add middleware info

src/app.controller.ts

 import { Body, Controller, Get, Post, ValidationPipe } from '@nestjs/common';
 import { AppService } from './app.service';
-import { ApiBody, ApiCreatedResponse, ApiOperation } from '@nestjs/swagger';
+import {
+  ApiBody,
+  ApiCreatedResponse,
+  ApiOkResponse,
+  ApiOperation,
+} from '@nestjs/swagger';
 import { PostUrlDto } from './dto/PostUrl.dto';
-import { StringReturnMessageDto } from './dto/ReturnMessage.dto';
+import {
+  MiddlewareInfoReturnMessageDto,
+  StringReturnMessageDto,
+} from './dto/ReturnMessage.dto';
 
 @Controller()
 export class AppController {
   constructor(private readonly appService: AppService) {}
 
+  @Get('jsd')
+  @ApiOperation({ summary: 'JSDelivr', description: '需要配置 JSD_URL' })
+  @ApiOkResponse({ type: MiddlewareInfoReturnMessageDto })
+  jsdInfo() {
+    return this.appService.jsdInfo();
+  }
+
   @Post('jsd')
   @ApiOperation({ summary: 'JSDelivr', description: '需要配置 JSD_URL' })
   @ApiBody({ type: PostUrlDto })

src/app.service.ts

@@ -11,13 +11,16 @@ import {
 import FormData from 'form-data';
 import { PostUrlDto } from './dto/PostUrl.dto';
 import hasha from 'hasha';
+import { MiddlewareInfoDto } from './dto/MiddlewareInfo.dto';
 
 @Injectable()
 export class AppService extends ConsoleLogger {
   private jsdUrl: string;
+  private jsdIdentifier: string;
   constructor(config: ConfigService, private http: HttpService) {
     super('app');
     this.jsdUrl = config.get('JSD_URL');
+    this.jsdIdentifier = config.get('JSD_IDENTIFIER') || `jsd-${this.jsdUrl}`;
   }
 
   private async getStreamFromUrl(url: string) {
@@ -34,6 +37,16 @@ export class AppService extends ConsoleLogger {
     }
   }
 
+  jsdInfo() {
+    if (!this.jsdUrl) {
+      throw new BlankReturnMessageDto(404, 'JSDelivr is not configured.');
+    }
+    const info = new MiddlewareInfoDto();
+    info.identifier = this.jsdIdentifier;
+    info.maxSize = 50 * 1024 * 1024;
+    return new ReturnMessageDto(200, 'success', info);
+  }
+
   async jsd(urlDto: PostUrlDto) {
     if (!this.jsdUrl) {
       throw new BlankReturnMessageDto(404, 'JSDelivr is not configured.');

src/dto/MiddlewareInfo.dto.ts

+import { ApiProperty } from '@nestjs/swagger';
+
+export class MiddlewareInfoDto {
+  @ApiProperty({ description: '标识符' })
+  identifier: string;
+  @ApiProperty({ description: '最大文件大小' })
+  maxSize?: number;
+}

src/dto/ReturnMessage.dto.ts

 import { ApiProperty } from '@nestjs/swagger';
 import { HttpException } from '@nestjs/common';
+import { MiddlewareInfoDto } from './MiddlewareInfo.dto';
 
 export interface BlankReturnMessage {
   statusCode: number;
@@ -44,3 +45,8 @@ export class StringReturnMessageDto extends BlankReturnMessageDto {
   @ApiProperty({ description: '返回内容' })
   data: string;
 }
+
+export class MiddlewareInfoReturnMessageDto extends BlankReturnMessageDto {
+  @ApiProperty({ description: '返回内容' })
+  data: MiddlewareInfoDto;
+}