// Copyright (C) 2025, The Duplicati Team
// https://duplicati.com, hello@duplicati.com
// 
// Permission is hereby granted, free of charge, to any person obtaining a 
// copy of this software and associated documentation files (the "Software"), 
// to deal in the Software without restriction, including without limitation 
// the rights to use, copy, modify, merge, publish, distribute, sublicense, 
// and/or sell copies of the Software, and to permit persons to whom the 
// Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in 
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.

using System;
using System.Linq;
using System.Collections.Generic;
using System.Security.Cryptography;
using Duplicati.Library.RestAPI;
using System.Text.Json;
using System.Text;
using System.Security.Cryptography.X509Certificates;
using Duplicati.Library.Utility;
using Duplicati.Library.AutoUpdater;
using Microsoft.Extensions.DependencyInjection;
using Duplicati.WebserverCore.Abstractions;
using Duplicati.Library.Snapshots;

#nullable enable

namespace Duplicati.Server.Database
{
    public class ServerSettings
    {
        public static class CONST
        {
            public const string STARTUP_DELAY = "startup-delay";
            public const string DOWNLOAD_SPEED_LIMIT = "max-download-speed";
            public const string UPLOAD_SPEED_LIMIT = "max-upload-speed";
            public const string LAST_WEBSERVER_PORT = "last-webserver-port";
            public const string IS_FIRST_RUN = "is-first-run";
            public const string SERVER_PORT_CHANGED = "server-port-changed";
            public const string SERVER_PASSPHRASE = "server-passphrase";
            public const string SERVER_PASSPHRASE_SALT = "server-passphrase-salt";
            public const string UPDATE_CHECK_LAST = "last-update-check";
            public const string UPDATE_CHECK_INTERVAL = "update-check-interval";
            public const string UPDATE_CHECK_NEW_VERSION = "update-check-latest";
            public const string UNACKED_ERROR = "unacked-error";
            public const string UNACKED_WARNING = "unacked-warning";
            public const string SERVER_LISTEN_INTERFACE = "server-listen-interface";
            public const string SERVER_DISABLE_HTTPS = "server-disable-https";
            public const string SERVER_SSL_CERTIFICATE = "server-ssl-certificate";
            public const string SERVER_SSL_CERTIFICATEPASSWORD = "server-ssl-certificate-password";
            public const string HAS_FIXED_INVALID_BACKUPID = "has-fixed-invalid-backup-id";
            public const string UPDATE_CHANNEL = "update-channel";
            public const string USAGE_REPORTER_LEVEL = "usage-reporter-level";
            public const string DISABLE_TRAY_ICON_LOGIN = "disable-tray-icon-login";
            public const string SERVER_ALLOWED_HOSTNAMES = "allowed-hostnames";
            public const string JWT_CONFIG = "jwt-config";
            public const string REMOTE_CONTROL_CONFIG = "remote-control-config";
            public const string REMOTE_CONTROL_ENABLED = "remote-control-enabled";
            public const string PBKDF_CONFIG = "pbkdf-config";
            public const string AUTOGENERATED_PASSPHRASE = "autogenerated-passphrase";
            public const string DISABLE_VISUAL_CAPTCHA = "disable-visual-captcha";
            public const string DISABLE_SIGNIN_TOKENS = "disable-signin-tokens";
            public const string ENCRYPTED_FIELDS = "encrypted-fields";
            public const string PRELOAD_SETTINGS_HASH = "preload-settings-hash";
            public const string TIMEZONE_OPTION = "server-timezone";
            public const string PAUSED_UNTIL = "paused-until";
            public const string LAST_UPDATE_CHECK_VERSION = "last-update-check-version";
            public const string ADDITIONAL_REPORT_URL = "additional-report-url";
            public const string BACKUP_LIST_SORT_ORDER = "backup-list-sort-order";
            public const string DISABLE_API_EXTENSIONS = "disable-api-extensions";
            public const string POWER_MODE_PROVIDER = "power-mode-provider";
            public const string DISABLE_CONSOLE_CONTROL = "disable-console-control";
        }

        private readonly Dictionary<string, string?> settings;
        private readonly Connection databaseConnection;
        private UpdateInfo? latestUpdate;
        private readonly Action? startOrStopUsageReporter;

        internal ServerSettings(Connection con, Action startOrStopUsageReporter)
        {
            this.startOrStopUsageReporter = startOrStopUsageReporter;
            settings = new Dictionary<string, string?>();
            databaseConnection = con;
            ReloadSettings();

