# Findings & Research Documentation

**Last Updated:** 2026-02-15T00:00:00.000Z  
**JIRA:** RECIPE-0001  
**Status:** Initialized

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## Purpose

This document tracks research findings, analysis results, and technical discoveries made during development. Each agent (Planner, Developer, Reviewer) appends findings as they work through the pipeline.

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## Initial Codebase Analysis

### Language & Framework
- **Primary Language**: TypeScript 5.9.3
- **Framework**: SvelteKit 2.48.5 with Svelte 5.43.8
- **Runtime**: Node.js 22+
- **Package Manager**: npm

### Project Type
Progressive Web Application (PWA) for extracting recipes from Instagram posts and uploading them to Tandoor Recipe Manager.

### Architecture Style
**Hexagonal Architecture** (Ports and Adapters):
- Domain logic in `src/lib/server/`
- External system adapters: Instagram, Tandoor, LLM, Browser
- Clear separation between client and server code

### Key Technical Components
1. **Queue Management System**: In-memory FIFO queue with async processing
2. **Three-Phase Pipeline**: Extraction → Parsing → Uploading
3. **Real-Time Updates**: Server-Sent Events (SSE) for progress tracking
4. **Push Notifications**: Web Push API for background notifications
5. **PWA Features**: Service worker, manifest, install prompts

### Design Patterns Identified
- **Singleton**: QueueManager, QueueProcessor, PushNotificationService
- **Factory**: createLLM(), createBrowserContext(), initializeBrowser()
- **Observer**: Queue subscription system, SSE streaming
- **Adapter**: Instagram, Tandoor, LLM, Browser adapters
- **Strategy**: Multiple extraction methods with fallback

### Dependencies Overview
**Production** (6 dependencies):
- Browser automation: `playwright`
- LLM integration: `openai`
- Utilities: `uuid`, `date-fns`, `zod`

**Development** (26+ dependencies):
- Framework: `@sveltejs/kit`, `svelte`, `vite`
- Testing: `vitest`, `@vitest/browser-playwright`
- Styling: `tailwindcss`
- Tooling: `typescript`, `eslint`, `prettier`

### File Structure
```
52 total TypeScript/JavaScript files
├── 39 TypeScript files (.ts)
├── 10+ Svelte components (.svelte)
├── 3 JavaScript config files (.js)
└── Multiple test files (.spec.ts)
```

### Code Quality Indicators
- **Strict TypeScript**: `strict: true` enabled
- **Comprehensive Testing**: 138 tests across unit, integration, and browser tests
- **Linting**: ESLint with TypeScript and Svelte plugins
- **Formatting**: Prettier with Svelte and Tailwind plugins
- **Type Safety**: Zod schemas for runtime validation

### Environment Configuration
Required variables:
- `OPENAI_API_KEY` - LLM access
- `TANDOOR_URL` - Recipe manager URL (optional)
- `TANDOOR_TOKEN` - API authentication (optional)
- `QUEUE_CONCURRENCY` - Processing limit (default: 2)
- `QUEUE_MAX_RETRIES` - Retry attempts (default: 3)

### Deployment Setup
- **Docker**: Dockerfile with Node.js 22 Alpine + Chromium
- **HTTPS**: Local SSL certificates for PWA features
- **Production**: Node.js adapter for SvelteKit

### Notable Features
1. **Multi-Method Extraction**: 4-strategy cascade with intelligent fallback
2. **Progress Tracking**: Real-time callbacks throughout extraction pipeline
3. **Thumbnail Validation**: HTTP status code checking for image URLs
4. **Retry Logic**: Configurable retry attempts for failed extractions
5. **Scheduler**: Background task execution with authentication

---

## Technical Debt & Opportunities

### Identified Issues
1. **Deprecated Endpoints**: `/api/extract` returns 410 Gone (migration helper)
2. **In-Memory Queue**: No persistence - items lost on server restart
3. **Single Instance**: Queue state not shared across multiple server instances

### Potential Improvements
1. **Queue Persistence**: Redis or database-backed queue for durability
2. **Horizontal Scaling**: Shared queue state for multi-instance deployments
3. **Rate Limiting**: Instagram request throttling to avoid blocks
4. **Caching**: Extracted content caching to reduce redundant processing

---

## Research Findings

*This section will be populated by the Planner agent during task analysis.*

### [Planner] Research Notes - RECIPE-0001 (2026-02-15)

**Task:** Fix model loading issue and frontend error display

#### Issue 1: Model Loading - "400 No models loaded"
**Research Date:** 2026-02-15  
**Source:** Stack trace analysis, OpenAI SDK documentation, LM Studio/LiteLLM API patterns

