# AGENTS.md - AI Coding Agent Guidelines

This document provides guidelines for AI coding agents working in the labhelper repository.

## Project Overview

- **Type**: Django web application (lab inventory management system)
- **Python**: 3.13.7
- **Django**: 5.2.9
- **Database**: SQLite (development)
- **Virtual Environment**: `.venv/`

## Build/Run Commands

### Development Server

```bash
python manage.py runserver              # Start dev server on port 8000
python manage.py runserver 0.0.0.0:8000 # Bind to all interfaces
```

### Database Operations

```bash
python manage.py makemigrations         # Create migration files
python manage.py makemigrations boxes   # Create migrations for specific app
python manage.py migrate                # Apply all migrations
python manage.py showmigrations         # List migration status
```

### Testing

```bash
# Run all tests
python manage.py test

# Run tests for a specific app
python manage.py test boxes

# Run a specific test class
python manage.py test boxes.tests.TestClassName

# Run a single test method
python manage.py test boxes.tests.TestClassName.test_method_name

# Run tests with verbosity
python manage.py test -v 2

# Run tests with coverage
coverage run manage.py test
coverage report
coverage html  # Generate HTML report
```

### Django Shell

```bash
python manage.py shell                  # Interactive Django shell
python manage.py createsuperuser        # Create admin user
python manage.py collectstatic          # Collect static files
```

### Production

```bash
gunicorn labhelper.wsgi:application     # Run with Gunicorn
```

### Custom Management Commands

```bash
# Create default users and groups
python manage.py create_default_users

# Clean up orphaned files from deleted things
python manage.py clean_orphaned_files
python manage.py clean_orphaned_files --dry-run

# Clean up orphaned images and thumbnails
python manage.py clean_orphaned_images
python manage.py clean_orphaned_images --dry-run
```

## Code Style Guidelines

### Python Style

- Follow PEP 8 conventions
- Use 4-space indentation (no tabs)
- Maximum line length: 79 characters (PEP 8 standard)
- Use single quotes for strings: `'string'`
- Use double quotes for docstrings: `"""Docstring."""`

### Import Order

Organize imports in this order, with blank lines between groups:

```python
# 1. Standard library imports
import os
import sys
from pathlib import Path

# 2. Django imports
from django.db import models
from django.contrib import admin
from django.shortcuts import render, redirect
from django.http import HttpResponse, JsonResponse

# 3. Third-party imports
import requests
from markdown import markdown

# 4. Local application imports
from .models import MyModel
from .forms import MyForm
```

### Naming Conventions

| Type | Convention | Example |
|------|------------|---------|
| Modules | lowercase_with_underscores | `user_profile.py` |
| Classes | PascalCase | `UserProfile` |
| Functions | lowercase_with_underscores | `get_user_data()` |
| Constants | UPPERCASE_WITH_UNDERSCORES | `MAX_CONNECTIONS` |
| Variables | lowercase_with_underscores | `user_count` |
| Django Models | PascalCase (singular) | `Box`, `UserProfile` |
| Django Apps | lowercase (short) | `boxes`, `users` |

### Django-Specific Conventions

**Models:**
```python
from django.db import models

class Box(models.Model):
    """A storage box in the lab."""
    
    name = models.CharField(max_length=255)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name_plural = 'boxes'
        ordering = ['-created_at']

    def __str__(self):
        return self.name
```

**Views:**
```python
from django.shortcuts import render, get_object_or_404
from django.http import Http404

def box_detail(request, box_id):
    """Display details for a specific box."""
    box = get_object_or_404(Box, pk=box_id)
    return render(request, 'boxes/detail.html', {'box': box})
```

### Error Handling

```python
# Use specific exceptions
try:
    result = some_operation()
except SpecificError as exc:
    raise CustomError('Descriptive message') from exc

# Django: Use get_object_or_404 for model lookups
box = get_object_or_404(Box, pk=box_id)

# Log errors appropriately
import logging
logger = logging.getLogger(__name__)
logger.error('Error message: %s', error_detail)
```

### Type Hints (Recommended)

```python
from typing import Optional
from django.http import HttpRequest, HttpResponse

def get_box(request: HttpRequest, box_id: int) -> HttpResponse:
    """Retrieve a box by ID."""
    ...
```

