选课

README.md

@@ -10,6 +10,14 @@
 
 本地开发固定使用 SQLite。首次启动会自动创建 `src/Jiaowu.Api/data/jiaowu-dev.sqlite` 并写入演示组织数据。
 
+Development 环境还会按业务编码幂等补齐一套大规模测试数据：16 个常见学院或教学单位、52 个常见本科专业、每个专业 2 个 2026 级行政班、每班 35 名学生、每学院 8 名教师，以及覆盖公共必修、公共选修、专业必修、专业选修和实践教学的 150 余门课程。测试教师同时生成当前学期已审核通过的授课资格；重复启动不会重复累加数据，也不会覆盖已有记录。
+
+只执行数据库迁移和测试数据补齐、不启动 Web 服务时，可以运行：
+
+```powershell
+dotnet run --project src/Jiaowu.Api -- --seed-only
+```
+
 ```powershell
 dotnet run --project src/Jiaowu.Api
 ```

src/Jiaowu.Api/Controllers/CourseSelectionsController.cs

@@ -179,6 +179,7 @@ public sealed class CourseSelectionsController(
                 TaskName = x.TeachingTask.Name,
                 CourseCode = x.TeachingTask.Course!.Code,
                 CourseName = x.TeachingTask.Course.Name,
+                CourseNature = x.TeachingTask.Course.Nature,
                 CollegeName = x.TeachingTask.Course.College!.Name,
                 x.TeachingTask.Course.Credits,
                 TeacherNames = x.TeachingTask.Teachers
@@ -279,10 +280,14 @@ public sealed class CourseSelectionsController(
                 x.TeachingTaskId,
                 x.TeachingTask!.TaskNumber,
                 TaskName = x.TeachingTask.Name,
+                CourseCode = x.TeachingTask.Course!.Code,
                 CourseName = x.TeachingTask.Course!.Name,
+                CourseNature = x.TeachingTask.Course.Nature,
                 CollegeId = x.TeachingTask.Course.CollegeId,
                 TeacherUserIds = x.TeachingTask.Teachers
                     .Select(item => item.Teacher!.UserId),
+                x.CourseSelectionRoundId,
+                RoundStatus = x.CourseSelectionRound!.Status,
                 x.Capacity
             })
             .FirstOrDefaultAsync(cancellationToken);
@@ -316,13 +321,281 @@ public sealed class CourseSelectionsController(
             offering.TeachingTaskId,
             offering.TaskNumber,
             offering.TaskName,
+            offering.CourseCode,
             offering.CourseName,
+            offering.CourseNature,
             offering.Capacity,
             EnrolledCount = students.Count,
-            Students = students
+            Students = students,
+            CanProxyEnroll =
+                CourseSelectionRules.SupportsProxyEnrollment(offering.CourseNature) &&
+                offering.RoundStatus != CourseSelectionRoundStatus.Draft &&
+                (currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+                 currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin))
         });
     }
 