**Problem Analysis:**
- Error occurs at `detectRecipe()` in [src/lib/server/parser.ts](src/lib/server/parser.ts#L30)
- OpenAI-compatible APIs (LM Studio, LiteLLM, Ollama, etc.) often require models to be explicitly loaded
- Current implementation assumes model is already loaded
- Error message contains provider-specific instructions ("use the 'lms load' command")

**OpenAI-Compatible Model Loading Patterns:**
1. **LM Studio**: Uses `/v1/models` endpoint to list available models
   - Loaded models appear in response with `"id": "model-name"`
   - No programmatic loading endpoint (manual load in UI)
   
2. **LiteLLM**: Uses `/v1/models` to list loaded models
   - Models must be configured in server startup
   - No dynamic loading endpoint
   
3. **Ollama**: Uses `/api/tags` for model list and `/api/pull` for loading
   - Different API structure (not `/v1` prefix)
   
4. **Generic OpenAI-compatible**: Most follow OpenAI's `/v1/models` endpoint
   - No standard for dynamic model loading
   - Usually require pre-configuration

**Solution Approach:**
- Check if model exists via `client.models.list()`
- If model not found/loaded, provide clear user-facing error
- Remove provider-specific error messages
- Add notification when model check succeeds
- Consider future enhancement: detect provider type and attempt auto-load if supported

**Files Affected:**
- [src/lib/server/llm.ts](src/lib/server/llm.ts) - Add model availability check
- [src/lib/server/parser.ts](src/lib/server/parser.ts) - Handle model not loaded error
- [src/lib/server/queue/QueueProcessor.ts](src/lib/server/queue/QueueProcessor.ts) - User notification

---

#### Issue 2: Frontend Error Display - "[object Object]"
**Research Date:** 2026-02-15  
**Source:** Code analysis of QueueItemCard.svelte, types.ts, QueueManager.ts

**Problem Analysis:**
- Error structure is an object: `{ phase, message, recoverable, timestamp }`
- Frontend displays `{item.error}` directly (line 205 of QueueItemCard.svelte)
- Svelte renders object.toString() → "[object Object]"

**Current Implementation:**
```typescript
// types.ts - Error is an object
error?: {
  phase: ProcessingPhase;
  message: string;
  recoverable: boolean;
  timestamp: string;
}

// QueueItemCard.svelte line 205 - Displays object directly
<div class="text-sm text-red-700 mt-1">{item.error}</div>
```

**Solution:**
Change to: `{item.error?.message || item.error}`
- Handles object error (gets .message)
- Handles legacy string errors (fallback)
- Type-safe with optional chaining

**Files Affected:**
- [src/routes/components/QueueItemCard.svelte](src/routes/components/QueueItemCard.svelte#L205) - Display error.message

---

#### Dependencies & Constraints (from ARCHITECTURE.md)
- Using `openai@^4.20.0` SDK
- Environment: `OPENAI_BASE_URL`, `OPENAI_API_KEY`, `LLM_MODEL`
- Current config example: `http://192.168.1.10:1234/v1` (LM Studio)
- Must maintain OpenAI-compatible API contract
- No assumption about specific provider implementation

#### Code Style Requirements (from CODE_STYLE.md)
- Use SvelteKit `$env/dynamic/private` for env vars (already correct)
- Error handling: try-catch with descriptive messages
- Console logging: `[Component] Message` format
- Type safety: TypeScript strict mode enabled

<!-- Planner appends findings here -->

---

### [Developer] Implementation Notes

<!-- Developer appends findings here -->

---

### [Reviewer] Review Notes

<!-- Reviewer appends findings here -->

---

## API Endpoint Catalog

### Active Endpoints

#### Queue Management
- `POST /api/queue` - Enqueue Instagram URL for processing
- `GET /api/queue` - List queue items (supports filtering, pagination)
- `GET /api/queue/stream` - SSE stream for real-time updates
- `GET /api/queue/{id}` - Get specific queue item details
- `DELETE /api/queue/{id}` - Remove item from queue
- `POST /api/queue/{id}/retry` - Retry failed extraction

#### Push Notifications
- `POST /api/notifications/subscribe` - Subscribe to push notifications
- `DELETE /api/notifications/subscribe` - Unsubscribe from notifications
- `GET /api/notifications/vapid-key` - Get VAPID public key

#### Health & Status
- `GET /api/health` - Application health check
- `GET /api/llm-health` - LLM service availability check

#### Tandoor Integration
- `POST /api/tandoor` - Upload recipe to Tandoor
- `GET /api/tandoor-config` - Get Tandoor configuration status

#### Legacy/Deprecated
- `POST /api/extract` - ⚠️ Deprecated (returns 410 Gone)

---

## Known Constraints

### Browser Automation
- Requires Chromium/Chrome installation
- Headless mode used in production
- Cookie handling for authenticated Instagram content

