using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Odbc;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Linq;
using System.Net;
using System.Text;

namespace Neo.Afx.ComponentModel
{
    /// <summary>
    /// Groups some functionality to test connections to either a Database or Web Service.
    /// </summary>
    public static class Connection
    {
        #region TryConnect
        /// <summary>
        /// A method for attempting to connect to a DB Server or WebService
        /// </summary>
        /// <param name="connectionTypeID"></param>
        /// <param name="connectionString"></param>
        /// <param name="authTypeID"></param>
        /// <param name="authDomain"></param>
        /// <param name="authUser"></param>
        /// <param name="authPassword"></param>
        /// <param name="errorMessage"></param>
        /// <returns></returns>
        public static bool TryConnect(short connectionTypeID, string connectionString, short authTypeID, string authDomain, string authUser, string authPassword, out string errorMessage)
        {
            errorMessage = "";

            try
            {
                switch (connectionTypeID)
                {
                    case 1: //SQL Server
                        TryDbConnect(new SqlConnection(connectionString), out errorMessage);
                        break;
                    case 2: // OLE DB
                        TryDbConnect(new OleDbConnection(connectionString), out errorMessage);
                        break;
                    case 3: // ODBC
                    case 4: // Oracle
                        TryDbConnect(new OdbcConnection(connectionString), out errorMessage);
                        break;
                    case 5: // Web

                        var request = WebRequest.Create(connectionString) as HttpWebRequest;

                        if (request != null)
                        {
                            if (authTypeID == 2) // NetworkCredential
                            {
                                request.Credentials = new NetworkCredential(authUser, authPassword, authDomain);
                            }

                            using (var response = request.GetResponse() as HttpWebResponse)
                            {
                                if (response != null)
                                {
                                    if (response.StatusCode != HttpStatusCode.OK)
                                    {
                                        errorMessage = "Connection Failed - Error locating web service: " + response.StatusDescription;
                                    }
                                }
                                else
                                {
                                    errorMessage = "Connection Failed - Response is NULL";
                                }
                            }
                        }
                        else
                        {
                            errorMessage = "Connection Failed - Request is NULL";
                        }
                        break;
                }
            }
            catch (Exception ex)
            {
                errorMessage = "Connection Failed - " + ex.Message;
            }

            return errorMessage.Trim().Length == 0;
        } 
        #endregion

        #region TryDbConnect
        /// <summary>
        /// Method for attempting to connect to any connection that Inherits from IDBConnection
        /// </summary>
        /// <param name="dbConnection">An IDbConnection to a database</param>
        /// <param name="errorMessage">An out parameter that contains an error message should there be one</param>
        /// <returns></returns>
        private static bool TryDbConnect(IDbConnection dbConnection, out string errorMessage)
        {
            errorMessage = "";

            using (var connection = dbConnection)
            {
                try
                {
                    connection.Open();
                    connection.Close();
                }
                catch (Exception ex)
                {
                    errorMessage = "Connection Failed - " + ex.Message;
                }
            }

            return errorMessage.Trim().Length == 0;
        } 
        #endregion
    }
}