+    [HttpGet("offerings/{id:guid}/eligible-students")]
+    [Authorize(Roles = RoundManagers)]
+    public async Task<ActionResult> GetEligibleStudents(
+        Guid id,
+        string? keyword = null,
+        int page = 1,
+        int pageSize = 20,
+        CancellationToken cancellationToken = default)
+    {
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 10, 100);
+        var offering = await db.CourseSelectionOfferings.AsNoTracking()
+            .Where(x => x.Id == id)
+            .Select(x => new
+            {
+                x.Id,
+                x.IsOpenToAll,
+                CourseNature = x.TeachingTask!.Course!.Nature,
+                RoundStatus = x.CourseSelectionRound!.Status,
+                ClassIds = x.TeachingTask.Classes
+                    .Select(item => item.AdministrativeClassId)
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (offering is null) return NotFound();
+        if (!CourseSelectionRules.SupportsProxyEnrollment(offering.CourseNature))
+            return ConflictProblem("管理员代选仅适用于公共必修课。");
+        if (offering.RoundStatus == CourseSelectionRoundStatus.Draft)
+            return ConflictProblem("选课批次开放后才能办理管理员代选。");
+
+        var source = db.Students.AsNoTracking()
+            .Where(x =>
+                x.Status == StudentStatus.Active &&
+                (offering.IsOpenToAll ||
+                 offering.ClassIds.Contains(x.AdministrativeClassId)) &&
+                !db.CourseEnrollments.Any(enrollment =>
+                    enrollment.CourseSelectionOfferingId == id &&
+                    enrollment.StudentId == x.Id &&
+                    enrollment.Status == CourseEnrollmentStatus.Enrolled));
+        if (!string.IsNullOrWhiteSpace(keyword))
+        {
+            keyword = keyword.Trim();
+            source = source.Where(x =>
+                x.StudentNumber.Contains(keyword) ||
+                x.Name.Contains(keyword) ||
+                x.AdministrativeClass!.Name.Contains(keyword));
+        }
+
+        var total = await source.CountAsync(cancellationToken);
+        var items = await source
+            .OrderBy(x => x.StudentNumber)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(x => new
+            {
+                x.Id,
+                x.StudentNumber,
+                x.Name,
+                ClassName = x.AdministrativeClass!.Name,
+                MajorName = x.AdministrativeClass.Major!.Name,
+                CollegeName = x.AdministrativeClass.Major.College!.Name
+            })
+            .ToListAsync(cancellationToken);
+        return Ok(new { Items = items, Total = total, Page = page, PageSize = pageSize });
+    }
+
+    [HttpPost("offerings/{id:guid}/admin-enrollments")]
+    [Authorize(Roles = RoundManagers)]
+    public async Task<ActionResult> AdminEnroll(
+        Guid id,
+        AdminEnrollmentRequest request,
+        CancellationToken cancellationToken)
+    {
+        var studentIds = request.StudentIds.Distinct().ToArray();
+        if (studentIds.Length == 0)
+            return ValidationProblem("请至少选择一名学生。");
+        if (studentIds.Length > 100)
+            return ValidationProblem("单次最多可为 100 名学生代选。");
+
+        await using var transaction = await db.Database.BeginTransactionAsync(
+            IsolationLevel.Serializable,
+            cancellationToken);
+        var offering = await db.CourseSelectionOfferings
+            .Include(x => x.CourseSelectionRound)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Classes)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (offering is null) return NotFound();
+        var round = offering.CourseSelectionRound!;
+        var task = offering.TeachingTask!;
+        if (!CourseSelectionRules.SupportsProxyEnrollment(task.Course!.Nature))
+            return ConflictProblem("管理员代选仅适用于公共必修课。");
+        if (round.Status == CourseSelectionRoundStatus.Draft)
+            return ConflictProblem("选课批次开放后才能办理管理员代选。");
+        if (task.Status != TeachingTaskStatus.Published)
+            return ConflictProblem("该教学班当前不可办理代选。");
+
+        var students = await db.Students
+            .Include(x => x.AdministrativeClass)
+            .Where(x => studentIds.Contains(x.Id))
+            .OrderBy(x => x.StudentNumber)
+            .ToListAsync(cancellationToken);
+        if (students.Count != studentIds.Length)
+            return ValidationProblem("存在无效的学生档案。");
+        var inactive = students.FirstOrDefault(x => x.Status != StudentStatus.Active);
+        if (inactive is not null)
+            return ConflictProblem($"学生 {inactive.StudentNumber} {inactive.Name} 当前不是在籍状态。");
+        var outOfScope = students.FirstOrDefault(student =>
+            !offering.IsOpenToAll &&
+            !task.Classes.Any(item =>
+                item.AdministrativeClassId == student.AdministrativeClassId));
+        if (outOfScope is not null)
+        {
+            return ConflictProblem(
+                $"学生 {outOfScope.StudentNumber} {outOfScope.Name} 不属于该教学班的选课对象。");
+        }
+
+        var existingEnrollments = await db.CourseEnrollments
+            .Where(x =>
+                x.CourseSelectionOfferingId == id &&
+                studentIds.Contains(x.StudentId))
+            .ToListAsync(cancellationToken);
+        var alreadyEnrolled = existingEnrollments.FirstOrDefault(x =>
+            x.Status == CourseEnrollmentStatus.Enrolled);
+        if (alreadyEnrolled is not null)
+        {
+            var student = students.First(x => x.Id == alreadyEnrolled.StudentId);
+            return ConflictProblem(
+                $"学生 {student.StudentNumber} {student.Name} 已在该教学班名单中。");
+        }
+
+        var enrolledCount = await db.CourseEnrollments.CountAsync(
+            x =>
+                x.CourseSelectionOfferingId == id &&
+                x.Status == CourseEnrollmentStatus.Enrolled,
+            cancellationToken);
+        if (enrolledCount + students.Count > offering.Capacity)
+        {
+            return ConflictProblem(
+                $"教学班仅剩 {Math.Max(0, offering.Capacity - enrolledCount)} 个名额，无法完成本次代选。");
