# Development Guide

Guide for contributing to RedditBot development.

---

## Table of Contents

1. [Project Structure](#project-structure)
2. [Development Setup](#development-setup)
3. [Coding Standards](#coding-standards)
4. [Adding a New Service](#adding-a-new-service)
5. [Adding a New Strategy Variant](#adding-a-new-strategy-variant)
6. [Debugging](#debugging)
7. [Common Tasks](#common-tasks)
8. [Known Issues](#known-issues)

---

## Project Structure

```
RedditBot/
├── config.yaml              # Main configuration
├── package.json             # Dependencies and scripts
├── tsconfig.json            # TypeScript config
├── Dockerfile               # Container build
├── docker-compose.yml       # Docker Compose
├── apps/
│   └── dashboard/           # React + Vite operator console
├── packages/
│   └── api-contracts/       # Shared Zod transport contracts
├── scripts/
│   ├── login.ts             # Manual login helper
│   └── inspect-chat-dom.ts  # DOM inspection debug script
└── src/
    ├── index.ts             # Entry point / orchestrator
    ├── config/
    │   └── index.ts         # Config loader + Zod schema
    ├── database/
    │   ├── client.ts        # SQLite setup + migrations
    │   └── repositories.ts  # Repository classes
    ├── reddit/
    │   └── api.ts           # Reddit API client
    ├── ai/
    │   └── openrouter.ts    # OpenRouter AI client
    ├── browser/
    │   ├── client.ts        # Playwright browser manager
    │   ├── message-page.ts  # DM compose automation
    │   └── media-downloader.ts # Media download
    ├── services/
    │   ├── monitor.ts           # Post discovery
    │   ├── processor.ts         # Processing pipeline
    │   ├── response-checker.ts  # Response monitoring
    │   ├── strategy-selector.ts # A/B testing
    │   ├── chat.ts              # Chat scraping + messaging
    │   ├── media.ts             # Media management
    │   ├── media-sync.ts        # Media sync scheduler
    │   └── auto-reply.ts        # Auto-reply service
    ├── utils/
    │   ├── logger.ts      # Winston logger
    │   ├── rate-limiter.ts # Rate limiting
    │   ├── retry.ts       # Retry wrapper
    │   └── image.ts       # Image utilities
    └── web/                 # Express API, events, and dashboard hosting
```

---

## Development Setup

### 1. Install Dependencies

```bash
npm install
```

### 2. Configure

Copy and edit `config.yaml`:

```bash
cp config.yaml config.yaml.backup  # Backup existing
# Edit config.yaml with your settings
```

### 3. Set Environment Variables

```bash
export REDDIT_USERNAME="your-username"
export REDDIT_PASSWORD="your-password"
export OPENROUTER_API_KEY="sk-or-v1-your-key"
```

### 4. Initial Login

```bash
# Open browser for manual login
npm run login
```

### 5. Start Development Server

```bash
# Terminal 1: backend reload with tsx
npm run dev

# Terminal 2: Vite frontend with /api proxied to port 3000
npm run dashboard:dev

# Production build: server plus apps/dashboard/dist
npm run build && npm start
```

### 6. Access Dashboard

During frontend development, open the URL printed by Vite (normally
http://localhost:5173). The Express dashboard remains on http://localhost:3000
for production/fallback verification.

Useful frontend checks:

```bash
npm run dashboard:typecheck
npm run dashboard:build
npx vitest run tests/dashboard
```

---

## Coding Standards

### TypeScript

- **Strict mode**: No `any` types (use `unknown` with type guards)
- **Interfaces**: Define interfaces for all data structures
- **Null checks**: Use optional chaining (`?.`) and nullish coalescing (`??`)
- **Async/Await**: Use async/await, not `.then()` chains

```typescript
// Good
interface PostData {
  id: string;
  subreddit: string;
  author: string;
}

async function fetchPost(id: string): Promise<PostData> {
  const response = await api.get(`/posts/${id}`);
  return response.data;
}

// Bad
async function fetchPost(id: any): Promise<any> {
  return api.get(`/posts/${id}`).then(r => r.data);
}
```

### Logging

Use `winston` logger, never `console.log`:

```typescript
// Good
this.logger.info("Processed post {id}", { id: post.id });
this.logger.warn("AI refusal detected", { postId: post.id });
this.logger.error("Failed to send DM", { error: err.message });

// Bad
console.log("Processed post", post.id);
```

### Error Handling

Use try/catch with structured error handling:

```typescript
try {
  await this.processPost(post);
} catch (err) {
  this.logger.error("Post processing failed", {
    postId: post.id,
    error: err instanceof Error ? err.message : String(err)
  });
  // Don't throw - allow other posts to be processed
}
```

### Service Structure

Follow single responsibility:

```typescript
class NewService {
  constructor(
    private config: Config,
    private dependency: ExistingService,
    private logger: Logger
  ) {}

  async doSomething(input: string): Promise<Result> {
    // Validate input
    if (!input) {
      throw new Error("Input is required");
    }

    // Do work
    const result = await this.dependency.process(input);

    // Return result
    return result;
  }
}
```

### File Organization

- One class per file (except repositories which share one file)
- Services in `src/services/`
- Utilities in `src/utils/`
- External integrations in their own folders (`src/ai/`, `src/reddit/`, `src/browser/`)

---

## Adding a New Service

### 1. Create the Service File

```typescript
// src/services/new-service.ts
import { Config } from '../config';
import { Logger } from '../utils/logger';

interface NewServiceDeps {
  config: Config;
  logger: Logger;
  // other dependencies
}

interface Result {
  success: boolean;
  data?: any;
  error?: string;
}

export class NewService {
  constructor(private deps: NewServiceDeps) {}

  async execute(input: string): Promise<Result> {
    const { config, logger } = this.deps;
    
    logger.info("NewService executing", { input });
    
    // Implementation here
    
    return { success: true };
  }
}
```

