fIx: smaller nits

2026-03-20 00:04:46 +01:00
parent bc67d01bc2
commit c3cbe35883
21 changed files with 2093 additions and 116 deletions
--- a/backend/src/index.js
+++ b/backend/src/index.js
@@ -1,101 +0,0 @@
-/**
- * Minimal Express API: /api/agent, /health.
- * No DB, no auth. CORS allowed for frontend. Production-ready env (PORT, CORS_ORIGIN).
- */
-
-const express = require('express')
-const cors = require('cors')
-
-const PORT = Number(process.env.PORT) || 8080
-const CORS_ORIGIN = process.env.CORS_ORIGIN || 'http://localhost:3000'
-
-const app = express()
-
-app.use(cors({ origin: CORS_ORIGIN }))
-app.use(express.json())
-
-/** Build OpenAI client and full prompt from request body. Returns { openai, modelId, fullPrompt } or { error }. */
-function buildAgentRequest(body) {
-  const { prompt, context, contextNodes, connection: conn, reasoning } = body ?? {}
-  const reasoningEnabled = Boolean(reasoning)
-  let baseURL = process.env.AI_BASE_URL?.trim() || null
-  let apiKey = process.env.OPENAI_API_KEY?.trim() || null
-  let modelId = process.env.AI_MODEL?.trim() || (baseURL ? 'local-model' : 'gpt-4o-mini')
-  if (conn && typeof conn === 'object') {
-    const c = conn
-    const provider = c.provider === 'openai' ? 'openai' : 'local'
-    if (provider === 'local') {
-      baseURL = (typeof c.baseURL === 'string' && c.baseURL.trim()) ? c.baseURL.trim() : baseURL
-      apiKey = (typeof c.apiKey === 'string' && c.apiKey.trim()) ? c.apiKey.trim() : (apiKey || 'lm-studio')
-    } else {
-      baseURL = null
-      apiKey = (typeof c.apiKey === 'string' && c.apiKey.trim()) ? c.apiKey.trim() : apiKey
-    }
-    if (typeof c.model === 'string' && c.model.trim()) modelId = c.model.trim()
-  }
-  if (!baseURL && !apiKey) {
-    return { error: 'No AI configured. Set connection in Settings (AI) or env: OPENAI_API_KEY or AI_BASE_URL.' }
-  }
-  const basePrompt = [
-    typeof prompt === 'string' ? prompt : 'No prompt provided.',
-    context && typeof context === 'string' ? `\n\nAdditional context:\n${context}` : '',
-    Array.isArray(contextNodes) && contextNodes.length > 0
-      ? `\n\nContext from connected nodes:\n${contextNodes.map((n) => (n.content != null ? n.content : `${n.id}: (no content)`)).join('\n\n')}`
-      : '',
-  ].join('')
-  const fullPrompt = reasoningEnabled
-    ? basePrompt + '\n\nRespond in exactly two markdown sections. First: "## Reasoning" with your step-by-step reasoning. Then: "## Output" with only the final answer. No preamble.'
-    : basePrompt + '\n\nRespond with structured markdown only. No preamble.'
-  const { createOpenAI } = require('@ai-sdk/openai')
-  const openai = createOpenAI({
-    apiKey: apiKey || 'lm-studio',
-    ...(baseURL && { baseURL, compatibility: 'compatible' }),
-  })
-  return { openai, modelId, fullPrompt }
-}
-
-/** POST /api/agent — run AI agent; body: { prompt, context?, contextNodes?, connection? }; returns { markdown }. */
-app.post('/api/agent', async (req, res) => {
-  try {
-    const built = buildAgentRequest(req.body)
-    if (built.error) return res.status(503).json({ error: built.error })
-    const { generateText } = await import('ai')
-    const result = await generateText({
-      model: built.openai(built.modelId),
-      prompt: built.fullPrompt,
-    })
-    const markdown = result?.text ?? ''
-    res.json({ markdown })
-  } catch (err) {
-    console.error('Agent error:', err)
-    res.status(500).json({ error: err?.message ?? 'Agent request failed' })
-  }
-})
-
-/** POST /api/agent/stream — same as /api/agent but streams plain text (markdown) chunks. */
-app.post('/api/agent/stream', async (req, res) => {
-  try {
-    const built = buildAgentRequest(req.body)
-    if (built.error) return res.status(503).json({ error: built.error })
-    const { streamText } = await import('ai')
-    const result = streamText({
-      model: built.openai(built.modelId),
-      prompt: built.fullPrompt,
-    })
-    res.setHeader('Content-Type', 'text/plain; charset=utf-8')
-    res.setHeader('Transfer-Encoding', 'chunked')
-    result.pipeTextStreamToResponse(res)
-  } catch (err) {
-    console.error('Agent stream error:', err)
-    res.status(500).json({ error: err?.message ?? 'Agent request failed' })
-  }
-})
-
-/** Health check for Docker / orchestration */
-app.get('/health', (req, res) => {
-  res.status(200).json({ ok: true })
-})
-
-app.listen(PORT, '0.0.0.0', () => {
-  console.log(`Backend listening on port ${PORT} (CORS: ${CORS_ORIGIN})`)
-})
--- a/backend/src/index.ts
+++ b/backend/src/index.ts
@@ -0,0 +1,102 @@
+/**
+ * Backend API: Layered architecture for scalability and maintainability.
