# Claude Development Guide for ECM Control

This file contains important information for Claude Code when working on the ECM Control project.

## Project Overview

ECM Control is an Espresso Coffee Machine Control System built with:
- **Backend**: Python, FastAPI, SQLite
- **Frontend**: HTMX, Bootstrap, Vanilla JavaScript  
- **Hardware**: Raspberry Pi GPIO, relay control, Acaia scale integration
- **Package Manager**: UV (not pip/poetry)
- **Database**: SQLite with schema in `src/ecm_control/database/schema.sql`

## Package Management - IMPORTANT

**Always use UV, never use pip or poetry:**

```bash
# Install dependencies
uv add package-name

# Remove dependencies  
uv remove package-name

# Run commands in virtual environment
uv run python script.py

# Sync dependencies
uv sync
```

## Running the Application

**Web Application:**
```bash
uv run python run.py web --log-level DEBUG --port 8000
```

**GPIO Control Service:**
```bash
# With actual hardware
uv run python run.py gpio

# With mock hardware (for development)
uv run python run.py gpio --mock --log-level DEBUG
```

**Database Management:**
```bash
# Initialize database
uv run python run.py db init

# Reset database (deletes all data)
uv run python run.py db reset
```

## Development Commands

**Testing endpoints:**
- Web interface: http://localhost:8000
- Debug with console logging enabled in browser
- Server logs show detailed request/response info at DEBUG level

**Database queries for debugging:**
```bash
uv run python -c "
import sys; sys.path.insert(0, 'src')
from ecm_control.database import DatabaseManager
db = DatabaseManager()
recipes = db.execute_query('SELECT * FROM recipes')
print(recipes)
"
```

## Code Style and Conventions

**File Structure:**
- `src/ecm_control/` - Main package
- `templates/` - Jinja2 HTML templates
- `static/` - CSS/JS assets
- `run.py` - Main entry point (use this instead of module execution)

**Logging:**
- Use `from ecm_control.utils.logging_config import get_logger`
- Logger name: `logger = get_logger('module_name')`
- DEBUG level shows detailed request/exception info

**Database:**
- Use `DatabaseManager` class for all DB operations
- Schema in `src/ecm_control/database/schema.sql`
- Models in `src/ecm_control/models/__init__.py`

## Git Workflow

**When making changes:**
```bash
git add .
git commit -m "Description of changes

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>"
```

**Commit message format:**
- Use conventional commits (feat:, fix:, docs:, etc.)
- Include the Claude Code footer
- Be descriptive about what changed and why

## Testing and Deployment

**Before committing:**
1. Test web interface functionality
2. Test GPIO service in mock mode
3. Verify database operations work
4. Check logs for errors/warnings

**Hardware Testing:**
- Use `--mock` flag for development without GPIO hardware
- Real hardware requires Raspberry Pi with GPIO pins
- Scale integration uses mock implementation (pyacaia had build issues)

**Production Deployment:**
- Copy `ecm-control.service` to `/etc/systemd/system/`
- Update paths in service file for your installation
- Use `systemctl` to manage the service

## Common Issues and Solutions

**"No module named ecm_control":**
- Use `uv run python run.py` instead of `uv run python -m ecm_control`

**HTMX not updating UI:**
- Check browser console for JavaScript errors
- Verify `hx-target` selectors match element IDs
- Ensure `hx-swap="innerHTML"` is specified for content replacement

**Database errors:**
- Reset database: `uv run python run.py db reset`
- Check file permissions on `ecm_control.db`

**GPIO permissions (on Raspberry Pi):**
```bash
sudo usermod -a -G gpio $USER
# Then log out and back in
```

**GPIO pin conflicts:**
```bash
# Show safe GPIO pins and current configuration
uv run python run.py gpio-info

# Show pins during GPIO service startup
uv run python run.py gpio --show-pins
```

**Safe GPIO pins for buttons:** 4, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27

**Avoid these pins:** 5, 6, 7, 9 (SPI), 14, 15 (UART), 2, 3 (I2C)

**Form validation errors (422):**
- Check FastAPI endpoint parameter types
- Handle empty strings vs None for optional fields
- Use `str = Form("")` and convert to int/None in endpoint

## Architecture Notes

**Web Application:**
- FastAPI with dependency injection
- HTMX for dynamic UI updates
- Bootstrap for styling
- Jinja2 templates with partials for HTMX responses

**GPIO Control:**
- Async event-driven architecture
- Mock implementations for development
- Real-time shot monitoring with scale feedback
- Database logging of all shot attempts

**Database Schema:**
- `recipes` - extraction recipes (grams + timeout)
- `buttons` - physical GPIO buttons mapped to recipes
- `shots` - log of all extraction attempts
- `settings` - configurable system parameters

## File Locations

**Key configuration files:**
- `pyproject.toml` - Project dependencies and metadata
- `ecm-control.service` - Systemd service configuration
- `src/ecm_control/database/schema.sql` - Database schema
- `src/ecm_control/web/__init__.py` - FastAPI web application
- `src/ecm_control/gpio/__init__.py` - GPIO control logic

**Templates:**
- `templates/base.html` - Base template with navigation
- `templates/partials/` - HTMX response templates
- `static/css/style.css` - Custom styles
- `static/js/app.js` - Frontend JavaScript

Remember: This is a hardware control system, so safety and reliability are important. Always test thoroughly and handle errors gracefully.