prs/prs.server/Engines/Database/DatabaseEngine.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography.X509Certificates;
using System.Timers;
using Comal.Classes;
using Comal.Stores;
using InABox.API;
using InABox.Configuration;
using InABox.Core;
using InABox.Database;
using InABox.Database.SQLite;
using InABox.IPC;
using InABox.Rpc;
using InABox.Server;
using InABox.Wpf.Reports;
using PRS.Shared;
using PRSServices;
using Timer = System.Timers.Timer;

namespace PRSServer;

public class DatabaseEngine : Engine<DatabaseServerProperties>
{
    private Timer? _certificateRefreshTimer;
    private Timer? _certificateHaltTimer;

    private string _rpcPipeName = "";
    private InternalServer? _server;

    private string _rpcProxyName = "";
    private IRpcServer? _pipeServer;

    public override void Configure(Server server)
    {
        base.Configure(server);
        Logger.Send(LogType.Information, "", "Configuring...");

        _rpcPipeName = DatabaseServerProperties.GetPipeName(server.Key, true);
        _rpcProxyName = DatabaseServerProperties.GetProxyName(server.Key);

        MoveUpdateFiles();
    }

    public override PortStatus[] PortStatusList()
    {
        var result = new List<PortStatus>();
        if (Properties.Port != 0)
        {
            result.Add(RestListener.Certificate != null
                ? new PortStatus(Properties.Port, PortType.Database, PortState.Secure)
                : new PortStatus(Properties.Port, PortType.Database, PortState.Available));
        }
        if (Properties.RPCPort != 0)
            result.Add(new PortStatus(Properties.RPCPort, PortType.Session, PortState.Available));
        return result.ToArray();
    }

    private void ConfigureSmsProviders()
    {
        if (Properties.SMSProviderProperties == null) return;
        if (Properties.SMSProviderProperties.Count == 0)
        {
            Logger.Send(LogType.Information, "", "No SMS Providers to initialise");
        }
        foreach (var (type, properties) in Properties.SMSProviderProperties)
        {
            var provider = SMSProviderProperties.ToProperties(type, properties);
            switch (provider)
            {
                case ExchangeProviderProperties exchange:
                    Logger.Send(LogType.Information, "", "Initializing Exchange Mailer");
                    CredentialsCache.AddSMSProvider(new ExchangeProvider(
                        exchange.Host,
                        exchange.Port,
                        exchange.EmailAddress,
                        exchange.Password
                    ));
                    break;
                case IMAPProviderProperties imap:
                    Logger.Send(LogType.Information, "", "Initializing IMAP Mailer");
                    CredentialsCache.AddSMSProvider(new IMAPProvider(
                        imap.Host,
                        imap.Port,
                        imap.EmailAddress,
                        imap.Password
                    ));
                    break;
                case ASPSMSProviderProperties asp:
                    Logger.Send(LogType.Information, "", "Initializing ASPSMS");
                    CredentialsCache.AddSMSProvider(new ASPSMSProvider(
                        asp.Userkey,
                        asp.APIPassword
                    ));
                    break;
                case TwilioProviderProperties tw:
                    Logger.Send(LogType.Information, "", "Initializing Twilio");
                    CredentialsCache.AddSMSProvider(new TwilioSMSProvider(
                        tw.AccountSID,
                        tw.AuthToken,
                        tw.Number
                    ));
                    break;
            }
        }
    }

    private IEnumerable<Notification> PollNotifications(Guid session)
    {
        var user = CredentialsCache.Validate(session);
        if (user == null)
            return Array.Empty<Notification>();
        var store = DbFactory.FindStore<Notification>(user.ID, user.UserID, Platform.DatabaseEngine, "");
        return store.Query(
            new Filter<Notification>(x => x.Employee.UserLink.ID).IsEqualTo(user.ID)
                .And(x => x.Closed).IsEqualTo(DateTime.MinValue),
            new Columns<Notification>(
                x => x.ID,
                x => x.Title,
                //x => x.Description,
                x => x.Created,
                x => x.Sender.ID,
                x => x.Sender.Name,
                x => x.Job.ID,
                x => x.Job.Deleted,
                x => x.Job.JobNumber,
                //x => x.Kanban.ID,
                //x => x.Setout.ID,
                //x => x.Requisition.ID,
                //x => x.Delivery.ID,
                x => x.Employee.ID,
                x => x.EntityType,
                x => x.EntityID,
                x => x.Closed
            )).Rows.Select(x => x.ToObject<Notification>());
    }
    