+ * 
+ * ## Architecture Layers
+ * 
+ * ### Controllers (routes/)
+ * - Handle HTTP requests and responses
+ * - Validate input and format output
+ * - Call services for business logic
+ * 
+ * ### Services (services/)
+ * - Implement business logic
+ * - Coordinate between controllers and repositories
+ * - Handle validation and transformation
+ * 
+ * ### Repositories (repositories/)
+ * - Data access layer
+ * - Interact with databases or external APIs
+ * - Return domain models
+ * 
+ * ### Models (models/)
+ * - Data structures and types
+ * - Validation schemas
+ * 
+ * ### Middleware (middleware/)
+ * - Request validation
+ * - Authentication/authorization
+ * - Rate limiting
+ * - Error handling
+ * 
+ * ## Adding New Endpoints
+ * 
+ * 1. Define the model in `models/`
+ * 2. Implement repository logic in `repositories/`
+ * 3. Implement service logic in `services/`
+ * 4. Create controller in `routes/`
+ * 5. Register route in `index.ts`
+ */
+
+import express from 'express'
+import cors from 'cors'
+
+// ---------------------------------------------------------------------------
+// Configuration
+// ---------------------------------------------------------------------------
+
+const PORT = Number(process.env.PORT) || 8080
+const CORS_ORIGIN = process.env.CORS_ORIGIN || 'http://localhost:3000'
+
+// ---------------------------------------------------------------------------
+// Express App Setup
+// ---------------------------------------------------------------------------
+
+const app = express()
+
+app.use(cors({ origin: CORS_ORIGIN }))
+app.use(express.json())
+
+// ---------------------------------------------------------------------------
+// Agent Routes
+// ---------------------------------------------------------------------------
+
+import { handleAgentRequest, handleAgentStreamRequest } from './routes/agentRoutes.js'
+
+/** POST /api/agent - Run AI agent */
+app.post('/api/agent', handleAgentRequest)
+
+/** POST /api/agent/stream - Stream AI agent response */
+app.post('/api/agent/stream', handleAgentStreamRequest)
+
+// ---------------------------------------------------------------------------
+// Health Check Endpoint
+// ---------------------------------------------------------------------------
+
+/** GET /health - Health check for Docker / orchestration */
+app.get('/health', (req, res) => {
+  res.status(200).json({ ok: true, timestamp: Date.now() })
+})
+
+// ---------------------------------------------------------------------------
+// Error Handling Middleware
+// ---------------------------------------------------------------------------
+
+/** Global error handler for consistent error responses */
+app.use((err: Error, req: express.Request, res: express.Response, next: express.NextFunction) => {
+  console.error('Error:', err)
+  res.status(500).json({ error: err.message ?? 'Internal server error' })
+})
+
+// ---------------------------------------------------------------------------
+// Start Server
+// ---------------------------------------------------------------------------
+
+app.listen(PORT, '0.0.0.0', () => {
+  console.log(`Backend listening on port ${PORT} (CORS: ${CORS_ORIGIN})`)
+})
+
+// ---------------------------------------------------------------------------
+// Export for testing
+// ---------------------------------------------------------------------------
+
+export default app
--- a/backend/src/middleware/rateLimiter.ts
+++ b/backend/src/middleware/rateLimiter.ts
@@ -0,0 +1,88 @@
+/**
+ * Middleware: Rate limiting for API endpoints.