            // Slightly hacky way to set this, but the rest of the code
            // relies on this value, and the database has an override
            // so we sync it here and in the property setter
            if (Enum.TryParse<ReleaseType>(UpdateChannel, true, out var rt))
                UpdaterManager.CurrentChannel = rt;
        }

        public void ReloadSettings()
        {
            lock (databaseConnection.m_lock)
            {
                settings.Clear();
                foreach (var n in typeof(CONST).GetFields(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.DeclaredOnly | System.Reflection.BindingFlags.Static).Select(x => (string?)x.GetValue(null)))
                    if (!string.IsNullOrWhiteSpace(n))
                        settings[n] = null;
                foreach (var n in databaseConnection.GetSettings(Connection.SERVER_SETTINGS_ID))
                    settings[n.Name] = n.Value;
            }
        }

        public void UpdateSettings(Dictionary<string, string?> newsettings, bool clearExisting)
        {
            if (newsettings == null)
                throw new ArgumentNullException(nameof(newsettings));

            lock (databaseConnection.m_lock)
            {
                latestUpdate = null;
                if (clearExisting)
                    settings.Clear();

                foreach (var k in newsettings)
                    if (!clearExisting && newsettings[k.Key] == null && k.Key.StartsWith("--", StringComparison.Ordinal))
                        settings.Remove(k.Key);
                    else
                        settings[k.Key] = newsettings[k.Key];

                // Prevent user from logging themselves out, by disabling the login and not knowing the password
                if (DisableTrayIconLogin && AutogeneratedPassphrase)
                    settings[CONST.DISABLE_TRAY_ICON_LOGIN] = false.ToString();
            }

            SaveSettings();
        }

        private void SaveSettings()
        {
            databaseConnection.SetSettings(
                from n in settings
                select (Duplicati.Server.Serialization.Interface.ISetting)new Setting()
                {
                    Filter = "",
                    Name = n.Key,
                    Value = n.Value
                }, Database.Connection.SERVER_SETTINGS_ID);

            var provider = databaseConnection.ServiceProvider;
            if (provider != null)
            {
                provider?.GetRequiredService<INotificationUpdateService>()?.IncrementLastDataUpdateId();
                provider?.GetRequiredService<EventPollNotify>()?.SignalNewEvent();
                provider?.GetRequiredService<EventPollNotify>()?.SignalServerSettingsUpdated();
                // If throttle options were changed, update now
                provider?.GetRequiredService<IQueueRunnerService>()?.GetCurrentTask()?.UpdateThrottleSpeeds(UploadSpeedLimit, DownloadSpeedLimit);
                provider?.GetRequiredService<LiveControls>()?.UpdatePowerModeProvider();
            }

            // In case the usage reporter is enabled or disabled, refresh now
            startOrStopUsageReporter?.Invoke();
        }

        public string? StartupDelayDuration
        {
            get
            {
                return settings[CONST.STARTUP_DELAY];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.STARTUP_DELAY] = value;
                SaveSettings();
            }
        }

        public DateTime? PausedUntil
        {
            get
            {
                if (long.TryParse(settings[CONST.PAUSED_UNTIL], out var t))
                    return new DateTime(t, DateTimeKind.Utc);
                else
                    return null;
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.PAUSED_UNTIL] = value?.ToUniversalTime().Ticks.ToString();
                SaveSettings();
            }
        }

        public string? DownloadSpeedLimit
        {
            get
            {
                return settings[CONST.DOWNLOAD_SPEED_LIMIT];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.DOWNLOAD_SPEED_LIMIT] = value;
                SaveSettings();
            }
        }