+        }
+
+        var duplicateStudentIds = await db.CourseEnrollments.AsNoTracking()
+            .Where(x =>
+                studentIds.Contains(x.StudentId) &&
+                x.Status == CourseEnrollmentStatus.Enrolled &&
+                x.CourseSelectionOffering!.TeachingTask!.CourseId == task.CourseId &&
+                x.CourseSelectionOffering.CourseSelectionRound!.AcademicTermId ==
+                    round.AcademicTermId)
+            .Select(x => x.StudentId)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        if (duplicateStudentIds.Count > 0)
+        {
+            var student = students.First(x => duplicateStudentIds.Contains(x.Id));
+            return ConflictProblem(
+                $"学生 {student.StudentNumber} {student.Name} 本学期已选择相同课程。");
+        }
+
+        var candidateEntries = await PublishedScheduleEntries(
+            round.AcademicTermId,
+            [task.Id],
+            cancellationToken);
+        if (candidateEntries.Count == 0)
+            return ConflictProblem("该教学班尚未发布课表，暂时不能办理代选。");
+
+        foreach (var student in students)
+        {
+            var selectedCredits = await db.CourseEnrollments
+                .Where(x =>
+                    x.StudentId == student.Id &&
+                    x.Status == CourseEnrollmentStatus.Enrolled &&
+                    x.CourseSelectionOffering!.CourseSelectionRoundId == round.Id)
+                .SumAsync(
+                    x => (decimal?)x.CourseSelectionOffering!.TeachingTask!.Course!.Credits,
+                    cancellationToken) ?? 0;
+            if (selectedCredits + task.Course.Credits > round.MaxCredits)
+            {
+                return ConflictProblem(
+                    $"学生 {student.StudentNumber} {student.Name} 代选后将超过本轮 {round.MaxCredits:0.#} 学分上限。");
+            }
+
+            var selectedTaskIds = await db.CourseEnrollments.AsNoTracking()
+                .Where(x =>
+                    x.StudentId == student.Id &&
+                    x.Status == CourseEnrollmentStatus.Enrolled &&
+                    x.CourseSelectionOffering!.CourseSelectionRound!.AcademicTermId ==
+                        round.AcademicTermId)
+                .Select(x => x.CourseSelectionOffering!.TeachingTaskId)
+                .Distinct()
+                .ToArrayAsync(cancellationToken);
+            var selectedEntries = await PublishedScheduleEntries(
+                round.AcademicTermId,
+                selectedTaskIds,
+                cancellationToken);
+            if (CourseSelectionRules.HasScheduleConflict(candidateEntries, selectedEntries))
+            {
+                return ConflictProblem(
+                    $"学生 {student.StudentNumber} {student.Name} 的已选课程与该教学班时间冲突。");
+            }
+        }
+
+        var now = DateTime.UtcNow;
+        foreach (var student in students)
+        {
+            var enrollment = existingEnrollments.FirstOrDefault(x =>
+                x.StudentId == student.Id);
+            if (enrollment is null)
+            {
+                db.CourseEnrollments.Add(new CourseEnrollment
+                {
+                    CourseSelectionOfferingId = id,
+                    StudentId = student.Id,
+                    EnrolledAt = now
+                });
+            }
+            else
+            {
+                enrollment.Status = CourseEnrollmentStatus.Enrolled;
+                enrollment.EnrolledAt = now;
+                enrollment.WithdrawnAt = null;
+            }
+        }
+
+        await db.SaveChangesAsync(cancellationToken);
+        await transaction.CommitAsync(cancellationToken);
+        return Ok(new { EnrolledCount = students.Count });
+    }
+
+    [HttpDelete("offerings/{offeringId:guid}/admin-enrollments/{enrollmentId:guid}")]
+    [Authorize(Roles = RoundManagers)]
+    public async Task<ActionResult> AdminWithdraw(
+        Guid offeringId,
+        Guid enrollmentId,
+        CancellationToken cancellationToken)
+    {
+        var enrollment = await db.CourseEnrollments
+            .Include(x => x.CourseSelectionOffering)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .FirstOrDefaultAsync(
+                x =>
+                    x.Id == enrollmentId &&
+                    x.CourseSelectionOfferingId == offeringId,
+                cancellationToken);
+        if (enrollment is null) return NotFound();
+        var offering = enrollment.CourseSelectionOffering!;
+        if (!CourseSelectionRules.SupportsProxyEnrollment(
+                offering.TeachingTask!.Course!.Nature))
+            return ConflictProblem("管理员名单调整仅适用于公共必修课。");
+        if (offering.TeachingTask.Status != TeachingTaskStatus.Published)
+            return ConflictProblem("该教学班当前不可调整名单。");
+        if (enrollment.Status != CourseEnrollmentStatus.Enrolled)
+            return ConflictProblem("该学生已不在教学班名单中。");
+
+        enrollment.Status = CourseEnrollmentStatus.Withdrawn;
+        enrollment.WithdrawnAt = DateTime.UtcNow;
+        return await SaveAsync(enrollmentId, false, cancellationToken);
+    }
+
     [HttpGet("student/options")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> GetStudentOptions(
@@ -722,6 +995,9 @@ public sealed record CourseSelectionOfferingRequest(
 
 public sealed record StudentEnrollmentRequest(Guid OfferingId);
 
+public sealed record AdminEnrollmentRequest(
+    [MinLength(1)] IReadOnlyCollection<Guid> StudentIds);
+
 public sealed record StudentOfferingDto(
     Guid Id,
     Guid TeachingTaskId,

src/Jiaowu.Api/Infrastructure/CourseSelection/CourseSelectionRules.cs

@@ -14,6 +14,9 @@ public static class CourseSelectionRules
         round.Status == CourseSelectionRoundStatus.Open &&
         nowUtc <= round.WithdrawalEndsAt;
 
+    public static bool SupportsProxyEnrollment(CourseNature nature) =>
+        nature == CourseNature.GeneralRequired;
+
     public static bool HasScheduleConflict(
         IEnumerable<ScheduleEntry> candidateEntries,
         IEnumerable<ScheduleEntry> selectedEntries) =>