# Coding Standards

## PHP

- **Version:** PHP 7.4 (server standard)
- **Autoloading:** PSR-4 via Composer
- **Namespaces:** Use project-level namespaces (e.g., `DMCall\Core\`, `EmailIntelligence\`)
- **Database access:** Always use wrapper classes (`Database.php`, `QueryAdapter.php`), never raw `$db` queries
- **MongoDB upserts:** Use `insertOrUpdate()` method, not raw `upsert()`
- **Error handling:** Log to file via `error_log()` or `file_put_contents()` to logs directory
- **Configuration:** Constants via `define()` in `config.php`, never hardcode credentials
- **Timezone:** `Europe/Bucharest` for all date operations

### PHP Patterns Used
```php
// Singleton database connections
$db = Database::getInstance();

// Config as constants
define('MONGODB_HOST', '127.0.0.1');

// Error logging
ini_set('error_log', __DIR__ . '/../logs/php_errors.log');

// Fatal error handler
register_shutdown_function(function() { ... });
```

## JavaScript

- **No build step.** Vanilla JS, no frameworks, no npm for frontend
- **Libraries via CDN:** marked.js, highlight.js, Chart.js as needed
- **DOM manipulation:** Native `document.querySelector()`, no jQuery
- **API calls:** Native `fetch()` API
- **Module pattern:** Single app object (e.g., `DMCall`, `App`) with methods

## File Organization

- Entry points in `public/`
- Classes in `src/`
- Config in `config/`
- Logs in `logs/` (gitignored)
- Vendor dependencies via Composer in `vendor/`

## Node.js

- Server runs Node.js v10.19 — do not use modern syntax
- Do not use `node -c` for JS syntax checks
- Puppeteer used for scraping tasks

## Documentation

- Every project must have a `PROJECT_OVERVIEW.md` at root
- AI-facing context docs should use `CLAUDE.md` or `__databaseDescriptionAI.md` naming
- Include calling maps in file headers for complex scripts
- Document API endpoints with examples