Prevent duplicate equivalency rules and support safe deletion

src/Jiaowu.Api/Controllers/CourseEquivalencyRulesController.cs

@@ -40,6 +40,8 @@ public sealed class CourseEquivalencyRulesController(
             return Forbid();
         if (request.MajorId.HasValue && !await db.Majors.AnyAsync(x => x.Id == request.MajorId && (!collegeId.HasValue || x.CollegeId == collegeId), token))
             return ValidationProblem("适用专业不在当前维护范围内。");
+        if (await HasSameScopeRuleAsync(request, null, token))
+            return ConflictProblem();
         var rule = new CourseEquivalencyRule { OriginalCourseId = request.OriginalCourseId, SubstituteCourseId = request.SubstituteCourseId,
             MajorId = request.MajorId, EffectiveGrade = request.EffectiveGrade, IsEnabled = request.IsEnabled, Notes = request.Notes?.Trim() };
         db.CourseEquivalencyRules.Add(rule);
@@ -58,11 +60,48 @@ public sealed class CourseEquivalencyRulesController(
         var collegeId = scope.Current.RestrictedCollegeId;
         if (request.MajorId.HasValue && !await db.Majors.AnyAsync(x => x.Id == request.MajorId && (!collegeId.HasValue || x.CollegeId == collegeId), token))
             return ValidationProblem("适用专业不在当前维护范围内。");
+        if (await HasSameScopeRuleAsync(request, id, token))
+            return ConflictProblem();
         rule.MajorId = request.MajorId; rule.EffectiveGrade = request.EffectiveGrade; rule.IsEnabled = request.IsEnabled; rule.Notes = request.Notes?.Trim();
         await db.SaveChangesAsync(token);
         return NoContent();
     }
 
+    [HttpDelete("{id:guid}")]
+    public async Task<ActionResult> Delete(Guid id, CancellationToken token)
+    {
+        var rule = await Scoped(scope.Current.RestrictedCollegeId)
+            .FirstOrDefaultAsync(x => x.Id == id, token);
+        if (rule is null) return NotFound();
+        if (await db.CourseSubstitutions.AnyAsync(
+                x => x.CourseEquivalencyRuleId == id, token))
+            return Conflict(new ProblemDetails
+            {
+                Title = "该规则已有课程替代申请引用，不能删除；请改为停用以保留审批和毕业审核留痕。",
+                Status = StatusCodes.Status409Conflict
+            });
+        db.CourseEquivalencyRules.Remove(rule);
+        await db.SaveChangesAsync(token);
+        return NoContent();
+    }
+
+    private Task<bool> HasSameScopeRuleAsync(
+        CourseEquivalencyRuleRequest request,
+        Guid? exceptId,
+        CancellationToken token) => db.CourseEquivalencyRules.AnyAsync(x =>
+            x.OriginalCourseId == request.OriginalCourseId &&
+            x.SubstituteCourseId == request.SubstituteCourseId &&
+            x.MajorId == request.MajorId &&
+            x.EffectiveGrade == request.EffectiveGrade &&
+            (!exceptId.HasValue || x.Id != exceptId.Value), token);
+
+    private static ConflictObjectResult ConflictProblem() =>
+        new(new ProblemDetails
+        {
+            Title = "相同适用范围的等价课程规则已存在。",
+            Status = StatusCodes.Status409Conflict
+        });
+
     private IQueryable<CourseEquivalencyRule> Scoped(Guid? collegeId) => collegeId.HasValue
         ? db.CourseEquivalencyRules.Where(x => x.OriginalCourse!.CollegeId == collegeId.Value)
         : db.CourseEquivalencyRules;

web/src/views/CourseEquivalencyRulesView.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { onMounted, reactive, ref } from 'vue'
-import { ElMessage } from 'element-plus'
+import { ElMessage, ElMessageBox } from 'element-plus'
 import http, { apiErrorMessage } from '../api/http'
 
 const rows = ref<any[]>([])
@@ -37,6 +37,21 @@ async function toggle(row: any) {
     await load()
   } catch (error) { ElMessage.error(apiErrorMessage(error)) }
 }
+
+async function remove(row: any) {
+  try {
+    await ElMessageBox.confirm(
+      `确认删除“${row.substituteCourseName} → ${row.originalCourseName}”规则吗？未被申请引用的规则才可删除。`,
+      '删除等价课程规则',
+      { type: 'warning', confirmButtonText: '删除', cancelButtonText: '取消' },
+    )
+    await http.delete(`/course-equivalency-rules/${row.id}`)
+    ElMessage.success('规则已删除')
+    await load()
+  } catch (error: any) {
+    if (error !== 'cancel' && error !== 'close') ElMessage.error(apiErrorMessage(error))
+  }
+}
 onMounted(load)
 </script>
 
@@ -44,6 +59,6 @@ onMounted(load)
   <div class="page-stack" v-loading="loading">
     <section class="page-intro"><div><span class="section-kicker">EQUIVALENCY RULES</span><h2>等价课程规则</h2><p>先维护可追溯的等价关系；学生只能按适用规则申请课程替代。</p></div></section>
     <el-card><el-form :inline="true" @submit.prevent="create"><el-form-item label="被替代课程"><el-select v-model="form.originalCourseId" filterable placeholder="选择课程" style="width:240px"><el-option v-for="course in courses" :key="course.id" :label="`${course.code} · ${course.name}`" :value="course.id" /></el-select></el-form-item><el-form-item label="等价课程"><el-select v-model="form.substituteCourseId" filterable placeholder="选择课程" style="width:240px"><el-option v-for="course in courses" :key="course.id" :label="`${course.code} · ${course.name}`" :value="course.id" /></el-select></el-form-item><el-form-item label="适用年级"><el-input-number v-model="form.effectiveGrade" :min="2000" :max="2100" controls-position="right" placeholder="全部" /></el-form-item><el-form-item label="说明"><el-input v-model="form.notes" maxlength="500" /></el-form-item><el-button type="primary" native-type="submit">建立规则</el-button></el-form></el-card>
-    <el-table :data="rows" stripe><el-table-column label="等价关系" min-width="300"><template #default="{ row }">{{ row.substituteCourseCode }} {{ row.substituteCourseName }} → {{ row.originalCourseCode }} {{ row.originalCourseName }}</template></el-table-column><el-table-column label="适用范围" min-width="160"><template #default="{ row }">{{ row.majorName || '全部专业' }} · {{ row.effectiveGrade || '全部年级' }}</template></el-table-column><el-table-column prop="notes" label="说明" min-width="180" /><el-table-column label="状态" width="130"><template #default="{ row }"><el-switch :model-value="row.isEnabled" active-text="启用" inactive-text="停用" @change="toggle(row)" /></template></el-table-column></el-table>
+    <el-table :data="rows" stripe><el-table-column label="等价关系" min-width="300"><template #default="{ row }">{{ row.substituteCourseCode }} {{ row.substituteCourseName }} → {{ row.originalCourseCode }} {{ row.originalCourseName }}</template></el-table-column><el-table-column label="适用范围" min-width="160"><template #default="{ row }">{{ row.majorName || '全部专业' }} · {{ row.effectiveGrade || '全部年级' }}</template></el-table-column><el-table-column prop="notes" label="说明" min-width="180" /><el-table-column label="状态" width="130"><template #default="{ row }"><el-switch :model-value="row.isEnabled" active-text="启用" inactive-text="停用" @change="toggle(row)" /></template></el-table-column><el-table-column label="操作" width="85" fixed="right"><template #default="{ row }"><el-button link type="danger" @click="remove(row)">删除</el-button></template></el-table-column></el-table>
   </div>
 </template>