add invite code support

src/app.module.ts

@@ -3,9 +3,7 @@ import { AppController } from './app.controller';
 import { AppService } from './app.service';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { ConfigModule, ConfigService } from '@nestjs/config';
-import { VoteController } from './vote/vote.controller';
-import { VoteService } from './vote/vote.service';
-import { Answer, Vote } from './vote/vote.entity';
+import { Answer, InviteCode, Vote } from './vote/vote.entity';
 import { VoteModule } from './vote/vote.module';
 
 void ConfigModule.forRoot({
@@ -24,7 +22,7 @@ const configService = new ConfigService();
       username: configService.get('PG_USER'),
       database: configService.get('PG_DATABASE'),
       synchronize: configService.get('DEV_MODE') == 'true',
-      entities: [Vote, Answer],
+      entities: [Vote, Answer, InviteCode],
     }),
     VoteModule,
   ],

src/vote/vote.controller.ts

@@ -1,4 +1,13 @@
-import { Body, Controller, Get, Param, Post } from '@nestjs/common';
+import {
+  Body,
+  Controller,
+  Get,
+  HttpException,
+  HttpStatus,
+  Param,
+  ParseUUIDPipe,
+  Post,
+} from '@nestjs/common';
 import { VoteCreateDTO } from './vote.dto';
 import { VoteService } from './vote.service';
 import { ApiOperation } from '@nestjs/swagger';
@@ -7,18 +16,38 @@ import { ApiOperation } from '@nestjs/swagger';
 export class VoteController {
   constructor(private readonly voteService: VoteService) {}
 
+  @Get('check/:accessCode')
+  @ApiOperation({ summary: 'Checks if a code has been used' })
+  async check(@Param('accessCode', new ParseUUIDPipe()) accessCode: string) {
+    const value = await this.voteService.check(accessCode);
+    if (value === null) {
+      throw new HttpException('Invalid accessCode', HttpStatus.NOT_FOUND);
+    }
+    if (value === false) {
+      throw new HttpException('AccessCode expired', HttpStatus.FORBIDDEN);
+    }
+    return;
+  }
+
   @Post('vote/:accessCode')
   @ApiOperation({ summary: 'Vote for a poll' })
   async vote(
-    @Param('accessCode') accessCode: string,
+    @Param('accessCode', new ParseUUIDPipe()) accessCode: string,
     @Body() answer: VoteCreateDTO,
   ) {
-    await this.voteService.create(answer);
+    const code = await this.voteService.check(accessCode);
+    if (code === null) {
+      throw new HttpException('Invalid accessCode', HttpStatus.NOT_FOUND);
+    }
+    if (code === false) {
+      throw new HttpException('AccessCode expired', HttpStatus.FORBIDDEN);
+    }
+    await this.voteService.create(answer, code);
   }
 
   @Get('results/:accessCode')
   @ApiOperation({ summary: 'Get results' })
-  async results(@Param('accessCode') accessCode: string) {
+  async results(@Param('accessCode', new ParseUUIDPipe()) accessCode: string) {
     return await this.voteService.getResults();
   }
 }

src/vote/vote.entity.ts

@@ -4,6 +4,8 @@ import {
   OneToMany,
   ManyToOne,
   Column,
+  OneToOne,
+  Generated,
 } from 'typeorm';
 
 @Entity()
@@ -16,6 +18,13 @@ export class Vote {
     eager: true,
   })
   answers: Answer[];
+
+  @OneToOne(() => InviteCode, (code) => code.vote, {
+    eager: false,
+    onDelete: 'CASCADE',
+    nullable: false,
+  })
+  code: Promise<InviteCode>;
 }
 
 @Entity()
@@ -35,3 +44,22 @@ export class Answer {
   @Column()
   answer: string;
 }
+
+@Entity()
+export class InviteCode {
+  @PrimaryGeneratedColumn({})
+  id: number;
+
+  @OneToOne(() => Vote, (vote) => vote.code, {
+    eager: false,
+    onDelete: 'CASCADE',
+  })
+  vote: Promise<Vote>;
+
+  @Column({ default: 1 })
+  usages_left: number;
+
+  @Column()
+  @Generated('uuid')
+  value: string;
+}

src/vote/vote.module.ts

@@ -1,11 +1,11 @@
 import { Module } from '@nestjs/common';
-import { Answer, Vote } from './vote.entity';
+import { InviteCode, Vote } from './vote.entity';
 import { VoteController } from './vote.controller';
 import { VoteService } from './vote.service';
 import { TypeOrmModule } from '@nestjs/typeorm';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([Vote, Answer])],
+  imports: [TypeOrmModule.forFeature([Vote, InviteCode])],
   controllers: [VoteController],
   providers: [VoteService],
 })

src/vote/vote.service.ts

@@ -1,6 +1,6 @@
 import { Injectable } from '@nestjs/common';
 import { VoteCreateDTO } from './vote.dto';
-import { Vote } from './vote.entity';
+import { InviteCode, Vote } from './vote.entity';
 import { Repository } from 'typeorm';
 import { InjectRepository } from '@nestjs/typeorm';
 
@@ -17,8 +17,13 @@ interface IVote {
 export class VoteService {
   constructor(
     @InjectRepository(Vote) private voteRepository: Repository<Vote>,
+    @InjectRepository(InviteCode)
+    private inviteCodeRepository: Repository<InviteCode>,
   ) {}
-  async create(value: VoteCreateDTO) {
+  async create(value: VoteCreateDTO, accessCode: InviteCode) {
+    accessCode.usages_left--;
+    await this.inviteCodeRepository.save(accessCode);
+
     const vote = Object.entries(value).reduce<IVote>(
       (acc, [question_id, a]) => {
         const answer = String(a);
@@ -51,4 +56,17 @@ export class VoteService {
     }
     return compiled_results;
   }
+
+  async check(inviteCode: string) {
+    const code = await this.inviteCodeRepository.findOneBy({
+      value: inviteCode,
+    });
+    if (!code) {
+      return null;
+    }
+    if (code.usages_left > 0) {
+      return code;
+    }
+    return false;
+  }
 }