feat(api): add GitHub oauth

.env.example

@@ -2,6 +2,11 @@ DATABASE_URL=postgresql://postgres:<your-project-password>@db.<your-project-name
 SUPABASE_API_URL=https://<your-project-name>.supabase.co
 SUPABASE_ANON_KEY=
 
+GITHUB_CLIENT_ID= 
+GITHUB_CLIENT_SECRET= 
+GITHUB_CALLBACK_URL=
+
+
 SMTP_HOST=
 SMTP_PORT=
 SMTP_EMAIL_ADDRESS=

apps/api/src/auth/auth.module.ts

@@ -3,6 +3,7 @@ import { AuthService } from './service/auth.service'
 import { AuthController } from './controller/auth.controller'
 import { JwtModule } from '@nestjs/jwt'
 import { UserModule } from '../user/user.module'
+import { GithubStrategy } from './github.stratergy'
 
 @Module({
   imports: [
@@ -17,7 +18,7 @@ import { UserModule } from '../user/user.module'
     }),
     UserModule
   ],
-  providers: [AuthService],
+  providers: [AuthService, GithubStrategy],
   controllers: [AuthController]
 })
 export class AuthModule {}

apps/api/src/auth/controller/auth.controller.ts

@@ -1,8 +1,18 @@
-import { Controller, HttpStatus, Param, Post, Query } from '@nestjs/common'
+import {
+  Controller,
+  Get,
+  HttpStatus,
+  Param,
+  Post,
+  Query,
+  Req,
+  UseGuards
+} from '@nestjs/common'
 import { AuthService } from '../service/auth.service'
 import { UserAuthenticatedResponse } from '../auth.types'
 import { Public } from '../../decorators/public.decorator'
 import { ApiOperation, ApiParam, ApiResponse, ApiTags } from '@nestjs/swagger'
+import { AuthGuard } from '@nestjs/passport'
 
 @ApiTags('Auth Controller')
 @Controller('auth')
@@ -71,4 +81,49 @@ export class AuthController {
   ): Promise<UserAuthenticatedResponse> {
     return await this.authService.validateOtp(email, otp)
   }
+
+  @Public()
+  @Get('github')
+  @UseGuards(AuthGuard('github'))
+  @ApiOperation({
+    summary: 'Github OAuth',
+    description:
+      'This endpoint validates Github OAuth. If the OAuth is valid, it returns a valid token along with the user details'
+  })
+  async githubOAuthLogin() {
+    /**
+     * NOTE:
+     * This function does nothing and the oauth redirect is managed my AuthGuard
+     * - The 'github' method inside the authguard is managed by passport
+     */
+  }
+
+  @Public()
+  @Get('github/callback')
+  @UseGuards(AuthGuard('github'))
+  @ApiOperation({
+    summary: 'Github OAuth Callback',
+    description:
+      'This endpoint validates Github OAuth. If the OAuth is valid, it returns a valid token along with the user details'
+  })
+  @ApiParam({
+    name: 'code',
+    description: 'Code for the Callback',
+    required: true
+  })
+  @ApiResponse({
+    status: HttpStatus.OK,
+    description: 'Logged in successfully'
+  })
+  // TODO: Change the Res Code from 500 -> 401, when incorrect code is provided
+  async githubOAuthCallback(@Req() req) {
+    const { emails, displayName: name, photos } = req.user
+    const email = emails[0].value
+    const profilePictureUrl = photos[0].value
+    return await this.authService.handleGithubOAuth(
+      email,
+      name,
+      profilePictureUrl
+    )
+  }
 }

apps/api/src/auth/github.stratergy.ts

@@ -0,0 +1,20 @@
+import { Injectable } from '@nestjs/common'
+import { ConfigService } from '@nestjs/config'
+import { PassportStrategy } from '@nestjs/passport'
+import { Profile, Strategy } from 'passport-github2'
+
+@Injectable()
+export class GithubStrategy extends PassportStrategy(Strategy, 'github') {
+  constructor(configService: ConfigService) {
+    super({
+      clientID: configService.get<string>('GITHUB_CLIENT_ID'),
+      clientSecret: configService.get<string>('GITHUB_CLIENT_SECRET'),
+      callbackURL: configService.get<string>('GITHUB_CALLBACK_URL'),
+      scope: ['public_profile', 'user:email']
+    })
+  }
+
+  async validate(accessToken: string, _refreshToken: string, profile: Profile) {
+    return profile
+  }
+}

apps/api/src/auth/service/auth.service.ts

@@ -29,21 +29,21 @@ export class AuthService {
     this.logger = new Logger(AuthService.name)
   }
 
-  async sendOtp(email: string): Promise<void> {
-    if (!email || !email.includes('@')) {
-      this.logger.error(`Invalid email address: ${email}`)
-      throw new HttpException(
-        'Please enter a valid email address',
-        HttpStatus.BAD_REQUEST
-      )
-    }
+  private async createUserIfNotExists(
+    email: string,
+    name?: string,
+    profilePictureUrl?: string
+  ) {
+    let user = await this.findUserByEmail(email)
 
     // We need to create the user if it doesn't exist yet
-    if (!(await this.findUserByEmail(email))) {
+    if (!user) {
       // Create the user
-      const user = await this.prisma.user.create({
+      user = await this.prisma.user.create({
         data: {
-          email
+          email,
+          name,
+          profilePictureUrl
         }
       })
 
@@ -62,7 +62,18 @@ export class AuthService {
         }
       })
     }
+    return user
+  }
 
+  async sendOtp(email: string): Promise<void> {
+    if (!email || !email.includes('@')) {
+      this.logger.error(`Invalid email address: ${email}`)
+      throw new HttpException(
+        'Please enter a valid email address',
+        HttpStatus.BAD_REQUEST
+      )
+    }
+    await this.createUserIfNotExists(email)
     const otp = await this.prisma.otp.create({
       data: {
         code: randomUUID().slice(0, 6).toUpperCase(),
@@ -126,6 +137,24 @@ export class AuthService {
     }
   }
 
+  async handleGithubOAuth(
+    email: string,
+    name: string,
+    profilePictureUrl: string
+  ) {
+    // We need to create the user if it doesn't exist yet
+    const user = await this.createUserIfNotExists(
+      email,
+      name,
+      profilePictureUrl
+    )
+
+    return {
+      ...user,
+      token: await this.jwt.signAsync({ id: user.id })
+    }
+  }
+
   @Cron(CronExpression.EVERY_HOUR)
   async cleanUpExpiredOtps() {
     try {

package.json

@@ -113,6 +113,8 @@
     "moment": "^2.30.1",
     "next": "14.0.4",
     "nodemailer": "^6.9.8",
+    "passport": "^0.7.0",
+    "passport-github2": "^0.1.12",
     "passport-jwt": "^4.0.1",
     "react": "18.2.0",
     "react-dom": "18.2.0",