feat(admin): add competition cancellation endpoint with refunds

backend/src/admin/admin.controller.spec.ts

@@ -0,0 +1,48 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { AdminController } from './admin.controller';
+import { AdminService } from './admin.service';
+
+describe('AdminController', () => {
+  let controller: AdminController;
+  let service: {
+    adminCancelCompetition: jest.Mock;
+  };
+
+  beforeEach(async () => {
+    service = {
+      adminCancelCompetition: jest.fn(),
+    };
+
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [AdminController],
+      providers: [
+        {
+          provide: AdminService,
+          useValue: service,
+        },
+      ],
+    }).compile();
+
+    controller = module.get<AdminController>(AdminController);
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+
+  describe('cancelCompetition', () => {
+    it('calls admin service with competition id and admin id', async () => {
+      const result = { id: 'comp-1', is_cancelled: true };
+      service.adminCancelCompetition.mockResolvedValue(result);
+
+      const req = { user: { id: 'admin-1' } };
+      const response = await controller.cancelCompetition('comp-1', req);
+
+      expect(service.adminCancelCompetition).toHaveBeenCalledWith(
+        'comp-1',
+        'admin-1',
+      );
+      expect(response).toEqual(result);
+    });
+  });
+});

backend/src/admin/admin.controller.ts

@@ -2,17 +2,19 @@ import {
   Body,
   Controller,
   Get,
-  Param,
+  Delete,
   Patch,
+  Param,
   Post,
   Query,
   Request,
   UseGuards,
 } from '@nestjs/common';
-import { Roles } from '../common/decorators/roles.decorator';
-import { Role } from '../common/enums/role.enum';
+import { ApiBearerAuth, ApiOperation, ApiResponse } from '@nestjs/swagger';
 import { JwtAuthGuard } from '../common/guards/jwt-auth.guard';
 import { RolesGuard } from '../common/guards/roles.guard';
+import { Roles } from '../common/decorators/roles.decorator';
+import { Role } from '../common/enums/role.enum';
 import { AdminService } from './admin.service';
 import { ActivityLogQueryDto } from './dto/activity-log-query.dto';
 import { BanUserDto } from './dto/ban-user.dto';
@@ -34,6 +36,23 @@ export class AdminController {
     return this.adminService.getStats();
   }
 
+  @Delete('competitions/:id')
+  @ApiBearerAuth()
+  @ApiOperation({ summary: 'Cancel a competition' })
+  @ApiResponse({ status: 200, description: 'Competition cancelled' })
+  @ApiResponse({ status: 404, description: 'Competition not found' })
+  @ApiResponse({
+    status: 409,
+    description: 'Competition cannot be cancelled',
+  })
+  @ApiResponse({ status: 502, description: 'Refund process failed' })
+  async cancelCompetition(@Param('id') id: string, @Request() req: any) {
+    return this.adminService.adminCancelCompetition(
+      id,
+      (req as { user: { id: string } }).user.id,
+    );
+  }
+
   @Get('users')
   async listUsers(@Query() query: ListUsersQueryDto) {
     return this.adminService.listUsers(query);

backend/src/admin/admin.module.ts

@@ -5,6 +5,7 @@ import { Market } from '../markets/entities/market.entity';
 import { Comment } from '../markets/entities/comment.entity';
 import { Prediction } from '../predictions/entities/prediction.entity';
 import { Competition } from '../competitions/entities/competition.entity';
+import { CompetitionParticipant } from '../competitions/entities/competition-participant.entity';
 import { ActivityLog } from '../analytics/entities/activity-log.entity';
 import { NotificationsModule } from '../notifications/notifications.module';
 import { AdminController } from './admin.controller';
@@ -18,6 +19,7 @@ import { AdminService } from './admin.service';
       Comment,
       Prediction,
       Competition,
+      CompetitionParticipant,
       ActivityLog,
     ]),
     NotificationsModule,