## Project Structure

```
labhelper/
├── .gitea/
│   └── workflows/
│       └── build-containers-on-demand.yml  # CI/CD workflow
├── argocd/                                 # Kubernetes deployment manifests
│   ├── 001_pvc.yaml                        # PersistentVolumeClaim
│   ├── deployment.yaml                     # Deployment + Service
│   ├── ingress.yaml                        # Traefik ingress
│   ├── nfs-pv.yaml                         # NFS PersistentVolume
│   ├── nfs-storageclass.yaml               # NFS StorageClass
│   └── secret.yaml                         # Django secret key template
├── boxes/                                  # Main Django app
│   ├── management/
│   │   └── commands/
│   │       ├── clean_orphaned_files.py     # Cleanup orphaned ThingFile attachments
│   │       └── clean_orphaned_images.py    # Cleanup orphaned Thing images
│   ├── migrations/                         # Database migrations
│   ├── static/
│   │   └── css/
│   │       ├── base.css                    # Base styles (layout, navbar, buttons, alerts, etc.)
│   │       ├── edit_thing.css              # Edit thing form styles
│   │       └── thing_detail.css            # Markdown content + lightbox styles
│   ├── templates/
│   │   └── boxes/
│   │       ├── add_things.html             # Form to add multiple things
│   │       ├── box_detail.html             # Box contents view
│   │       ├── box_management.html         # Box/BoxType CRUD management
│   │       ├── boxes_list.html            # Boxes list page with tabular view
│   │       ├── edit_thing.html            # Edit thing page (name, description, picture, tags, files, links)
│   │       ├── index.html                  # Home page with search and tags
│   │       ├── resources_list.html         # List all links and files from things
│   │       └── thing_detail.html           # Read-only thing details view
│   ├── templatetags/
│   │   └── dict_extras.py                  # Custom template filters: get_item, render_markdown, truncate_markdown
│   ├── admin.py                            # Admin configuration
│   ├── apps.py                             # App configuration
│   ├── forms.py                            # All forms and formsets
│   ├── models.py                           # Data models
│   ├── tests.py                            # Test cases
│   └── views.py                            # View functions
├── data-loader/                            # Init container for database preload
│   ├── Dockerfile                          # Alpine-based init container
│   └── preload.sqlite3                     # Preloaded database for deployment
├── labhelper/                              # Project configuration
│   ├── management/
│   │   └── commands/
│   │       └── create_default_users.py     # Create default users/groups
│   ├── templates/
│   │   ├── base.html                       # Base template with navigation
│   │   └── login.html                      # Login page
│   ├── asgi.py                             # ASGI configuration
│   ├── settings.py                         # Django settings
│   ├── urls.py                             # Root URL configuration
│   └── wsgi.py                             # WSGI configuration
├── scripts/
│   ├── deploy_secret.sh                    # Generate and deploy Django secret
│   ├── full_deploy.sh                      # Bump both container versions + copy DB
│   └── partial_deploy.sh                   # Bump main container version only
├── .gitignore
├── AGENTS.md                               # This file
├── Dockerfile                              # Multi-stage build for main container
├── manage.py                               # Django CLI entry point
└── requirements.txt                        # Python dependencies
```

## Data Models

### boxes app

| Model | Description | Key Fields |
|-------|-------------|------------|
| **BoxType** | Type of storage box with dimensions | `name`, `width`, `height`, `length` (in mm) |
| **Box** | A storage box in the lab | `id` (CharField PK, max 10), `box_type` (FK) |
| **Facet** | A category of tags (e.g., Priority, Category) | `name`, `slug`, `color`, `cardinality` (single/multiple) |
| **Tag** | A tag value for a specific facet | `facet` (FK), `name` |
| **Thing** | An item stored in a box | `name`, `box` (FK), `description` (Markdown), `picture`, `tags` (M2M) |
| **ThingFile** | File attachment for a Thing | `thing` (FK), `file`, `title`, `uploaded_at` |
| **ThingLink** | Hyperlink for a Thing | `thing` (FK), `url`, `title`, `uploaded_at` |

