feat: implement OAuth2 Google and Apple authentication (#142)

backend/package.json

@@ -52,6 +52,8 @@
     "@stellar/stellar-sdk": "^14.4.3",
     "@types/fluent-ffmpeg": "^2.1.28",
     "@types/multer": "^2.0.0",
+    "@types/passport-google-oauth20": "^2.0.17",
+    "apple-signin-auth": "^2.0.0",
     "bcrypt": "^6.0.0",
     "bullmq": "^5.66.6",
     "cache-manager": "^7.2.8",
@@ -65,6 +67,8 @@
     "kubo-rpc-client": "^6.1.0",
     "multer": "^2.0.2",
     "passport": "^0.7.0",
+    "passport-apple": "^2.0.2",
+    "passport-google-oauth20": "^2.0.0",
     "passport-jwt": "^4.0.1",
     "pg": "^8.17.1",
     "qrcode": "^1.5.3",

backend/src/auth/auth.controller.ts

@@ -6,9 +6,11 @@ import {
   HttpStatus,
   UseGuards,
   Req,
+  Get,
 } from '@nestjs/common';
 import type { Request } from 'express';
 import { Throttle } from '@nestjs/throttler';
+import { AuthGuard } from '@nestjs/passport';
 import { AuthService } from './auth.service';
 import {
   RegisterDto,
@@ -104,4 +106,44 @@ export class AuthController {
     await this.authService.resetPassword(resetPasswordDto);
     return { message: 'Password reset successfully' };
   }
+
+  // --- Google OAuth2 ---
+
+  @Get('google')
+  @UseGuards(AuthGuard('google'))
+  async googleAuth() {
+    // Initiates Google OAuth2 flow — handled by Passport
+  }
+
+  @Get('google/callback')
+  @UseGuards(AuthGuard('google'))
+  @HttpCode(HttpStatus.OK)
+  async googleAuthCallback(@Req() req: Request) {
+    const user = req.user as any;
+    return {
+      accessToken: user.accessToken,
+      refreshToken: user.refreshToken,
+      user: user.user,
+    };
+  }
+
+  // --- Apple Sign In ---
+
+  @Get('apple')
+  @UseGuards(AuthGuard('apple'))
+  async appleAuth() {
+    // Initiates Apple Sign In flow — handled by Passport
+  }
+
+  @Post('apple/callback')
+  @UseGuards(AuthGuard('apple'))
+  @HttpCode(HttpStatus.OK)
+  async appleAuthCallback(@Req() req: Request) {
+    const user = req.user as any;
+    return {
+      accessToken: user.accessToken,
+      refreshToken: user.refreshToken,
+      user: user.user,
+    };
+  }
 }