custom URL short code

backend/src/app.controller.ts

@@ -3,10 +3,12 @@ import {AppService} from './app.service';
 import {UrlShortenDTO} from "./dto/url.shorten";
 import isURL from 'validator/lib/isURL';
 import {Response} from "express";
+import * as process from "node:process";
 
 @Controller()
 export class AppController {
   private logger = new Logger("AppController");
+
   constructor(private readonly appService: AppService) {
   }
 
@@ -30,8 +32,12 @@ export class AppController {
     if (!this.isValidURL(urlShortenDTO.url)) {
       throw new HttpException("Invalid URL", HttpStatus.BAD_REQUEST);
     }
+    if (urlShortenDTO.customUrlCode && urlShortenDTO.customUrlCode.length != 12) {
+      throw new HttpException("Custom URL code too long", HttpStatus.BAD_REQUEST);
+    }
     try {
-      return await this.appService.postURLShorten(urlShortenDTO.url);
+      const shortUrlCode = await this.appService.postURLShorten(urlShortenDTO.url, urlShortenDTO.customUrlCode);
+      return (process.env.APP_URL || 'http://localhost:3000/') + shortUrlCode;
     } catch (e) {
       throw new HttpException({
         status: HttpStatus.INTERNAL_SERVER_ERROR,

backend/src/app.service.ts

@@ -1,4 +1,4 @@
-import {Inject, Injectable, OnModuleDestroy} from "@nestjs/common";
+import {HttpException, HttpStatus, Inject, Injectable, OnModuleDestroy} from "@nestjs/common";
 import {Redis} from "ioredis";
 @Injectable()
 export class AppService implements OnModuleDestroy{
@@ -12,13 +12,23 @@ export class AppService implements OnModuleDestroy{
     return this.redis.ping();
   }
 
-  async postURLShorten(url: string): Promise<string> {
+  async postURLShorten(url: string, customUrlCode:string): Promise<string> {
     const shortURLFromRedis = await this.redis.get(url);
     if(shortURLFromRedis) {
       return shortURLFromRedis;
     }
-    const { nanoid } = await import('nanoid');
-    const shortURL = nanoid(12);
+    let shortURL:string;
+    if (customUrlCode) {
+      const existingURL = await this.redis.get(customUrlCode);
+      if(existingURL) {
+        throw new HttpException("Custom URL already exists",HttpStatus.CONFLICT);
+      }
+      shortURL = customUrlCode;
+    }else {
+      const { nanoid } = await import('nanoid');
+      shortURL = nanoid(12);
+    }
+
     return new Promise((resolve, reject) => {
       this.redis.multi()
         .set(shortURL, url)

backend/src/dto/url.shorten.ts

@@ -1,3 +1,18 @@
+import {ApiProperty} from "@nestjs/swagger";
+
 export class UrlShortenDTO {
+  @ApiProperty({
+    example: "https://www2.gov.bc.ca/gov/content/environment",
+    description: "The URL for which short URL is to be generated",
+    required: true,
+    format: "url",
+  })
   url: string;
+  @ApiProperty({
+    example: "W0jsiQdywoj",
+    description: "Random 12 character string, if not provided, system will generate it.",
+    maxLength: 12,
+    minLength: 12,
+  })
+  customUrlCode?: string;
 }

charts/app/templates/backend/templates/deployment.yaml

@@ -41,6 +41,8 @@ spec:
               value: info
             - name: REDIS_HOST
               value: {{.Release.Name}}-redis
+            - name: APP_URL
+              value: https://{{ .Release.Name }}-backend.apps.silver.devops.gov.bc.ca/
           ports:
             - name: http
               containerPort: {{ .Values.backend.service.targetPort }}