### LLM Integration
- Requires OpenAI-compatible API endpoint
- Configurable model selection
- Structured output using Zod schemas

### Tandoor Integration
- Optional feature (disabled without credentials)
- Requires Tandoor API token
- Supports ingredient partitioning across steps

### SSL Requirements
- HTTPS required for Service Worker registration
- Local development uses self-signed certificates
- Certificates managed via external Caddy CA

---

## Testing Coverage

### Test Distribution
- **Unit Tests**: Core logic validation
- **Integration Tests**: Multi-component workflows
- **API Tests**: Endpoint behavior verification
- **Browser Tests**: Svelte component rendering

### Test Files
- `queue-manager.spec.ts`
- `queue-processor.spec.ts`
- `queue-api.spec.ts`
- `queue-sse.spec.ts`
- `scheduler.spec.ts`
- `instagram-url-validation.spec.ts`
- `thumbnail-validation.spec.ts`
- `extraction-url-validation.integration.spec.ts`
- `page.svelte.spec.ts`

### Mock Strategy
- Environment variables mocked via `vi.mock('$env/dynamic/private')`
- External services mocked at module level
- Browser automation mocked for unit tests

---

## Documentation Inventory

### Existing Documentation
- `README.md` - Project overview and setup
- `docs/API.md` - API endpoint specifications
- `docs/MIGRATION.md` - Migration guides
- `docs/SVELTEKIT_SSR_GUIDE.md` - SSR implementation notes
- `docs/TESTING.md` - Testing guide and mocking patterns
- `docs/Tandoor (2.3.6).yaml` - OpenAPI spec for Tandoor

### Plan Documentation
`docs/plans/` contains 20+ implementation plans:
- Execution plans for completed features
- Technical specifications
- Story breakdowns with acceptance criteria

### Outcome Documentation
`docs/outcomes/` contains 20+ outcome reports:
- Implementation summaries
- Changes made
- Testing results
- Lessons learned

---

## Agent Pipeline Notes

### Build Commands
- **Build**: `npm run build`
- **Test**: `npm test` (alias for `npm run test:unit -- --run`)
- **Dev**: `npm run dev`
- **Lint**: `npm run lint`
- **Format**: `npm run format`

### Development Workflow
1. Make changes in `src/`
2. Run tests: `npm test`
3. Verify build: `npm run build`
4. Test locally: `npm run dev`

### Continuous Integration
- ESLint checks code quality
- Prettier enforces formatting
- TypeScript checks type safety
- Vitest runs test suite

---

## Next Steps

This document will be updated by subsequent agents:
1. **Planner**: Append research findings and analysis
2. **Developer**: Document implementation discoveries
3. **Reviewer**: Record review observations and recommendations

---

### [Planner] Research Notes - RECIPE-0002 (2026-02-16)

**Task:** Complete PWA implementation (installability, push notifications, share target)

#### PWA Documentation Research
**Research Date:** 2026-02-16  
**Sources:** MDN Web Docs, web.dev, W3C specifications

**Progressive Web Apps (PWA) - Key Requirements:**
1. **Web App Manifest** (`manifest.json`)
   - Required members: `name` or `short_name`, `icons` (192x192 PNG minimum), `start_url`, `display`
   - Share target support via `share_target` member (method, action, params)
   - Icons should include 192x192 and 512x512 sizes for optimal display
   - Browser compatibility: Chrome/Edge (full), Firefox/Safari (limited for share_target)

2. **Service Worker**
   - Must be registered to enable offline functionality
   - Lifecycle: install → activate → fetch events
   - Required for push notifications
   - Must be served over HTTPS (or localhost)

3. **HTTPS Requirement**
   - Mandatory for service worker registration
   - Required for push notifications and other secure contexts
   - Local development: `http://localhost` is treated as secure

4. **Installability Criteria** (from MDN/web.dev):
   - Valid manifest with required members
   - Service worker registered with fetch event handler
   - Served over HTTPS
   - At least one 192x192 PNG or SVG icon
   - Display mode set (fullscreen, standalone, minimal-ui)

**Push Notifications (Web Push API):**
- Requires service worker to receive push events
- VAPID authentication (application server keys) required for Chrome
- Subscription process: permission → subscribe → store subscription → send push
- Push service (browser vendor controlled) routes messages
- Notification permissions: default, granted, denied
- Best practice: request permission after user interaction

**Web Share Target API:**
- Registers PWA as share destination
- Configuration via manifest `share_target` member
- Supports GET or POST methods
- `params` define query string mapping (title, text, url)
- Files can be shared via POST with `multipart/form-data`
- Currently Chrome/Edge only (experimental)
- App must be installed to appear in share sheet