        public string? UploadSpeedLimit
        {
            get
            {
                return settings[CONST.UPLOAD_SPEED_LIMIT];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UPLOAD_SPEED_LIMIT] = value;
                SaveSettings();
            }
        }

        public bool IsFirstRun
        {
            get
            {
                return Utility.ParseBoolOption(settings, CONST.IS_FIRST_RUN);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.IS_FIRST_RUN] = value.ToString();
                SaveSettings();
            }
        }

        public bool UnackedError
        {
            get
            {
                return Utility.ParseBool(settings[CONST.UNACKED_ERROR], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UNACKED_ERROR] = value.ToString();
                SaveSettings();
            }
        }

        public bool UnackedWarning
        {
            get
            {
                return Utility.ParseBool(settings[CONST.UNACKED_WARNING], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UNACKED_WARNING] = value.ToString();
                SaveSettings();
            }
        }

        public bool ServerPortChanged
        {
            get
            {
                return Utility.ParseBool(settings[CONST.SERVER_PORT_CHANGED], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.SERVER_PORT_CHANGED] = value.ToString();
                SaveSettings();
            }
        }

        public bool DisableTrayIconLogin
        {
            get
            {
                return Utility.ParseBool(settings[CONST.DISABLE_TRAY_ICON_LOGIN], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.DISABLE_TRAY_ICON_LOGIN] = value.ToString();
                SaveSettings();
            }
        }

        public bool AutogeneratedPassphrase
        {
            get
            {
                return Utility.ParseBool(settings[CONST.AUTOGENERATED_PASSPHRASE], false);
            }
        }

        public bool DisableSigninTokens
        {
            get
            {
                return Utility.ParseBool(settings[CONST.DISABLE_SIGNIN_TOKENS], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.DISABLE_SIGNIN_TOKENS] = value.ToString();
                SaveSettings();
            }
        }
        public int LastWebserverPort
        {
            get
            {
                var tp = settings[CONST.LAST_WEBSERVER_PORT];
                int p;
                if (string.IsNullOrEmpty(tp) || !int.TryParse(tp, out p))
                    return -1;

                return p;
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.LAST_WEBSERVER_PORT] = value.ToString();
                SaveSettings();
            }
        }

        /// <summary>
        /// Verifies a password against the stored PBKDF configuration
        /// </summary>
        public bool VerifyWebserverPassword(string password)
        {
            var config = settings[CONST.PBKDF_CONFIG];
            if (string.IsNullOrWhiteSpace(password) || string.IsNullOrWhiteSpace(config))
                return false;

            var cfg = JsonSerializer.Deserialize<PbkdfConfig>(config)
                ?? throw new Exception("Unable to deserialize PBKDF configuration");

            return cfg.VerifyPassword(LegacyPreparePassword(password));
        }

        /// <summary>
        /// Prepares a password by pre-hashing it with a legacy salt, if needed
        /// </summary>
        /// <param name="password">The password to hash</param>
        /// <returns>The hashed password</returns>
        private string LegacyPreparePassword(string password)
        {
            var salt = settings[CONST.SERVER_PASSPHRASE_SALT];
            if (string.IsNullOrWhiteSpace(salt))
                return password;

            var buf = Convert.FromBase64String(salt);
            var sha256 = SHA256.Create();
            var str = Encoding.UTF8.GetBytes(password);

            sha256.TransformBlock(str, 0, str.Length, str, 0);
            sha256.TransformFinalBlock(buf, 0, buf.Length);
            return Convert.ToBase64String(sha256.Hash ?? throw new CryptographicUnexpectedOperationException("Calculated hash value is null"));
        }

        /// <summary>
        /// Upgrades the password to a PBKDF configuration, if using the legacy password setup
        /// </summary>        
        public void UpgradePasswordToKBDF()
        {
            if (!string.IsNullOrWhiteSpace(settings[CONST.PBKDF_CONFIG]))
                return;