### 2. Add to Dependencies Interface

If the service needs other services, add them to the interface:

```typescript
interface NewServiceDeps {
  config: Config;
  logger: Logger;
  redditApi: RedditApi;
  openrouter: OpenRouterService;
}
```

### 3. Wire Up in main()

In `src/index.ts`, add initialization:

```typescript
const newService = new NewService({
  config,
  logger,
  redditApi,
  openrouter
});

// If it needs to run periodically:
setInterval(() => {
  newService.execute(someInput).catch(err => {
    logger.error("NewService error", { error: err.message });
  });
}, intervalMs);
```

### 4. Add to the Web API and Dashboard (Optional)

If the service needs an API, add a focused router under `src/web/routes/` and
mount it from `src/web/server.ts`. Define its transport schema in
`packages/api-contracts`; do not expose repository rows directly.

```typescript
router.get('/new-service', async (req, res) => {
  try {
    const result = await newService.execute(req.query.input as string);
    res.json(result);
  } catch (err) {
    res.status(500).json({ error: (err as Error).message });
  }
});
```

Add frontend behavior under `apps/dashboard/src/features/<feature>/` and drive
it with Testing Library and MSW tests under `tests/dashboard/`.

### 5. Update Config (If Needed)

Add new configuration options to:
- `config.yaml`
- `src/config/index.ts` Zod schema
- Configuration documentation

---

## Adding a New Strategy Variant

### 1. Add to config.yaml

```yaml
strategyVariants:
  - name: "existing_variant"
    prompt: "Existing prompt..."
    enabled: true
  
  - name: "new_variant"
    prompt: |
      Write a friendly message that references the image content.
      Be specific and genuine. Keep it under 2 sentences.
    enabled: true
```

### 2. No Code Changes Needed

The `StrategySelector` automatically picks up new variants from the config. The algorithm will:

1. Include the new variant in random exploration
2. Track its response rate once messages are sent
3. Promote it to exploitation if it has good stats

### 3. Monitor Performance

Check performance via the dashboard or API:

```bash
curl http://localhost:3000/api/analytics/by-strategy
```

---

## Debugging

### Browser Debugging

Run with visible browser:

```yaml
# config.yaml
browser:
  headless: false
```

Or set environment variable:

```bash
BROWSER_HEADLESS=false npm run dev
```

### DOM Inspection

Use the debug endpoint to inspect Reddit's shadow DOM:

```bash
curl -X POST http://localhost:3000/api/debug/inspect-dom
```

Or run the standalone script:

```bash
npx tsx scripts/inspect-chat-dom.ts
```

### Logging

Adjust log level by modifying `src/utils/logger.ts`:

```typescript
const logger = winston.createLogger({
  level: 'debug',  // Change from 'info' to 'debug'
  // ...
});
```

### Database Inspection

Open the database with SQLite viewer:

```bash
# Install sqlite3 if needed
brew install sqlite3

# Open database
sqlite3 data/reddit-bot.db

# Query
SELECT * FROM sent_messages LIMIT 5;
```

### Network Debugging

Enable axios debug:

```typescript
// In src/reddit/api.ts
import axios from 'axios';
axios.defaults.debug = true;
```

---

## Common Tasks

### Add a New Subreddit

```yaml
# config.yaml
reddit:
  subreddits:
    - gonewild
    - ratemyboobs
    - new_subreddit_name  # Add here
```

### Change AI Model

```yaml
# config.yaml
openrouter:
  model: "new-model-name"
  fallbackModels:
    - "fallback-model-1"
    - "fallback-model-2"
```

### Adjust Rate Limits

```yaml
# config.yaml
rateLimit:
  minDelayMs: 45000      # Increase delay
  maxMessagesPerHour: 15  # Reduce cap
  jitterMs: 20000        # More jitter
```

### Enable Dry Run

```yaml
# config.yaml
dryRun: true  # Logs all actions without sending
```

Or via dashboard: `PUT /api/config` with `{"dryRun": true}`

### Add Database Column

```typescript
// In src/database/client.ts
function runMigrations(db: Database) {
  // ... existing migrations ...

  // Check if column exists
  const tableInfo = db.prepare(`PRAGMA table_info(sent_messages)`).all();
  const hasNewColumn = tableInfo.some((col: any) => col.name === 'new_column');

  if (!hasNewColumn) {
    db.exec("ALTER TABLE sent_messages ADD COLUMN new_column TEXT");
  }
}
```

### Add New API Endpoint

```typescript
// In src/web/server.ts
import { Request, Response } from 'express';

server.app.get('/api/new-endpoint', async (req: Request, res: Response) => {
  try {
    const result = await someService.doSomething();
    res.json({ success: true, data: result });
  } catch (err) {
    res.status(500).json({ error: (err as Error).message });
  }
});
```

---

## Known Issues

### Hardcoded Username in ChatService

`ChatService` has `myUsername = 'Upset_Marsupial1006'` hardcoded in JavaScript evaluation scripts. This should be parameterized from config.

**Fix needed**: Pass username to `page.evaluate()` calls.

### Shadow DOM Fragility

Reddit frequently updates their `faceplate-*` components. Shadow DOM traversal code may break without warning.

**Mitigation**: Use `scripts/inspect-chat-dom.ts` to debug when selectors change.

### Dashboard Migration Boundary

The React application lives in `apps/dashboard`. A production build is required
before the Express server starts; there is no legacy HTML fallback.

The repository has automated service, contract, component, and transport tests.
Manual browser verification is still required for Reddit DOM changes and the
final dashboard cutover.