Send message to INotification API in Optimizely Content Cloud https://optimizely.blog/2023/04/send-notification-to-optimizely-user-from-external-system/

WebhooksNotificationsApiController.cs

using EPiServer;
using EPiServer.Cms.UI.AspNetIdentity;
using EPiServer.Core;
using EPiServer.Logging;
using EPiServer.Notification;
using EPiServer.ServiceLocation;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Epicweb.Optimizely.Blog.Features.Notifications
{
    [ApiController]
    [Route("api/notify")]
    public class WebhooksNotificationsApiController : Controller
    {
        private readonly ILogger _log = LogManager.GetLogger();
        private readonly INotifier _notifier;
        private readonly IContentLoader _contentLoader;
        private readonly UserManager<ApplicationUser> _userManager;
        private readonly RoleManager<IdentityRole> _roleManager;

        public WebhooksNotificationsApiController(INotifier notifier, IContentLoader contentLoader, UserManager<ApplicationUser> userManager, RoleManager<IdentityRole> roleManager)
        {
            _notifier = notifier;
            _contentLoader = contentLoader;
            _userManager = userManager;
            _roleManager = roleManager;
        }

        public class JsonModel {
            public string message { get; set; }
            public string title { get; set; }
            public int contentReference { get; set; }
            public string roleName { get; set; }
            public string userName { get; set; }
        }

        [HttpPost("message")]
        public async Task<IActionResult> GeneralWebhook([FromBody] JsonModel model, string secret = null)
        {
            if (secret != "ChangeThisORReplaceWithSomethingSecure-d34249beae5663213ee3d9")
            {
                return BadRequest("Secret no good");
            }

            if (model.contentReference < 1)
                return BadRequest("ContentReference less then 0");

            try
            {
                var reference = new ContentReference(model.contentReference);
                if (!_contentLoader.TryGet(reference, out IContent content))
                {
                    _log.Error($"Cound not found {model.contentReference}");
                    return NotFound();
                }

                var editasseturl = EPiServer.Editor.PageEditing.GetEditUrl(reference);
                var message = $"{model.message}: <a href={editasseturl} style=\"color:#0000FF;text-decoration:underline;\">{content.Name}</a>";

                await NotifyEditor(model.title, message, model.userName, model.roleName);

                return Ok("success");
            }
            catch (Exception e)
            {
                _log.Error("Cound not deliver expire message: " + model.contentReference, e);
                return new JsonResult(e.Message)
                {
                    StatusCode = StatusCodes.Status500InternalServerError
                };
            }

        }

        private async Task NotifyEditor(string subject, string content, string userName = null, string roleName = null, string type = "WebHook API Integration")
        {
            //type => WebHook API Integration
            //content => <updatemessage><![CDATA[Example message with link: <a href={0} style="color:#0000FF;text-decoration:underline;">{1}</a>]]></updatemessage>

            IEnumerable<INotificationUser> notificationReceivers = await GetUsers(userName, roleName);

            var message = new NotificationMessage
            {
                ChannelName = "EpicwebMessaging",
                TypeName = type,
                Sender = new NotificationUser("WebHook API Integration"), //This user needs to exists "WebHook API Integration"
                Recipients = notificationReceivers,
                Subject = subject,
                Content = content
            };

            _notifier.PostNotificationAsync(message).Wait();
        }
        /// <summary>
        /// if no username, get roles
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="role"></param>
        /// <returns></returns>
        private async Task<IEnumerable<INotificationUser>> GetUsers(string userName = null, string roleName = "WebEditors")
        {
            if (string.IsNullOrEmpty(userName))
            {

                var role = await _roleManager.FindByNameAsync(roleName);
                if (role == null)
                {
                    // Role doesn't exist
                    throw new ContentNotFoundException(roleName);
                }

                var usersInRole = await _userManager.GetUsersInRoleAsync(roleName);

                return (from sUser in usersInRole
                        select new NotificationUser(sUser.UserName))
                            .Cast<INotificationUser>().ToList();
            }
            else
            {
                return new List<NotificationUser>() { new NotificationUser(userName) };
            }
        }
    }
}