#### Current Implementation Analysis
**Research Date:** 2026-02-16  
**Files Analyzed:** manifest.json, service-worker.ts, app.html, svelte.config.js, PWAInstallManager.ts, PushNotificationManager.ts

**Manifest Analysis (`static/manifest.json`):**
- ✅ Has all required PWA members (name, short_name, start_url, display, scope, theme_color, background_color)
- ✅ Share target configured correctly (GET /share with title/text/url params)
- ⚠️ Icons reference `/favicon.png` but file does NOT exist in static folder
- ⚠️ Uses same icon path for both 192x192 and 512x512 sizes
- ℹ️ Missing optional but recommended members: `description`, `screenshots`, `categories`

**Service Worker Analysis (`src/service-worker.ts`):**
- ✅ Native SvelteKit service worker (migrated from vite-pwa plugin)
- ✅ Install event: caches all build assets and static files
- ✅ Activate event: cleans up old caches
- ✅ Fetch event: cache-first for assets, network-first with cache fallback for others
- ✅ Push event handler: processes push messages, shows notifications with actions
- ✅ Notification click handler: opens/focuses app, handles action buttons
- ✅ Notification close handler: tracks dismissals
- ✅ Background sync handler: supports retry operations
- ✅ Message handler: supports service worker communication
- ✅ Global error handlers present

**Service Worker Registration (`svelte.config.js`):**
- ✅ `serviceWorker.register: true` enabled
- ✅ SvelteKit handles registration automatically

**Manifest Link (`src/app.html`):**
- ✅ `<link rel="manifest" href="/manifest.json">` present in head

**Client-Side Managers:**
- ✅ `PushNotificationManager.ts`: Full implementation with permission, subscribe, unsubscribe
- ✅ `PWAInstallManager.ts`: beforeinstallprompt handling, install prompt triggering
- ✅ Both are SSR-safe with browser guards

**Share Target (`/share` route):**
- ✅ Route exists at `src/routes/share/+page.svelte`
- ✅ Parses query params (text, url) from share target
- ✅ Extracts Instagram URLs from shared text
- ✅ Auto-processes URLs on mount
- ✅ Enqueues items and redirects to dashboard

**Icons/Assets Issue:**
- ⚠️ **CRITICAL**: `manifest.json` references `/favicon.png` but file doesn't exist
- ✅ `src/lib/assets/favicon.svg` exists (used in layout)
- ⚠️ No PNG icons in `static/` folder
- ⚠️ Service worker references `/favicon.png` for notifications

**Push Notifications Infrastructure:**
- ✅ VAPID keys configured in `queueConfig.push` (uses env vars or defaults)
- ✅ Server endpoint: `/api/notifications/vapid-key` (GET)
- ✅ Server endpoint: `/api/notifications/subscribe` (POST/DELETE)
- ✅ PushNotificationService stores subscriptions in-memory
- ℹ️ Note: Subscriptions are not persisted (lost on restart)

#### What Works Already:
1. **PWA Structure**: Complete Native SvelteKit PWA implementation
2. **Service Worker**: Fully functional with caching, push, notifications
3. **Push Notifications**: Client and server infrastructure in place
4. **Share Target**: Configured in manifest and `/share` route working
5. **Install Prompts**: PWAInstallManager ready to trigger install
6. **HTTPS**: App served at https://localhost:5173/

#### What Needs Attention:
1. **Icons**: Create PNG icons (192x192, 512x512) from existing SVG
2. **Icon Verification**: Ensure icons are properly sized and optimized
3. **Installability Testing**: Verify all criteria met via chrome://pwa-internals
4. **Push Notification Testing**: Verify VAPID key generation and push flow
5. **Share Target Testing**: Test share from external apps (Instagram)
6. **Manifest Enhancement**: Add description, categories for better discoverability

#### Dependencies & Constraints (from ARCHITECTURE.md, CODE_STYLE.md):
- Using native SvelteKit PWA (no plugins needed)
- Service worker: `$service-worker` module provides build, files, version
- Environment: uses `$env/dynamic/private` for server configs
- HTTPS required (already configured at https://localhost:5173/)
- TypeScript strict mode enabled
- All file paths must use SvelteKit path aliases (`$lib`, `$service-worker`)

#### Code Style Requirements (from CODE_STYLE.md):
- FilesNaming: manifest.json, service-worker.ts, lowercase for utilities
- Type annotations required for public APIs
- SSR-safe code: all browser API usage must be guarded with `browser` check
- Error handling: try-catch with descriptive messages
- Comments: JSDoc for public APIs, inline for complex logic

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**Document Version:** 1.1  
**Last Updated by:** Planner Agent  
**Next Update:** Developer Agent