通知中心游标分页

src/Jiaowu.Api/Controllers/WarningsController.cs

@@ -138,15 +138,17 @@ public sealed class WarningsController(AppDbContext db, ICurrentUserDataScope sc
 
     [HttpGet("records")]
     [Authorize(Roles = Managers + "," + SystemRoles.Counselor)]
-    public async Task<ActionResult<PagedResult<WarningRecordListItem>>> GetRecords(
+    public async Task<ActionResult<CursorPagedResult<WarningRecordListItem>>> GetRecords(
         Guid? academicTermId,
         WarningType? type,
-        int page = 1,
+        string? cursor = null,
         int pageSize = 20,
         CancellationToken ct = default)
     {
-        if (page < 1 || pageSize is < 1 or > 100)
-            return ValidationProblem("页码必须大于 0，且每页条数应在 1 至 100 之间。");
+        if (pageSize is < 1 or > 100)
+            return ValidationProblem("每批条数应在 1 至 100 之间。");
+        if (!CursorToken.TryDecode<WarningCursor>(cursor, out var after))
+            return BadRequest("预警记录游标无效。");
 
         var q = db.WarningRecords.AsNoTracking().AsQueryable();
         if (scope.Current.Scope == DataScope.College || scope.Current.IsInRole(SystemRoles.Counselor))
@@ -160,12 +162,15 @@ public sealed class WarningsController(AppDbContext db, ICurrentUserDataScope sc
         if (academicTermId.HasValue) q = q.Where(x => x.AcademicTermId == academicTermId);
         if (type.HasValue) q = q.Where(x => x.Type == type);
 
-        var total = await q.CountAsync(ct);
-        var items = await q
+        if (after is not null)
+        {
+            q = q.Where(x => x.CreatedAt < after.CreatedAt ||
+                x.CreatedAt == after.CreatedAt && x.Id.CompareTo(after.Id) < 0);
+        }
+        var rows = await q
             .OrderByDescending(x => x.CreatedAt)
             .ThenByDescending(x => x.Id)
-            .Skip((page - 1) * pageSize)
-            .Take(pageSize)
+            .Take(pageSize + 1)
             .Select(x => new WarningRecordListItem(
                 x.Id,
                 x.StudentId,
@@ -180,9 +185,20 @@ public sealed class WarningsController(AppDbContext db, ICurrentUserDataScope sc
                 x.AcknowledgeComment,
                 x.CreatedAt))
             .ToListAsync(ct);
-        return Ok(new PagedResult<WarningRecordListItem>(items, total, page, pageSize));
+        var hasMore = rows.Count > pageSize;
+        var items = rows.Take(pageSize).ToArray();
+        var last = items.LastOrDefault();
+        return Ok(new CursorPagedResult<WarningRecordListItem>(
+            items,
+            hasMore && last is not null
+                ? CursorToken.Encode(new WarningCursor(last.CreatedAt, last.Id))
+                : null,
+            hasMore,
+            pageSize));
     }
 
+    private sealed record WarningCursor(DateTime CreatedAt, Guid Id);
+
     // ═══════════ Student ═══════════
     [HttpGet("my-warnings")]
     [Authorize(Roles = SystemRoles.Student)]