creates application

backend/src/middleware/auth.ts

@@ -0,0 +1,43 @@
+import { Request, Response, NextFunction } from 'express';
+import { prisma } from '../prisma/client';
+import type { AuthenticatedRequest, AuthenticatedUser } from '../types';
+
+export function requireAuth(
+  req: AuthenticatedRequest,
+  res: Response,
+  next: NextFunction
+): void {
+  if (!req.session?.user) {
+    res.status(401).json({ error: 'Unauthorized' });
+    return;
+  }
+  
+  req.user = req.session.user as AuthenticatedUser;
+  next();
+}
+
+export function optionalAuth(
+  req: AuthenticatedRequest,
+  res: Response,
+  next: NextFunction
+): void {
+  if (req.session?.user) {
+    req.user = req.session.user as AuthenticatedUser;
+  }
+  next();
+}
+
+export async function syncUser(user: AuthenticatedUser): Promise<void> {
+  await prisma.user.upsert({
+    where: { id: user.id },
+    update: {
+      username: user.username,
+      email: user.email,
+    },
+    create: {
+      id: user.id,
+      username: user.username,
+      email: user.email,
+    },
+  });
+}

backend/src/middleware/errorHandler.ts

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+import { Request, Response, NextFunction } from 'express';
+import { Prisma } from '@prisma/client';
+
+export interface ApiError extends Error {
+  statusCode?: number;
+  code?: string;
+}
+
+export function errorHandler(
+  err: ApiError,
+  _req: Request,
+  res: Response,
+  _next: NextFunction
+): void {
+  console.error('Error:', err);
+  
+  // Prisma errors
+  if (err instanceof Prisma.PrismaClientKnownRequestError) {
+    switch (err.code) {
+      case 'P2002':
+        res.status(409).json({ error: 'Resource already exists' });
+        return;
+      case 'P2025':
+        res.status(404).json({ error: 'Resource not found' });
+        return;
+      case 'P2003':
+        res.status(400).json({ error: 'Invalid reference to related resource' });
+        return;
+      default:
+        res.status(500).json({ error: 'Database error' });
+        return;
+    }
+  }
+  
+  if (err instanceof Prisma.PrismaClientValidationError) {
+    res.status(400).json({ error: 'Invalid data format' });
+    return;
+  }
+  
+  const statusCode = err.statusCode || 500;
+  const message = err.message || 'Internal server error';
+  
+  res.status(statusCode).json({ 
+    error: statusCode === 500 ? 'Internal server error' : message 
+  });
+}
+
+export function notFoundHandler(
+  _req: Request,
+  res: Response,
+  _next: NextFunction
+): void {
+  res.status(404).json({ error: 'Endpoint not found' });
+}

backend/src/middleware/validation.ts

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+import { Request, Response, NextFunction } from 'express';
+import { ZodSchema, ZodError } from 'zod';
+
+export function validateBody<T>(schema: ZodSchema<T>) {
+  return (req: Request, res: Response, next: NextFunction): void => {
+    try {
+      req.body = schema.parse(req.body);
+      next();
+    } catch (error) {
+      if (error instanceof ZodError) {
+        const errors = error.errors.map(e => ({
+          path: e.path.join('.'),
+          message: e.message,
+        }));
+        res.status(400).json({ error: 'Validation failed', details: errors });
+        return;
+      }
+      next(error);
+    }
+  };
+}
+
+export function validateParams<T>(schema: ZodSchema<T>) {
+  return (req: Request, res: Response, next: NextFunction): void => {
+    try {
+      req.params = schema.parse(req.params) as typeof req.params;
+      next();
+    } catch (error) {
+      if (error instanceof ZodError) {
+        res.status(400).json({ error: 'Invalid parameters', details: error.errors });
+        return;
+      }
+      next(error);
+    }
+  };
+}
+
+export function validateQuery<T>(schema: ZodSchema<T>) {
+  return (req: Request, res: Response, next: NextFunction): void => {
+    try {
+      req.query = schema.parse(req.query) as typeof req.query;
+      next();
+    } catch (error) {
+      if (error instanceof ZodError) {
+        res.status(400).json({ error: 'Invalid query parameters', details: error.errors });
+        return;
+      }
+      next(error);
+    }
+  };
+}