            // Generate a random password if one is not set
            var password = settings[CONST.SERVER_PASSPHRASE];
            var autogenerated = false;
            if (string.IsNullOrWhiteSpace(password))
            {
                password = Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
                settings[CONST.SERVER_PASSPHRASE_SALT] = null;
                autogenerated = true;
            }

            // This will create a new PBKDF2 configuration
            // In case the password already exists in the database,
            // it will need use the pre-salted password as the password
            var config = PbkdfConfig.CreatePBKDF2(password);
            lock (databaseConnection.m_lock)
            {
                settings[CONST.PBKDF_CONFIG] = JsonSerializer.Serialize(config);
                settings[CONST.SERVER_PASSPHRASE] = null;
                settings[CONST.AUTOGENERATED_PASSPHRASE] = autogenerated.ToString();
                if (autogenerated)
                    settings[CONST.DISABLE_TRAY_ICON_LOGIN] = false.ToString();
            }

            SaveSettings();
        }

        /// <summary>
        /// Sets the webserver password
        /// </summary>
        /// <param name="password">The password to set</param>
        public void SetWebserverPassword(string password)
        {
            if (string.IsNullOrWhiteSpace(password))
                throw new Exception("Disabling password protection is not supported");

            var config = PbkdfConfig.CreatePBKDF2(password);
            lock (databaseConnection.m_lock)
            {
                settings[CONST.SERVER_PASSPHRASE] = null;
                settings[CONST.SERVER_PASSPHRASE_SALT] = null;
                settings[CONST.AUTOGENERATED_PASSPHRASE] = false.ToString();
                settings[CONST.PBKDF_CONFIG] = JsonSerializer.Serialize(config);
            }

            SaveSettings();
        }

        public void SetAllowedHostnames(string? allowedHostnames)
        {
            lock (databaseConnection.m_lock)
                settings[CONST.SERVER_ALLOWED_HOSTNAMES] = allowedHostnames;

            SaveSettings();
        }

        public string? AllowedHostnames => settings[CONST.SERVER_ALLOWED_HOSTNAMES];

        public string? JWTConfig
        {
            get => settings[CONST.JWT_CONFIG];
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.JWT_CONFIG] = value;
                SaveSettings();
            }
        }

        /// <summary>
        /// The number of forever tokens that can be created.
        /// A value of -1 means that forever tokens are disabled.
        /// </summary>
        /// <value>The number of forever tokens that can be created.</value>
        /// <remarks>
        /// This setting is not persisted in the database, as it is meant to be a temporary setting.
        /// </remarks>
        private int m_remainingForeverTokens = -1;

        /// <summary>
        /// Enables forever tokens
        /// </summary>
        public void EnableForeverTokens()
        {
            lock (databaseConnection.m_lock)
                if (m_remainingForeverTokens == -1)
                    m_remainingForeverTokens = 1;
        }


        /// <summary>
        /// Consumes a forever token, if available
        /// </summary>
        /// <returns>True if a token was consumed, false if no tokens are available, null if forever tokens are disabled</returns>
        public bool? ConsumeForeverToken()
        {
            lock (databaseConnection.m_lock)
            {
                if (m_remainingForeverTokens == -1)
                    return null;
                if (m_remainingForeverTokens == 0)
                    return false;

                if (m_remainingForeverTokens > 0)
                    m_remainingForeverTokens--;

                return true;
            }
        }

        public string? RemoteControlConfig
        {
            get => settings[CONST.REMOTE_CONTROL_CONFIG];
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.REMOTE_CONTROL_CONFIG] = value;
                SaveSettings();
            }
        }

        public bool RemoteControlEnabled
        {
            get => Utility.ParseBool(settings[CONST.REMOTE_CONTROL_ENABLED], false);
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.REMOTE_CONTROL_ENABLED] = value.ToString();
                SaveSettings();
            }
        }

        public DateTime LastUpdateCheck
        {
            get
            {
                long t;
                if (long.TryParse(settings[CONST.UPDATE_CHECK_LAST], out t))
                    return new DateTime(t, DateTimeKind.Utc);
                else
                    return new DateTime(0, DateTimeKind.Utc);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UPDATE_CHECK_LAST] = value.ToUniversalTime().Ticks.ToString();
                SaveSettings();
            }
        }