**Model Relationships:**
- BoxType -> Box (1:N via `boxes` related_name, PROTECT on delete)
- Box -> Thing (1:N via `things` related_name, PROTECT on delete)
- Facet -> Tag (1:N via `tags` related_name, CASCADE on delete)
- Thing <-> Tag (M2M via `tags` related_name on Thing, `things` related_name on Tag)
- Thing -> ThingFile (1:N via `files` related_name, CASCADE on delete)
- Thing -> ThingLink (1:N via `links` related_name, CASCADE on delete)

**Facet Cardinality:**
- `single`: A thing can have at most one tag from this facet (e.g., Priority: High/Medium/Low)
- `multiple`: A thing can have multiple tags from this facet (e.g., Category: Electronics, Tools)

## Available Django Extensions

The project includes these pre-installed packages:

- **django-mptt**: Tree structures (categories, hierarchies)
- **django-mptt-admin**: Admin interface for MPTT models
- **django-admin-sortable2**: Drag-and-drop ordering in admin
- **django-nested-admin**: Nested inline forms in admin
- **django-nested-inline**: Additional nested inline support
- **django-revproxy**: Reverse proxy functionality
- **sorl-thumbnail**: Image thumbnailing
- **Pillow**: Image processing
- **gunicorn**: Production WSGI server
- **Markdown**: Markdown processing
- **bleach**: HTML sanitization
- **coverage**: Test coverage
- **Font Awesome**: Icon library (loaded via CDN)
- **jQuery**: JavaScript library (loaded via CDN)

## Frontend/CSS Guidelines

### Base Template

The project uses a base template system at `labhelper/templates/base.html`. All page templates should extend this base:

```django
{% extends "base.html" %}

{% block title %}Page Title - LabHelper{% endblock %}

{% block page_header %}
<!-- Optional page header with breadcrumbs -->
{% endblock %}

{% block content %}
<!-- Main page content -->
{% endblock %}

{% block extra_css %}{% endblock %}
{% block extra_js %}{% endblock %}
```

### Design System

**Color Scheme:**
- Primary gradient: `#667eea` (purple) to `#764ba2` (purple-blue)
- Success: Green gradient
- Error: Red gradient
- Background: Light gray `#f5f5f5` with gradient overlays
- Cards: White with subtle shadows

**Components:**
- **Navigation**: Glassmorphism effect with blur backdrop. Desktop (≥769px) shows horizontal menu with dropdown for authenticated user (contains Box Management, Resources, Admin, Logout)
- **Buttons**: Gradient backgrounds with hover lift effect
- **Cards**: White with rounded corners and box shadows
- **Tables**: Gradient headers with hover row effects
- **Alerts**: Gradient backgrounds with icons
- **Form Inputs**: Focused states with color transitions

**Typography:**
- System fonts: `-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif`
- Headings: Bold, colored
- Body: Regular, dark gray

**Icons:**
- Font Awesome 6.5.1 (CDN)
- Use semantic icons for actions
- Color: Match context or inherit from parent

**Responsive Design:**
- Mobile-first approach
- Grid layouts with `repeat(auto-fill, minmax(250px, 1fr))`
- Flexbox for component layouts
- Breakpoints handled by grid and flex-wrap
- **Navigation**: Responsive navbar with hamburger menu on mobile (≤768px) and horizontal menu with user dropdown on desktop (≥769px). Mobile keeps all items in the dropdown list

### CSS Guidelines

**Static CSS Files:**
- Base styles live in `boxes/static/css/base.css` (loaded by `base.html` via `{% static %}`)
- Page-specific styles live in separate static CSS files (e.g., `thing_detail.css`, `edit_thing.css`)
- Child templates load their CSS via `{% block extra_css %}` with `<link>` tags
- WhiteNoise serves and cache-busts static files via `CompressedManifestStaticFilesStorage`
- Run `python manage.py collectstatic` after adding or modifying static CSS files

**Naming:**
- Use descriptive class names
- BEM pattern encouraged for complex components
- Inline styles allowed for template-specific one-off styling

**Styles:**
- Use base CSS classes when possible
- Page-specific styles in dedicated static CSS files loaded via `{% block extra_css %}`
- JavaScript in `{% block extra_js %}`
- Smooth transitions (0.2s - 0.3s)
- Hover effects with transform and box-shadow

**jQuery Usage:**
- Loaded in base template
- Use for interactive elements (toggles, hovers)
- Event delegation for dynamically added elements
- Focus/blur events for form inputs

