///
/// Copyright (c) 2021 Sensus Slovensko a.s.
///
using System;
using NHibernate;
using Common;

namespace TBF
{
    public class DB
    {
        ///
        /// Database related: This object reference is set after a successful user login
        ///
        public static DatabaseSettings CurrentBench;

        /// <summary>
        /// Session factories for regular sessions.
        /// </summary>
        public static ISessionFactory[] SessionFactories = new ISessionFactory[(int)DBKind.Count];

        /// Create a NHibernate session for the given database
        public static ISession CreateSession(DBKind database)
        {
            if (database < 0 || database >= DBKind.Count) return null;

            int ix = (int)database;
            if (SessionFactories[ix] == null)
            {
                SessionFactories[ix] = CreateSessionFactory(database);
            }

            return SessionFactories[ix].OpenSession();
        }

        /// <summary>
        /// NHibernate session factory (to create the database session 'SessionFactory')
        /// </summary>
        /// <returns>A database session</returns>
        static ISessionFactory CreateSessionFactory(DBKind database)
        {
            Common.DBType dbType;
            string connectionString;

            switch (database)
            {
                default:
                case DBKind.Config:
                    dbType = CurrentBench.ProceduresDBSettings.DbType;
                    connectionString = CurrentBench.ProceduresDBSettings.ConnectionString;
                    break;
                case DBKind.Results:
                    dbType = CurrentBench.WaterMetersDBSettings.DbType;
                    connectionString = CurrentBench.WaterMetersDBSettings.ConnectionString;
                    break;
                case DBKind.RemoteConfig:
                    dbType = CurrentBench.UsersDBSettings.DbType;
                    connectionString = CurrentBench.UsersDBSettings.ConnectionString;
                    break;
            }

            return Config.FluentCommon.CreateSessionFactory(database, dbType, connectionString, false);
        }
    }
}