        public string UpdateCheckInterval
        {
            get
            {
                var tp = settings[CONST.UPDATE_CHECK_INTERVAL];
                if (string.IsNullOrWhiteSpace(tp))
                    tp = "1W";

                return tp;
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UPDATE_CHECK_INTERVAL] = value;
                SaveSettings();
                databaseConnection?.ServiceProvider?.GetRequiredService<UpdatePollThread>()?.Reschedule();
            }
        }

        public DateTime NextUpdateCheck
        {
            get
            {
                try
                {
                    return Timeparser.ParseTimeInterval(UpdateCheckInterval, LastUpdateCheck);
                }
                catch
                {
                    return LastUpdateCheck.AddDays(7);
                }
            }
        }

        public Library.AutoUpdater.UpdateInfo? UpdatedVersion
        {
            get
            {
                var updateNew = settings[CONST.UPDATE_CHECK_NEW_VERSION];
                if (string.IsNullOrWhiteSpace(updateNew))
                    return null;

                try
                {
                    if (latestUpdate != null)
                        return latestUpdate;

                    using (var tr = new System.IO.StringReader(updateNew))
                        return latestUpdate = Server.Serialization.Serializer.Deserialize<Library.AutoUpdater.UpdateInfo>(tr);
                }
                catch
                {
                }

                return null;
            }
            set
            {
                string? result = null;
                if (value != null)
                {
                    var sb = new StringBuilder();
                    using (var tw = new System.IO.StringWriter(sb))
                        Server.Serialization.Serializer.SerializeJson(tw, value);

                    result = sb.ToString();
                }

                latestUpdate = value;
                lock (databaseConnection.m_lock)
                    settings[CONST.UPDATE_CHECK_NEW_VERSION] = result;

                SaveSettings();
            }
        }

        public string? ServerListenInterface
        {
            get
            {
                return settings[CONST.SERVER_LISTEN_INTERFACE];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.SERVER_LISTEN_INTERFACE] = value;
                SaveSettings();
            }
        }

        public IReadOnlySet<string> DisabledAPIExtensions
        {
            get
            {
                return settings[CONST.DISABLE_API_EXTENSIONS]?
                    .Split(new[] { ',', ';' }, StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
                    .ToHashSet() ?? new HashSet<string>();
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.DISABLE_API_EXTENSIONS] = string.Join(",", value ?? Enumerable.Empty<string>());
                SaveSettings();
            }
        }

        public bool DisableHTTPS
        {
            get
            {
                return Utility.ParseBool(settings[CONST.SERVER_DISABLE_HTTPS], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.SERVER_DISABLE_HTTPS] = value.ToString();
                SaveSettings();
            }
        }

        public bool UseHTTPS
        {
            get
            {
                return !DisableHTTPS && !string.IsNullOrWhiteSpace(settings[CONST.SERVER_SSL_CERTIFICATE]);
            }
        }

        public bool DisableConsoleControl
        {
            get
            {
                return Utility.ParseBool(settings[CONST.DISABLE_CONSOLE_CONTROL], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.DISABLE_CONSOLE_CONTROL] = value.ToString();
                SaveSettings();
            }
        }


        public X509Certificate2Collection? ServerSSLCertificate
        {
            get
            {
                var certificate = settings[CONST.SERVER_SSL_CERTIFICATE];
                if (string.IsNullOrEmpty(certificate))
                    return null;

                return Utility.LoadPfxCertificate(
                    Convert.FromBase64String(certificate),
                    settings[CONST.SERVER_SSL_CERTIFICATEPASSWORD],
                    // Need to allow loading of plain-text certificates for backwards compatibility
                    allowUnsafeCertificateLoad: true
                );
            }
            set
            {
                if (value == null)
                {
                    lock (databaseConnection.m_lock)
                    {
                        settings[CONST.SERVER_SSL_CERTIFICATE] = null;
                        settings[CONST.SERVER_SSL_CERTIFICATEPASSWORD] = null;
                    }
                }
                else
                {
                    if (!value.Any(x => x.HasPrivateKey))
                        throw new ArgumentException("The certificate must have a private key");

