btcpayserver/BTCPayServer/HostedServices/CssThemeManager.cs

using System;
using Microsoft.Extensions.Logging;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using BTCPayServer.Logging;
using Microsoft.Extensions.Hosting;
using NBXplorer;
using NBXplorer.Models;
using System.Collections.Concurrent;
using BTCPayServer.Events;
using BTCPayServer.Services;

namespace BTCPayServer.HostedServices
{
    public class CssThemeManager
    {
        public void Update(ThemeSettings data)
        {
            if (String.IsNullOrWhiteSpace(data.BootstrapCssUri))
                _bootstrapUri = "/vendor/bootstrap4/css/bootstrap.css?v=" + DateTime.Now.Ticks;
            else
                _bootstrapUri = data.BootstrapCssUri;


            if (String.IsNullOrWhiteSpace(data.CreativeStartCssUri))
                _creativeStartUri = "/vendor/bootstrap4-creativestart/creative.css?v=" + DateTime.Now.Ticks;
            else
                _creativeStartUri = data.CreativeStartCssUri;
        }

        private string _bootstrapUri;
        public string BootstrapUri
        {
            get { return _bootstrapUri; }
        }

        private string _creativeStartUri;
        public string CreativeStartUri
        {
            get { return _creativeStartUri; }
        }
    }

    public class CssThemeManagerHostedService : BaseAsyncService
    {
        private SettingsRepository _SettingsRepository;
        private CssThemeManager _CssThemeManager;

        public CssThemeManagerHostedService(SettingsRepository settingsRepository, CssThemeManager cssThemeManager)
        {
            _SettingsRepository = settingsRepository;
            _CssThemeManager = cssThemeManager;
        }

        internal override Task[] InitializeTasks()
        {
            return new[]
            {
                CreateLoopTask(ListenForThemeChanges)
            };
        }

        async Task ListenForThemeChanges()
        {
            await new SynchronizationContextRemover();
            var data = (await _SettingsRepository.GetSettingAsync<ThemeSettings>()) ?? new ThemeSettings();
            _CssThemeManager.Update(data);

            await _SettingsRepository.WaitSettingsChanged<ThemeSettings>(Cancellation);
        }
    }
}