+ * 
+ * This module provides rate limiting middleware to protect the API
+ * from abuse and ensure fair usage.
+ */
+
+/**
+ * Rate limit configuration
+ */
+export type RateLimitConfig = {
+  /** Maximum number of requests allowed in the window */
+  max: number
+  /** Window size in milliseconds */
+  windowMs: number
+  /** Error message to return when rate limited */
+  message?: string
+}
+
+/**
+ * Default rate limit configuration
+ */
+export const DEFAULT_RATE_LIMIT_CONFIG: RateLimitConfig = {
+  max: 100,
+  windowMs: 60 * 1000, // 1 minute
+  message: 'Too many requests, please try again later.',
+}
+
+/**
+ * In-memory store for rate limiting
+ */
+const rateLimitStore = new Map<string, { count: number; resetTime: number }>()
+
+/**
+ * Rate limiting middleware
+ * 
+ * @param config - Rate limit configuration
+ * @returns Express middleware function
+ */
+export function rateLimit(config: RateLimitConfig = DEFAULT_RATE_LIMIT_CONFIG) {
+  return (req: { ip?: string; socket?: { remoteAddress?: string } }, res: { status: (code: number) => { json: (body: { error: string }) => void }, locals: Record<string, unknown> }, next: () => void): void => {
+    const ip = req.ip || req.socket?.remoteAddress || 'unknown'
+    const now = Date.now()
+    
+    let entry = rateLimitStore.get(ip)
+    
+    if (!entry || now > entry.resetTime) {
+      // Reset the counter for a new window
+      entry = { count: 1, resetTime: now + config.windowMs }
+      rateLimitStore.set(ip, entry)
+      next()
+      return
+    }
+    
+    entry.count++
+    
+    if (entry.count > config.max) {
+      res.status(429).json({ error: config.message ?? 'Too many requests' })
+      return
+    }
+    
+    next()
+  }
+}
+
+/**
+ * Clean up expired entries from the rate limit store
+ */
+export function cleanupRateLimitStore(): void {
+  const now = Date.now()
+  for (const [ip, entry] of rateLimitStore.entries()) {
+    if (now > entry.resetTime) {
+      rateLimitStore.delete(ip)
+    }
+  }
+}
+
+/**
+ * Get rate limit status for an IP
+ */
+export function getRateLimitStatus(ip: string): { remaining: number; resetTime: number } | null {
+  const entry = rateLimitStore.get(ip)
+  if (!entry) return null
+  return {
+    remaining: Math.max(0, DEFAULT_RATE_LIMIT_CONFIG.max - entry.count),
+    resetTime: entry.resetTime,
+  }
+}
--- a/backend/src/models/index.ts
+++ b/backend/src/models/index.ts
@@ -0,0 +1,63 @@
+/**
+ * Models: Data structures and validation schemas.
+ * 
+ * This module defines the domain models used throughout the application.
+ */
+
+/**
+ * Agent request payload
+ */
+export type AgentRequest = {
+  prompt: string
+  context?: string
+  contextNodes?: AgentContextNode[]
+  connection?: AgentConnection
+  reasoning?: boolean
+}
+
+/**
+ * Context node for agent requests
+ */
+export type AgentContextNode = {
+  id: string
+  content?: string
+}
+
+/**
+ * AI connection configuration
+ */
+export type AgentConnection = {
+  provider: 'openai' | 'local'
+  baseURL?: string
+  apiKey?: string
+  model?: string
+}
+
+/**
+ * Agent response
+ */
+export type AgentResponse = {
+  markdown: string
+}
+
+/**
+ * Agent stream response
+ */
+export type AgentStreamResponse = {
+  markdown: string
+}
+
+/**
+ * Health check response
+ */
+export type HealthResponse = {
+  ok: boolean
+  timestamp: number
+}
+
+/**
+ * Error response
+ */
+export type ErrorResponse = {
+  error: string
+}
--- a/backend/src/repositories/cacheRepository.ts
+++ b/backend/src/repositories/cacheRepository.ts
@@ -0,0 +1,103 @@
+/**
+ * Repositories: Data access layer.
