自选实验项目教师代选

src/Jiaowu.Api/Controllers/ExperimentsController.cs

@@ -1208,6 +1208,106 @@ public sealed class ExperimentsController(
             .ToListAsync(cancellationToken));
     }
 
+    [HttpGet("sessions/{id:guid}/eligible-students")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetProxyBookingStudents(
+        Guid id,
+        string? keyword,
+        CancellationToken cancellationToken)
+    {
+        var session = await LoadManagedSessionAsync(id, cancellationToken);
+        if (session is null) return NotFound();
+        if (!CanManageSession(session)) return Forbid();
+        if (session.ExperimentProject!.ArrangementMode != ExperimentArrangementMode.SelfScheduled)
+            return ConflictProblem("集中安排实验无需代选场次。");
+
+        var bookedStudentIds = await db.ExperimentBookings.AsNoTracking()
+            .Where(x => x.ExperimentProjectId == session.ExperimentProjectId &&
+                        x.Status == ExperimentBookingStatus.Booked)
+            .Select(x => x.StudentId)
+            .ToListAsync(cancellationToken);
+        var normalizedKeyword = string.IsNullOrWhiteSpace(keyword) ? null : keyword.Trim();
+        var roster = await TeachingTaskRosterQuery.LoadForTasksAsync(
+            db, [session.ExperimentProject.TeachingTaskId], cancellationToken);
+        return Ok(roster
+            .Where(x => !bookedStudentIds.Contains(x.StudentId))
+            .Where(x => normalizedKeyword is null ||
+                        x.StudentNumber.Contains(normalizedKeyword) ||
+                        x.Name.Contains(normalizedKeyword) ||
+                        x.ClassName.Contains(normalizedKeyword))
+            .OrderBy(x => x.StudentNumber)
+            .Take(100)
+            .Select(x => new { x.StudentId, x.StudentNumber, x.Name, x.ClassName }));
+    }
+
+    [HttpPost("sessions/{id:guid}/proxy-bookings")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> CreateProxyBooking(
+        Guid id,
+        ProxyExperimentBookingRequest request,
+        CancellationToken cancellationToken)
+    {
+        return await db.ExecuteInRetriableTransactionAsync<ActionResult>(
+            async transaction =>
+            {
+                db.ChangeTracker.Clear();
+                var session = await LoadManagedSessionAsync(id, cancellationToken);
+                if (session is null) return NotFound();
+                if (!CanManageSession(session)) return Forbid();
+                if (session.Status != ExperimentSessionStatus.Scheduled ||
+                    session.ExperimentProject!.Status != ExperimentProjectStatus.Published ||
+                    session.ExperimentProject.ArrangementMode != ExperimentArrangementMode.SelfScheduled)
+                    return ConflictProblem("只能为已发布的自行安排实验场次代选学生。");
+
+                var student = await db.Students.FirstOrDefaultAsync(x =>
+                    x.Id == request.StudentId && x.Status == StudentStatus.Active,
+                    cancellationToken);
+                if (student is null) return ValidationProblem("学生不存在或不在学。");
+                if (!await TeachingTaskRosterQuery.TaskIdsForStudent(db, student.Id)
+                        .ContainsAsync(session.ExperimentProject.TeachingTaskId, cancellationToken))
+                    return ValidationProblem("该学生不在本实验项目的教学任务名单内。");
+
+                var existing = await db.ExperimentBookings.FirstOrDefaultAsync(x =>
+                    x.ExperimentProjectId == session.ExperimentProjectId && x.StudentId == student.Id,
+                    cancellationToken);
+                if (existing?.Status == ExperimentBookingStatus.Booked)
+                    return existing.ExperimentSessionId == session.Id
+                        ? NoContent()
+                        : ConflictProblem("该学生已预约本实验项目的其他场次。");
+
+                var scheduleProblem = await StudentConflictAsync(student.Id, session, cancellationToken);
+                if (scheduleProblem is not null) return ConflictProblem(scheduleProblem);
+                var reservedCount = await db.ExperimentBookings.CountAsync(x =>
+                    x.ExperimentSessionId == session.Id && x.Status == ExperimentBookingStatus.Booked,
+                    cancellationToken);
+                if (reservedCount >= session.Capacity)
+                    return ConflictProblem("该实验场次名额已满，请选择其他时间。");
+
+                if (existing is null)
+                {
+                    db.ExperimentBookings.Add(new ExperimentBooking
+                    {
+                        ExperimentProjectId = session.ExperimentProjectId,
+                        ExperimentSessionId = session.Id,
+                        StudentId = student.Id
+                    });
+                }
+                else
+                {
+                    existing.ExperimentSessionId = session.Id;
+                    existing.Status = ExperimentBookingStatus.Booked;
+                    existing.BookedAt = DateTime.UtcNow;
+                    existing.CancelledAt = null;
+                }
+                session.ReservedCount = reservedCount + 1;
+                await db.SaveChangesAsync(cancellationToken);
+                await transaction.CommitAsync(cancellationToken);
+                return NoContent();
+            },
+            cancellationToken,
+            IsolationLevel.Serializable);
+    }
+
     [HttpPost("sessions/{id:guid}/book")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> Book(
@@ -1604,6 +1704,24 @@ public sealed class ExperimentsController(
             taskIds.Contains(x.TeachingTaskId));
     }
 
+    private Task<ExperimentSession?> LoadManagedSessionAsync(
+        Guid id,
+        CancellationToken cancellationToken) =>
+        db.ExperimentSessions
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.AcademicTerm)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .Include(x => x.Instructors)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+
     private bool CanManageSession(ExperimentSession session)
     {
         var scope = currentUserDataScope.Current;
@@ -1847,6 +1965,8 @@ public sealed record ExperimentSessionRequest(
     [MaxLength(500)] string? Notes,
     [Required, MinLength(1)] IReadOnlyList<Guid>? InstructorTeacherIds = null);
 
+public sealed record ProxyExperimentBookingRequest(Guid StudentId);
+
 public sealed record ExperimentSessionBatchRequest(
     [Required] IReadOnlyList<ExperimentSessionBatchItem> Items);