feat(notifications): support dismissing notifications in PostIt

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/Yavsc.Api/Controllers/Administration/DismissClicksApiController.cs

@@ -0,0 +1,76 @@
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using Yavsc.Abstract.Models.Messaging;
+using Yavsc.Models;
+using Yavsc.Models.Messaging;
+using Yavsc.Server.Helpers;
+
+namespace Yavsc.ApiControllers.Administration;
+
+/// <summary>
+/// Notifications dismissed by the authenticated user.
+/// </summary>
+[Authorize]
+[Produces("application/json")]
+[Route(Constants.APIPrefix + "/" + Constants.NotificationsDismissPath)]
+public sealed class DismissClicksApiController : Controller
+{
+    private readonly ApplicationDbContext _dbContext;
+
+    public DismissClicksApiController(ApplicationDbContext dbContext)
+    {
+        _dbContext = dbContext;
+    }
+
+    [HttpGet]
+    public async Task<ActionResult<List<DismissedNotification>>> GetDismissed()
+    {
+        var userId = User.GetUserId();
+        var dismissed = await _dbContext.DismissClicked
+            .AsNoTracking()
+            .Where(d => d.UserId == userId)
+            .OrderBy(d => d.NotificationId)
+            .Select(d => new DismissedNotification { NotificationId = d.NotificationId })
+            .ToListAsync();
+        return Ok(dismissed);
+    }
+
+    /// <summary>
+    /// Dismisses a notification for the current user. Idempotent.
+    /// </summary>
+    [HttpPost(Constants.NotificationsDismissClickRoute + "/{notificationId:long}")]
+    public async Task<ActionResult<DismissedNotification>> Click(long notificationId)
+    {
+        var userId = User.GetUserId();
+        if (!await _dbContext.Notification.AnyAsync(n => n.Id == notificationId))
+            return NotFound();
+
+        var exists = await _dbContext.DismissClicked
+            .AnyAsync(d => d.UserId == userId && d.NotificationId == notificationId);
+        if (!exists)
+        {
+            _dbContext.DismissClicked.Add(new DismissClicked { UserId = userId, NotificationId = notificationId });
+            await _dbContext.SaveChangesAsync(userId);
+        }
+
+        return Ok(new DismissedNotification { NotificationId = notificationId });
+    }
+
+    /// <summary>
+    /// Restores a previously dismissed notification for the current user.
+    /// </summary>
+    [HttpDelete(Constants.NotificationsDismissClickRoute + "/{notificationId:long}")]
+    public async Task<IActionResult> Restore(long notificationId)
+    {
+        var userId = User.GetUserId();
+        var dismissed = await _dbContext.DismissClicked
+            .SingleOrDefaultAsync(d => d.UserId == userId && d.NotificationId == notificationId);
+        if (dismissed is null)
+            return NotFound();
+
+        _dbContext.DismissClicked.Remove(dismissed);
+        await _dbContext.SaveChangesAsync(userId);
+        return NoContent();
+    }
+}