdPos, out pwdMPos);



				if (0 <= pwdPos)

				{

					// found a password, so replace the value

					int pwdEPos = lowConnString.IndexOf(CONNSTRING_DELIM, pwdMPos);

					connectionString = connectionString.Substring(0, pwdMPos) + value + connectionString.Substring(pwdEPos);



					//_connectionStringNoCredentials = RemoveCredentials(_connectionString);

				}

				else

				{

					//no password in the connection string so just append to the connection string

					string[] tokens = passwordTokens.Split(',');

					connectionString += tokens[0] + value + CONNSTRING_DELIM;

				}

			}

		}



		/// <devdoc>

		/// Gets the formatted connection string.

		/// </devdoc>        

		public override string ToString()

		{

			return connectionString;

		}



		/// <devdoc>

		/// Gets the formatted connection string without the username and password.

		/// </devdoc>        

		public string ToStringNoCredentials()

		{

			if (connectionStringWithoutCredentials == null)

				connectionStringWithoutCredentials = RemoveCredentials(connectionString);

			return connectionStringWithoutCredentials;

		}



		/// <summary>

		/// Formats a new connection string with a user ID and password.

		/// </summary>  

		/// <param name="connectionStringToFormat">

		/// The connection string to format.

		/// </param>		

		public ConnectionString CreateNewConnectionString(string connectionStringToFormat)

		{

			return new ConnectionString(connectionStringToFormat, userIdTokens, passwordTokens);

		}



		private void GetTokenPositions(string tokenString, out int tokenPos, out int tokenMPos)

		{

			string[] tokens = tokenString.Split(',');

			int currentPos = -1;

			int previousPos = -1;

            string lowConnString = connectionString.ToLowerInvariant();



			//initialze output parameter

			tokenPos = -1;

			tokenMPos = -1;

			foreach (string token in tokens)

			{

				currentPos = lowConnString.IndexOf(token);

				if (currentPos > previousPos)

				{

					tokenPos = currentPos;

					tokenMPos = currentPos + token.Length;

					previousPos = currentPos;

				}

			}

		}



		private string RemoveCredentials(string connectionStringToModify)

		{

			StringBuilder connStringNoCredentials = new StringBuilder();



            string[] tokens = connectionStringToModify.ToLowerInvariant().Split(CONNSTRING_DELIM);



			string thingsToRemove = userIdTokens + "," + passwordTokens;

            string[] avoidTokens = thingsToRemove.ToLowerInvariant().Split(',');



			foreach (string section in tokens)

			{

				bool found = false;

				string token = section.Trim();

				if (token.Length != 0)

				{

					foreach (string avoidToken in avoidTokens)

					{

						if (token.StartsWith(avoidToken))

						{

							found = true;

							break;

						}

					}

					if (!found)

					{

						connStringNoCredentials.Append(token + CONNSTRING_DELIM);

					}

				}

			}

			return connStringNoCredentials.ToString();

		}

	}

}