                    var password = Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
                    var certdata = Convert.ToBase64String(value.Export(X509ContentType.Pkcs12, password)
                        ?? throw new CryptographicUnexpectedOperationException("Exported certificate data is null"));

                    lock (databaseConnection.m_lock)
                    {
                        settings[CONST.SERVER_SSL_CERTIFICATE] = certdata;
                        settings[CONST.SERVER_SSL_CERTIFICATEPASSWORD] = password;
                    }
                }

                SaveSettings();
            }
        }

        public bool FixedInvalidBackupId
        {
            get
            {
                return Utility.ParseBool(settings[CONST.HAS_FIXED_INVALID_BACKUPID], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.HAS_FIXED_INVALID_BACKUPID] = value.ToString();
                SaveSettings();
            }
        }

        public string? UpdateChannel
        {
            get
            {
                return settings[CONST.UPDATE_CHANNEL];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.UPDATE_CHANNEL] = value;
                SaveSettings();

                if (string.IsNullOrWhiteSpace(value))
                    UpdaterManager.CurrentChannel = AutoUpdateSettings.DefaultUpdateChannel;
                else if (Enum.TryParse<ReleaseType>(value, true, out var rt))
                    UpdaterManager.CurrentChannel = rt;
            }
        }

        public string? UsageReporterLevel
        {
            get
            {
                return settings[CONST.USAGE_REPORTER_LEVEL];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.USAGE_REPORTER_LEVEL] = value;
                SaveSettings();
            }
        }

        public bool EncryptedFields
        {
            get
            {
                return Utility.ParseBool(settings[CONST.ENCRYPTED_FIELDS], false);
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.ENCRYPTED_FIELDS] = value.ToString();
                SaveSettings();
            }
        }

        public string? PreloadSettingsHash
        {
            get
            {
                return settings[CONST.PRELOAD_SETTINGS_HASH];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.PRELOAD_SETTINGS_HASH] = value;
                SaveSettings();
            }
        }

        public TimeZoneInfo Timezone
        {
            get
            {
                var id = settings[CONST.TIMEZONE_OPTION];

                // All times are stored in UTC in the database, prior to introducing the timezone option
                if (string.IsNullOrEmpty(id))
                    return TimeZoneInfo.Utc;

                try
                {
                    if (!string.IsNullOrEmpty(id))
                        return TimeZoneHelper.GetTimeZoneById(id)
                            ?? TimeZoneInfo.Local;
                }
                catch
                {
                }
                return TimeZoneInfo.Local;
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.TIMEZONE_OPTION] = value?.Id;
                SaveSettings();
            }
        }

        public string? LastConfigIssueCheckVersion
        {
            get
            {
                return settings[CONST.LAST_UPDATE_CHECK_VERSION];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.LAST_UPDATE_CHECK_VERSION] = value;
                SaveSettings();
            }
        }

        public string? AdditionalReportUrl
        {
            get
            {
                return settings[CONST.ADDITIONAL_REPORT_URL];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.ADDITIONAL_REPORT_URL] = value;
                SaveSettings();
            }
        }

        public string? BackupListSortOrder
        {
            get
            {
                return settings[CONST.BACKUP_LIST_SORT_ORDER];
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.BACKUP_LIST_SORT_ORDER] = value;
                SaveSettings();
            }
        }

        public PowerModeProvider PowerModeProvider
        {
            get
            {
                var provider = settings[CONST.POWER_MODE_PROVIDER];
                if (Enum.TryParse<PowerModeProvider>(provider, true, out var parsedProvider))
                    return parsedProvider;

                return PowerModeProvider.Default;
            }
            set
            {
                lock (databaseConnection.m_lock)
                    settings[CONST.POWER_MODE_PROVIDER] = value == PowerModeProvider.Default ? null : value.ToString();
                SaveSettings();
            }
        }

    }
}