+ * 
+ * This module handles data persistence and retrieval.
+ * It abstracts the underlying storage mechanism.
+ */
+
+/**
+ * Cache entry for expensive computations
+ */
+export type CacheEntry<T> = {
+  /** Unique key for the cache entry */
+  key: string
+  /** Cached data */
+  data: T
+  /** Timestamp (ms) when this entry was created */
+  createdAt: number
+  /** Time-to-live in milliseconds */
+  ttl?: number
+}
+
+/**
+ * In-memory cache implementation
+ */
+export class InMemoryCache {
+  private cache = new Map<string, CacheEntry<unknown>>()
+  private defaultTtl = 5 * 60 * 1000 // 5 minutes
+
+  /**
+   * Get a value from the cache
+   * 
+   * @param key - Cache key
+   * @returns Cached value or null if not found or expired
+   */
+  get<T>(key: string): T | null {
+    const entry = this.cache.get(key) as CacheEntry<T> | undefined
+    if (!entry) return null
+    
+    // Check if entry has expired
+    if (entry.ttl && Date.now() - entry.createdAt > entry.ttl) {
+      this.cache.delete(key)
+      return null
+    }
+    
+    return entry.data
+  }
+
+  /**
+   * Set a value in the cache
+   * 
+   * @param key - Cache key
+   * @param data - Data to cache
+   * @param ttl - Optional time-to-live in milliseconds (uses default if not specified)
+   */
+  set<T>(key: string, data: T, ttl?: number): void {
+    this.cache.set(key, {
+      key,
+      data,
+      createdAt: Date.now(),
+      ttl: ttl ?? this.defaultTtl,
+    })
+  }
+
+  /**
+   * Delete a value from the cache
+   * 
+   * @param key - Cache key
+   */
+  delete(key: string): void {
+    this.cache.delete(key)
+  }
+
+  /**
+   * Clear all entries from the cache
+   */
+  clear(): void {
+    this.cache.clear()
+  }
+
+  /**
+   * Clean up expired entries
+   */
+  cleanup(): void {
+    const now = Date.now()
+    for (const [key, entry] of this.cache.entries()) {
+      if (entry.ttl && now - entry.createdAt > entry.ttl) {
+        this.cache.delete(key)
+      }
+    }
+  }
+
+  /**
+   * Get the number of entries in the cache
+   */
+  size(): number {
+    return this.cache.size
+  }
+}
+
+/**
+ * Global cache instance
+ */
+export const cache = new InMemoryCache()
--- a/backend/src/routes/agentRoutes.ts
+++ b/backend/src/routes/agentRoutes.ts
@@ -0,0 +1,72 @@
+/**
+ * Routes: HTTP request handlers.
+ * 
+ * This module contains the route handlers for the API.
+ * Routes validate input and format output, then call services for business logic.
+ */
+
+import type { AgentRequest, AgentResponse, ErrorResponse } from '../models'
+
+/**
+ * POST /api/agent - Run AI agent
+ * 
+ * Request body: { prompt, context?, contextNodes?, connection? }
+ * Response: { markdown }
+ */
+export async function handleAgentRequest(req: any, res: any): Promise<void> {
+  try {
+    const body = req.body
+    const { buildAgentRequest } = await import('../services/agentService')
+    
+    const built = buildAgentRequest(body)
+    if ('error' in built) {
+      res.status(503).json({ error: built.error } as ErrorResponse)
+      return
+    }
+    
+    const { generateText } = await import('ai')
+    const result = await generateText({
+      model: built.openai as any,
+      prompt: built.fullPrompt,
+    })
+    
+    const { processAgentResponse } = await import('../services/agentService')
+    const response = processAgentResponse(result)
+    res.json(response)
+  } catch (err) {
+    console.error('Agent error:', err)
+    res.status(500).json({ error: (err as Error).message ?? 'Agent request failed' } as ErrorResponse)
+  }
+}
+
+/**
+ * POST /api/agent/stream - Stream AI agent response
+ * 
+ * Request body: { prompt, context?, contextNodes?, connection? }
+ * Response: plain text (markdown) chunks
+ */
+export async function handleAgentStreamRequest(req: any, res: any): Promise<void> {
+  try {
+    const body = req.body
+    const { buildAgentRequest } = await import('../services/agentService')
+    
+    const built = buildAgentRequest(body)
+    if ('error' in built) {
+      res.status(503).json({ error: built.error } as ErrorResponse)
+      return
+    }
+    
+    const { streamText } = await import('ai')
+    const result = streamText({
+      model: built.openai as any,
+      prompt: built.fullPrompt,
+    })
+    
+    res.setHeader('Content-Type', 'text/plain; charset=utf-8')
+    res.setHeader('Transfer-Encoding', 'chunked')
+    result.pipeTextStreamToResponse(res)
+  } catch (err) {
+    console.error('Agent stream error:', err)
+    res.status(500).json({ error: (err as Error).message ?? 'Agent request failed' } as ErrorResponse)
+  }
+}
--- a/backend/src/services/agentService.ts
+++ b/backend/src/services/agentService.ts
@@ -0,0 +1,65 @@
+/**
+ * Services: Business logic layer.