    #region Run/Stop Functionality

    public override void Run()
    {
        Logger.Send(LogType.Information, "", "Starting..");
        
        if (string.IsNullOrEmpty(Properties.FileName))
            throw new Exception("Error: Filename not Specified\n");

        Logger.Send(LogType.Information, "", "Registering Classes: " + Properties.FileName);

        StoreUtils.RegisterClasses();
        CoreUtils.RegisterClasses();
        ComalUtils.RegisterClasses();
        PRSSharedUtils.RegisterClasses();
        ReportUtils.RegisterClasses();
        ConfigurationUtils.RegisterClasses();

        DatabaseUpdateScripts.RegisterScripts();

        Logger.Send(LogType.Information, "", "Starting Database: " + Properties.FileName);

        DbFactory.Stores = CoreUtils.TypeList(
            AppDomain.CurrentDomain.GetAssemblies(),
            myType =>
                myType is { IsClass: true, IsAbstract: false, IsGenericType: false } 
                && myType.GetInterfaces().Contains(typeof(IStore))
        ).ToArray();

        DbFactory.Provider = new SQLiteProvider(Properties.FileName);

        DbFactory.ColorScheme = Properties.ColorScheme;
        DbFactory.Logo = Properties.Logo;
        
        // See notes on Request.DatabaseInfo Class
        // Once RPC listeners are stable, this should be removed.
        DbFactory.RestPort = Properties.Port;
        DbFactory.RPCPort = Properties.RPCPort;

        DbFactory.Start();

        UserStore.PasswordExpirationTime = TimeSpan.FromDays(Properties.PasswordExpiryTime);
        RestService.CheckPasswordExpiration = Properties.PasswordExpiryTime > 0;

        var users = DbFactory.Provider.Load<User>();
        if (!users.Any())
        {
            var user = new User { UserID = "ADMIN", Password = "admin" };
            DbFactory.Provider.Save(user);

            var employee = DbFactory.Provider.Load(new Filter<Employee>(x => x.Code).IsEqualTo("ADMIN")).FirstOrDefault() 
                           ?? new Employee { Code = "ADMIN", Name = "Administrator Account" };
            employee.UserLink.ID = user.ID;
            DbFactory.Provider.Save(employee);
        }

        StoreUtils.GoogleAPIKey = Properties.GoogleAPIKey;
        PurchaseOrder.PONumberPrefix = Properties.PurchaseOrderPrefix;
        Job.JobNumberPrefix = Properties.JobPrefix;

        ConfigureSmsProviders();
        CredentialsCache.SetCacheFile(Path.Combine(AppDataFolder, "session_cache.json"));
        CredentialsCache.LoadSessionCache();
        CredentialsCache.SetSessionExpiryTime(TimeSpan.FromMinutes(Properties.SessionExpiryTime));

        Start();

    }

    private void Start()
    {
        var certificate = LoadCertificate(CertificateFileName());
        if (certificate != null)
        {
            // Once every day, check certificate expiry
            if (_certificateRefreshTimer == null)
            {
                _certificateRefreshTimer = new Timer(1000 * 60 * 60 * 24);
                _certificateRefreshTimer.Elapsed += CertificateTimer_Elapsed;
                _certificateRefreshTimer.AutoReset = true;
            }
            _certificateRefreshTimer.Start();
        }

        _server = new InternalServer(_rpcProxyName);
        PushManager.AddPusher(_server);
        _server.OnLog += (type, userid, message, parameters) => Logger.Send(type, userid, message, parameters);
        _server.Start();

        var transport = new RpcServerPipeTransport(_rpcPipeName);
        _pipeServer = new RpcServer<RpcServerPipeTransport>(transport);
        PushManager.AddPusher(transport);
        _pipeServer.OnLog += (type, userid, message, parameters) => Logger.Send(type, userid, message, parameters);
        _pipeServer.Start();

        PushManager.AddPollHandler(PollNotifications);
        Logger.Send(LogType.Information, "", $"- Push Notifications Configured");
    }
    
    public override void Stop()
    {
        Logger.Send(LogType.Information, "", "Stopping..");
        
        _server?.Stop();
        _server?.Dispose();
        _server = null;
        
        _pipeServer?.Stop();
        _pipeServer = null;

        RestListener.Stop();
        CredentialsCache.SaveSessionCache();

        _certificateRefreshTimer?.Stop();
        _certificateRefreshTimer = null;
        
