using Microsoft.EntityFrameworkCore;
using NLog;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MagMan.Data.Admin
{
    /// <summary>
    /// Classe amministrazione Db principale:
    /// - creazione utenti sul Server MySql
    /// - gestione DB/Tabele x identity & gestione multi-tenant
    /// </summary>
    public class DbAdmin : IDisposable
    {
        #region Private Fields

        private static NLog.Logger Log = LogManager.GetCurrentClassLogger();

        #endregion Private Fields

        #region Public Constructors

        public DbAdmin()
        {
        }

        #endregion Public Constructors

        #region Public Methods

        public static bool CheckCreateUser(string username, string pwd, string dbName)
        {
            bool answ = false;
            using (ServerAdminContext adbCtx = new ServerAdminContext())
            {
                // ricerca utente...
                var numUser = adbCtx
                    .UserList
                    .Where(x => x.User == username)
                    .ToList()
                    .Count;
                if (numUser > 0)
                {
                    answ = true;
                }
                if (!answ)
                {
                    // creo utente
                    string sqlCommand = "FLUSH PRIVILEGES;";
                    adbCtx.Database.ExecuteSqlRaw(sqlCommand);
                    sqlCommand = $"CREATE USER '{username}'@'localhost' IDENTIFIED BY '{pwd}';";
                    adbCtx.Database.ExecuteSqlRaw(sqlCommand);
                    sqlCommand = $"GRANT ALL ON *.* TO '{username}'@'localhost';";
                    adbCtx.Database.ExecuteSqlRaw(sqlCommand);
                    sqlCommand = "FLUSH PRIVILEGES;";
                    adbCtx.Database.ExecuteSqlRaw(sqlCommand);
                }
            }
            return answ;
        }

        public static bool CheckCreateCustDb(int nKeyMain)
        {
            bool answ = false;
            string dbName = $"MagMan_{nKeyMain:000000}";
            using (ServerAdminContext adbCtx = new ServerAdminContext())
            {
                // ricerca DB...
                string sqlCommand = $"SHOW DATABASES;";
                var searchDb = adbCtx
                    .DbList
                    .FromSqlRaw(sqlCommand)
                    .ToList();
                // se trovato qualcosa procedo
                if (searchDb != null)
                {
                    var rigaDb = searchDb.Where(x => x.Database.Contains(dbName, StringComparison.InvariantCultureIgnoreCase)).FirstOrDefault();
                    answ = rigaDb != null;
                }
                // altrimenti crea
                if (!answ)
                {
                    // creo DB
                    sqlCommand = $"CREATE DATABASE IF NOT EXISTS {dbName};";
                    adbCtx.Database.ExecuteSqlRaw(sqlCommand);
                }
            }
            return answ;
        }

        public static async Task<bool> MigrateDbIdentity()
        {
            bool answ = false;
            using (IdentityContext dbCtx = new IdentityContext())
            {
                await dbCtx.Database.MigrateAsync();
                answ = true;
            }
            return answ;
        }
        public static async Task<bool> MigrateDbMultiTenant()
        {
            bool answ = false;
            using (MultiTenantContext dbCtx = new MultiTenantContext())
            {
                await dbCtx.Database.MigrateAsync();
                answ = true;
            }
            return answ;
        }

        public void Dispose()
        {
        }

        #endregion Public Methods
    }
}