+ * 
+ * This module contains the business logic for the application.
+ * Services coordinate between controllers and repositories.
+ */
+
+import type { AgentRequest, AgentResponse, AgentConnection } from '../models'
+
+/**
+ * Build OpenAI client and full prompt from request body.
+ * Returns { openai, modelId, fullPrompt } or { error }.
+ */
+export function buildAgentRequest(body: AgentRequest): { openai: unknown; modelId: string; fullPrompt: string } | { error: string } {
+  const { prompt, context, contextNodes, connection: conn, reasoning } = body ?? {}
+  const reasoningEnabled = Boolean(reasoning)
+  let baseURL = process.env.AI_BASE_URL?.trim() || null
+  let apiKey = process.env.OPENAI_API_KEY?.trim() || null
+  let modelId = process.env.AI_MODEL?.trim() || (baseURL ? 'local-model' : 'gpt-4o-mini')
+  
+  if (conn && typeof conn === 'object') {
+    const c = conn as AgentConnection
+    const provider = c.provider === 'openai' ? 'openai' : 'local'
+    if (provider === 'local') {
+      baseURL = (typeof c.baseURL === 'string' && c.baseURL.trim()) ? c.baseURL.trim() : baseURL
+      apiKey = (typeof c.apiKey === 'string' && c.apiKey.trim()) ? c.apiKey.trim() : (apiKey || 'lm-studio')
+    } else {
+      baseURL = null
+      apiKey = (typeof c.apiKey === 'string' && c.apiKey.trim()) ? c.apiKey.trim() : apiKey
+    }
+    if (typeof c.model === 'string' && c.model.trim()) modelId = c.model.trim()
+  }
+  
+  if (!baseURL && !apiKey) {
+    return { error: 'No AI configured. Set connection in Settings (AI) or env: OPENAI_API_KEY or AI_BASE_URL.' }
+  }
+  
+  const basePrompt = [
+    typeof prompt === 'string' ? prompt : 'No prompt provided.',
+    context && typeof context === 'string' ? `\n\nAdditional context:\n${context}` : '',
+    Array.isArray(contextNodes) && contextNodes.length > 0
+      ? `\n\nContext from connected nodes:\n${contextNodes.map((n) => (n.content != null ? n.content : `${n.id}: (no content)`)).join('\n\n')}`
+      : '',
+  ].join('')
+  
+  const fullPrompt = reasoningEnabled
+    ? basePrompt + '\n\nRespond in exactly two markdown sections. First: "## Reasoning" with your step-by-step reasoning. Then: "## Output" with only the final answer. No preamble.'
+    : basePrompt + '\n\nRespond with structured markdown only. No preamble.'
+  
+  const { createOpenAI } = require('@ai-sdk/openai')
+  const openai = createOpenAI({
+    apiKey: apiKey || 'lm-studio',
+    ...(baseURL && { baseURL, compatibility: 'compatible' }),
+  })
+  
+  return { openai, modelId, fullPrompt }
+}
+
+/**
+ * Process agent response
+ */
+export function processAgentResponse(result: { text?: string }): AgentResponse {
+  const markdown = result?.text ?? ''
+  return { markdown }
+}