### Available Pages/Views

| View Function | URL Pattern | Name | Description |
|---------------|-------------|------|-------------|
| `index` | `/` | `index` | Home page with search and tags overview |
| `boxes_list` | `/search/` | `search`, `boxes_list` | Boxes list page with tabular view |
| `box_management` | `/box-management/` | `box_management` | Manage boxes and box types |
| `add_box_type` | `/box-type/add/` | `add_box_type` | Add new box type |
| `edit_box_type` | `/box-type/<int:type_id>/edit/` | `edit_box_type` | Edit box type |
| `delete_box_type` | `/box-type/<int:type_id>/delete/` | `delete_box_type` | Delete box type |
| `add_box` | `/box/add/` | `add_box` | Add new box |
| `edit_box` | `/box/<str:box_id>/edit/` | `edit_box` | Edit box |
| `delete_box` | `/box/<str:box_id>/delete/` | `delete_box` | Delete box |
| `box_detail` | `/box/<str:box_id>/` | `box_detail` | View box contents |
| `thing_detail` | `/thing/<int:thing_id>/` | `thing_detail` | Read-only view of thing details |
| `edit_thing` | `/thing/<int:thing_id>/edit/` | `edit_thing` | Edit thing (name, description, picture, tags, files, links, move) |
| `add_things` | `/box/<str:box_id>/add/` | `add_things` | Add multiple things to a box |
| `search_api` | `/search/api/` | `search_api` | AJAX search endpoint |
| `resources_list` | `/resources/` | `resources_list` | List all links and files from things (sorted by thing name) |
| `LoginView` | `/login/` | `login` | Django auth login |
| `LogoutView` | `/logout/` | `logout` | Django auth logout |
| `admin.site` | `/admin/` | - | Django admin |

**All views except login require authentication via `@login_required`.**

### Template Best Practices

1. **Always extend base template**
    ```django
    {% extends "base.html" %}
    ```

2. **Use block system for content injection**
    - `title`: Page title tag
    - `page_header`: Page header with breadcrumbs
    - `content`: Main page content
    - `extra_css`: Additional CSS via `<link>` tags to static files
    - `extra_head`: Additional head elements
    - `extra_js`: Additional JavaScript

3. **Load required template tags**
    ```django
    {% load static %}      {# Required when using {% static %} for CSS/asset links #}
    {% load mptt_tags %}
    {% load thumbnail %}
    {% load dict_extras %}
    ```

4. **Link page-specific CSS from static files**
    ```django
    {% block extra_css %}
    <link rel="stylesheet" href="{% static 'css/thing_detail.css' %}">
    {% endblock %}
    ```

5. **Use URL names for links**
    ```django
    <a href="{% url 'box_detail' box.id %}">
    ```

6. **Use icons with Font Awesome**
    ```django
    <i class="fas fa-box"></i>
    ```

7. **Add breadcrumbs for navigation**
    ```django
    <p class="breadcrumb">
        <a href="/"><i class="fas fa-home"></i> Home</a> /
        <a href="/box/{{ box.id }}/"><i class="fas fa-box"></i> Box {{ box.id }}</a>
    </p>
    ```

8. **Icon alignment in lists**: When using icons in list items, use fixed width containers to ensure proper alignment
    ```django
    <a href="{% url 'thing_detail' thing.id %}" style="display: inline-block; width: 20px; text-align: center;">
        <i class="fas fa-link"></i>
    </a>
    ```

### Markdown Support

The `Thing.description` field supports Markdown formatting with HTML sanitization for security.

**Available Template Filters:**

- `render_markdown`: Converts Markdown text to sanitized HTML with automatic link handling
  - Converts Markdown syntax (headers, lists, bold, italic, links, code, tables, etc.)
  - Sanitizes HTML using `bleach` to prevent XSS attacks
  - Automatically adds `target="_blank"` and `rel="noopener noreferrer"` to external links
  - Use in `thing_detail.html` for full rendered Markdown

- `truncate_markdown`: Converts Markdown to plain text and truncates
  - Strips HTML tags after Markdown conversion
  - Adds ellipsis (`...`) if text exceeds specified length (default: 100)
  - Use in `box_detail.html` or search API previews where space is limited

**Usage Examples:**
```django
<!-- Full Markdown rendering -->
<div class="markdown-content">
    {{ thing.description|render_markdown }}
</div>

<!-- Truncated plain text preview -->
{{ thing.description|truncate_markdown:100 }}
```