        _certificateHaltTimer?.Stop();
        _certificateHaltTimer = null;
    }

    #endregion
    
    #region Certificate Management

    private string CertificateFileName() =>
        !string.IsNullOrWhiteSpace(Properties.CertificateFile)
        ? Properties.CertificateFile
        : CertificateEngine.CertificateFile;
    

    private void SendCertificateExpiryNotification(DateTime expiry)
    {
        var message = expiry.Date == DateTime.Now.Date 
            ? $"HTTPS Certificate for Database Engine will expire today at {expiry.TimeOfDay:hh\\:mm}" 
            : $"HTTPS Certificate for Database Engine will expire in {(expiry - DateTime.Now).Days} at {expiry:dd/MM/yyyy hh:mm}";
        
        Logger.Send(LogType.Information, "DATABASE", message);
        if (!string.IsNullOrWhiteSpace(Properties.CertificateExpirationSubscriber))
        {
            var employee = DbFactory.Provider.Query(
                new Filter<Employee>(x => x.UserLink.UserID).IsEqualTo(Properties.CertificateExpirationSubscriber),
                new Columns<Employee>(x => x.ID, x => x.UserLink.ID, x => x.UserLink.UserID)).Rows.FirstOrDefault()?.ToObject<Employee>();
            if (employee != null)
            {
                var notification = new Notification();
                notification.Employee.ID = employee.ID;
                notification.Title = "HTTPS Certificate expires soon";
                notification.Description = message;
                DbFactory.FindStore<Notification>(employee.UserLink.ID, employee.UserLink.UserID, Platform.DatabaseEngine, "")
                    .Save(notification, "");
            }
            else
            {
                Logger.Send(LogType.Information, "DATABASE", $"Certificate expiration subscriber {Properties.CertificateExpirationSubscriber} employee doesn't exist");
            }
        }
    }

    private void CertificateTimer_Elapsed(object? sender, ElapsedEventArgs e)
    {
        if (RestListener.Certificate != null)
        {
            X509Certificate2? cert = null;
            if (File.Exists(CertificateFileName()))
            {
                cert = new X509Certificate2(CertificateFileName());
            }

            if (cert != null && cert.NotAfter > RestListener.Certificate.NotAfter && cert.NotAfter > DateTime.Now)
            {
                Logger.Send(LogType.Information, "DATABASE", "HTTPS Certificate with greater expiry date found; restarting HTTPS listener...");
                Stop();
                Start();
            }

            var expiry = RestListener.Certificate.NotAfter;
            var untilExpiry = expiry - DateTime.Now;
            if (untilExpiry.TotalDays <= 7)
            {
                SendCertificateExpiryNotification(expiry);
                if (untilExpiry.TotalDays <= 1)
                {
                    _certificateRefreshTimer?.Stop();

                    _certificateHaltTimer = new Timer(untilExpiry.TotalMilliseconds);
                    _certificateHaltTimer.Elapsed += HTTPS_Halt_Elapsed;
                    _certificateHaltTimer.AutoReset = false;
                    _certificateHaltTimer.Start();
                }
            }
        }
    }

    /// <summary>
    /// Restarts listener in HTTP mode
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    private void HTTPS_Halt_Elapsed(object? sender, ElapsedEventArgs e)
    {
        _certificateHaltTimer?.Dispose();
        _certificateHaltTimer = null;

        Logger.Send(LogType.Information, "", "Expiry of certificate reached; restarting HTTPS listener...");
        Stop();
        Start();
    }

    #endregion

    #region Desktop Installer Files

    private static bool CheckNewer(string filename)
    {
        var source = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "update", filename);
        var target = Path.Combine(CoreUtils.GetCommonAppData("PRSServer"), "update", filename);
        if (!File.Exists(target)) return true;
        if (!File.Exists(source)) return false;

        return File.GetLastWriteTimeUtc(source) > File.GetLastWriteTimeUtc(target);
    }
    private static void CopyFile(string filename)
    {
        var source = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "update", filename);

        var targetdir = Path.Combine(CoreUtils.GetCommonAppData("PRSServer"), "update");
        if (!Directory.Exists(targetdir))
            Directory.CreateDirectory(targetdir);
        var target = Path.Combine(targetdir, filename);

        File.Copy(source, target, true);
    }
    public static void MoveUpdateFiles()
    {
        try
        {
            if (CheckNewer("version.txt") || CheckNewer("Release Notes.txt") || CheckNewer("PRSDesktopSetup.exe"))
            {
                CopyFile("version.txt");
                CopyFile("Release Notes.txt");
                CopyFile("PRSDesktopSetup.exe");
            }
        }
        catch (Exception e)
        {
            Logger.Send(LogType.Error, "", $"Could not copy desktop update files: {e.Message}");
        }
    }

    #endregion
    
}