# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

BackSafe is a cross-platform desktop application for backing up data from mobile phones (primarily Android, with photos/videos support on iOS/iPadOS) using a user-provided API key. Built with Avalonia UI and .NET 8, targeting Windows, macOS, and Linux.

## Development Commands

### Build and Run
```bash
dotnet build                    # Build the project
dotnet run                      # Run the application
dotnet build -c Release         # Build for release
```

### Debugging
- Avalonia diagnostics are enabled in Debug builds only (BackSafe.csproj:22-25)
- Use F12 or Ctrl+F12 within the running application to access DevTools in Debug mode

## Architecture

### UI Framework: Avalonia UI
- Uses AXAML (Avalonia XAML) for UI definitions
- Fluent theme is the default (App.axaml:13)
- Compiled bindings enabled by default (BackSafe.csproj:8)

### MVVM Pattern
- **ViewModels**: Inherit from `ViewModelBase` (extends `ObservableObject` from CommunityToolkit.Mvvm)
- **Views**: Located in `Views/` directory, defined with `.axaml` files and code-behind `.axaml.cs`
- **ViewLocator**: Automatically maps ViewModels to Views by naming convention (ViewModel → View)
  - Example: `MainWindowViewModel` → `MainWindow`
  - Implementation in ViewLocator.cs:16

### Application Entry Point
- `Program.cs`: Standard .NET entry point
  - Configures Avalonia with platform detection, Inter font, and trace logging
- `App.axaml.cs`: Avalonia initialization
  - Disables Avalonia's DataAnnotation validation to avoid conflicts with CommunityToolkit (App.axaml.cs:35-46)
  - Sets MainWindow with MainWindowViewModel as DataContext

### Key Dependencies
- **Avalonia 11.3.6**: Cross-platform UI framework
- **CommunityToolkit.Mvvm 8.2.1**: MVVM helpers (ObservableObject, commands, etc.)
- **Avalonia.Fonts.Inter**: Default font package

### Project Structure
- `ViewModels/`: Contains all ViewModel classes
- `Views/`: Contains AXAML view definitions and code-behind
- `Models/`: Placeholder directory for data models
- `Assets/`: Application resources (icons, etc.)
- `app.manifest`: Windows application manifest

## MVVM Conventions
- ViewModels use partial classes to support MVVM Toolkit source generators
- Properties in ViewModels should use `[ObservableProperty]` attribute for automatic INotifyPropertyChanged implementation
- Views use `x:DataType` for compiled bindings (see MainWindow.axaml:8)