using Microsoft.Practices.EnterpriseLibrary.Data;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;

namespace DataAccessLayer
{
    public static class ConnectionPool
    {
        private static List<SingleConnection> connectionPool = new List<SingleConnection>();
        private static object poolAccessLock = new object();
        public static void InitializePool(List<Tuple<string, bool, int>> poolRecords)
        {
            for (int i = 0; i < poolRecords.Count; i++)
            {
                string connectionString = poolRecords[i].Item1;
                bool isOracleDb = poolRecords[i].Item2;
                int amount = poolRecords[i].Item3;
                for (int j = 0; j < amount; j++)
                {
                    connectionPool.Add(new SingleConnection(connectionString, isOracleDb));
                }
            }
        }
        public static SingleConnection GetDataBase(DBProvider dbProvider)
        {
            string connString = string.Empty;
            bool oracleDb = false;

            switch (dbProvider)
            {
                case DBProvider.SqlServer:
                    connString = WebConfigParameter.getConnectionString("SqlServerConnection");
                    break;
                case DBProvider.SqlServerStampeC6:
                    connString = WebConfigParameter.getConnectionString("SqlServerStampeC6Connection");
                    break;
                case DBProvider.SqlServerConsulenzaBase:
                    connString = WebConfigParameter.getConnectionString("SqlServerConnectionConsulenzaBase");
                    break;
                case DBProvider.SqlServerConsulenzaUnica:
                    connString = WebConfigParameter.getConnectionString("SqlServerConsulenzaUnicaConnection");
                    break;
                case DBProvider.SqlServerConsulenzaEvoluta:
                    connString = WebConfigParameter.getConnectionString("SqlServerConsulenzaEvolutaConnection");
                    break;
                case DBProvider.SqlServerCatalogoProdotti:
                    connString = WebConfigParameter.getConnectionString("SqlServerCatalogoProdottiConnection");
                    break;
                case DBProvider.SqlServerReportModeler:
                    connString = WebConfigParameter.getConnectionString("SqlServerConnectionReportModeler");
                    break;
                case DBProvider.SqlServerWebTemplateReportModeler:
                    connString = WebConfigParameter.getConnectionString("SqlServerConnectionWebTemplateReportModeler");
                    break;
                case DBProvider.SqlServerReportArchive:
                    connString = WebConfigParameter.getConnectionString("SqlServerConnectionReportArchive");
                    break;
                case DBProvider.Oracle:
                    connString = WebConfigParameter.getConnectionString("OracleConnection");
                    oracleDb = true;
                    break;
            }
            while (true)
            {                
                lock (poolAccessLock)
                {
                    foreach (SingleConnection sqc in connectionPool)
                    {
                        if (!sqc.IsInUse &&
                            sqc.ConnectionString == connString &&
                            sqc.IsOracleDb == oracleDb)
                        {
                            sqc.IsInUse = true;
                            return sqc;
                        }
                    }
                }
                Thread.Sleep(20);
            }
        }
    }
}