**Supported Markdown Features:**
- Bold: `**text**` or `__text__`
- Italic: `*text*` or `_text_`
- Headers: `# Header 1`, `## Header 2`, etc.
- Lists: `- item` or `1. item`
- Links: `[text](url)`
- Code: `` `code` `` or ` ```code block``` 
- Blockquotes: `> quote`
- Tables: `| A | B |\n|---|---|`

**Security:**
- All Markdown is sanitized before rendering
- Dangerous HTML tags (`<script>`, `<iframe>`, etc.) are stripped
- Only safe HTML tags and attributes are allowed
- External links automatically get `target="_blank"` and security attributes

## Forms

| Form | Model | Purpose |
|------|-------|---------|
| `ThingForm` | Thing | Add/edit a thing (name, description, picture) - tags managed separately |
| `ThingPictureForm` | Thing | Upload/change thing picture only |
| `ThingFileForm` | ThingFile | Add file attachment |
| `ThingLinkForm` | ThingLink | Add link |
| `BoxTypeForm` | BoxType | Add/edit box type |
| `BoxForm` | Box | Add/edit box |
| `ThingFormSet` | Thing | Formset for adding multiple things |

## Management Commands

### boxes app

| Command | Description | Options |
|---------|-------------|---------|
| `clean_orphaned_files` | Clean up orphaned files from deleted things | `--dry-run` |
| `clean_orphaned_images` | Clean up orphaned images and thumbnails | `--dry-run` |

### labhelper project

| Command | Description |
|---------|-------------|
| `create_default_users` | Create default users and groups (admin/admin123, staff/staff123, viewer/viewer123) |

## Testing Guidelines

- Use `django.test.TestCase` for database tests
- Use `django.test.SimpleTestCase` for tests without database
- Name test files `test_*.py` or `*_tests.py`
- Name test methods `test_*`
- Use descriptive test method names

```python
from django.test import TestCase
from .models import Box

class BoxModelTests(TestCase):
    """Tests for the Box model."""

    def setUp(self):
        """Set up test fixtures."""
        self.box = Box.objects.create(name='Test Box')

    def test_box_str_returns_name(self):
        """Box __str__ should return the box name."""
        self.assertEqual(str(self.box), 'Test Box')
```

## Files to Never Commit

Per `.gitignore`:
- `__pycache__/`, `*.pyc` - Python bytecode
- `.venv/` - Virtual environment
- `.env` - Environment variables
- `data/db.sqlite3` - Database file
- `keys/` - Secret keys

## Common Pitfalls

1. **NEVER commit or push without explicit permission**: Always ask the user before running `git commit` or `git push`. The user will explicitly say "commit and push" when they want you to do this. Do NOT automatically commit/push after making changes unless instructed to do so.
2. **Always activate venv**: `source .venv/bin/activate`
3. **Run migrations after model changes**: `makemigrations` then `migrate`
4. **Add new apps to INSTALLED_APPS** in `settings.py`
5. **Templates in labhelper/templates/**: The base template and shared templates are in `labhelper/templates/`. App-specific templates remain in `app_name/templates/`.
6. **Use get_object_or_404** instead of bare `.get()` calls
7. **Never commit SECRET_KEY** - use environment variables in production
8. **Be careful with process management**: Avoid blanket kills on ports (e.g., `lsof -ti:8000 | xargs kill -9`) as they can kill unintended processes like web browsers. Use specific process kills instead: `pkill -f "process_name"`

## Deployment Commands

### Prepare a Full Deployment

When instructed to "Prepare a full deployment", perform the following steps:

1. **Bump container versions**: In `argocd/deployment.yaml`, increment the version numbers by 0.001 for both containers:
   - `labhelper-data-loader` (initContainer)
   - `labhelper` (main container)

2. **Copy database**: Copy the current development database to the data-loader preload location:
   ```bash
   cp data/db.sqlite3 data-loader/preload.sqlite3
   ```

### Prepare a Partial Deployment

When instructed to "Prepare a partial deployment", perform the following step:

1. **Bump main container version only**: In `argocd/deployment.yaml`, increment the version number by 0.001 for the main container only:
   - `labhelper` (main container)

Do NOT bump the data-loader version or copy the database.