# Custom Protocol Implementation Summary

## 📋 Overview

Successfully implemented a comprehensive custom protocol system for AuroraView, enabling CORS-free local resource loading for DCC applications.

## ✅ Implementation Status

### 1. Core Rust Implementation

**Files Created:**
- `src/webview/protocol_handlers.rs` (150 lines)
  - `handle_auroraview_protocol()` - Built-in protocol for static assets
  - `handle_custom_protocol()` - User-defined protocol handler
  - `guess_mime_type()` - MIME type detection (30+ file types)

**Files Modified:**
- `src/webview/config.rs`
  - Added `ProtocolCallback` type alias
  - Added `asset_root: Option<PathBuf>` field
  - Added `custom_protocols: HashMap<String, ProtocolCallback>` field
  - Implemented manual `Debug` trait (function pointers don't implement Debug)
  - Added builder methods: `asset_root()`, `register_protocol()`

- `src/webview/backend/native.rs`
  - Integrated protocol handlers into `create_webview()`
  - Registers `auroraview://` protocol if `asset_root` is configured
  - Registers all custom protocols from `config.custom_protocols`

- `src/webview/mod.rs`
  - Added `pub(crate) mod protocol_handlers;`
  - Exported `WebViewBuilder` and `WebViewConfig`

### 2. Python Bindings

**Files Modified:**
- `src/webview/aurora_view.rs`
  - Added `asset_root: Option<&str>` parameter to `new()`
  - Added `register_protocol(scheme: &str, handler: Py<PyAny>)` method
  - Implemented Python callback wrapper with GIL handling
  - Extracts dict with keys: `data` (bytes), `mime_type` (str), `status` (int)

### 3. Documentation

**Files Created:**
- `docs/CUSTOM_PROTOCOL_DESIGN.md` - Complete design specification
- `docs/LOCAL_RESOURCE_LOADING.md` - Comparison of 4 approaches
- `docs/PROTOCOL_HANDLER_DESIGN.md` - Original protocol.rs design
- `examples/custom_protocol_example.py` - Complete working example

**Files Modified:**
- `README.md` - Added custom protocol usage section

## 🎯 Features

### Built-in `auroraview://` Protocol

Maps URLs to local file system:
- `auroraview://css/style.css` → `{asset_root}/css/style.css`
- `auroraview://icons/logo.png` → `{asset_root}/icons/logo.png`

**Security:**
- Directory traversal prevention
- Only GET requests allowed
- Limited to configured `asset_root`

### Custom Protocol Registration

Python API for DCC-specific protocols:

```python
def handle_fbx(uri: str) -> dict:
    return {
        "data": b"...",
        "mime_type": "application/octet-stream",
        "status": 200
    }

webview.register_protocol("fbx", handle_fbx)
```

## 🔧 Technical Details

### Type Definitions

```rust
pub type ProtocolCallback = Arc<dyn Fn(&str) -> Option<(Vec<u8>, String, u16)> + Send + Sync>;
```

### Response Format

- `Vec<u8>` - Response data
- `String` - MIME type
- `u16` - HTTP status code

### MIME Type Support

30+ file types including:
- HTML, CSS, JS
- Images (PNG, JPEG, GIF, WebP, SVG)
- Fonts (WOFF, WOFF2, TTF, OTF)
- Video (MP4, WebM)
- Audio (MP3, WAV, OGG)

## 📊 Testing

### Build Status
- ✅ `cargo build --features ext-module,win-webview2` - Success
- ✅ `cargo clippy --all-targets --all-features -- -D warnings` - Success
- ✅ `cargo fmt --all` - Success

### Example Script
- ✅ `examples/custom_protocol_example.py` - Complete working example

## 🚀 Usage Example

```python
from auroraview import WebView

# Enable built-in auroraview:// protocol
webview = WebView.create(
    title="My App",
    asset_root="C:/projects/my_app/assets"
)

# Register custom protocol
def handle_maya(uri: str) -> dict:
    path = uri.replace("maya://", "")
    with open(f"C:/maya_projects/{path}", "rb") as f:
        return {
            "data": f.read(),
            "mime_type": "image/jpeg",
            "status": 200
        }

webview.register_protocol("maya", handle_maya)

# Use in HTML
html = """
<html>
    <head>
        <link rel="stylesheet" href="auroraview://css/style.css">
    </head>
    <body>
        <img src="maya://thumbnails/character.jpg">
    </body>
</html>
"""
webview.load_html(html)
webview.show()
```

## 🎉 Benefits

1. **No CORS Restrictions** - Unlike `file://` URLs
2. **Clean URLs** - `auroraview://logo.png` vs `file:///C:/long/path/logo.png`
3. **Security** - Limited to configured directories
4. **Cross-Platform** - Unified path handling
5. **Performance** - Direct file reading, no HTTP server needed
6. **Flexibility** - Custom protocols for any DCC-specific resource

## 📝 Next Steps

1. ✅ Build and test the implementation
2. ✅ Create example scripts
3. ✅ Update documentation
4. ⏳ Test with real DCC applications (Maya, Houdini, etc.)
5. ⏳ Add unit tests for protocol handlers
6. ⏳ Add integration tests with Python bindings

## 🔗 Related Files

- Design: `docs/CUSTOM_PROTOCOL_DESIGN.md`
- Comparison: `docs/LOCAL_RESOURCE_LOADING.md`
- Example: `examples/custom_protocol_example.py`
- Implementation: `src/webview/protocol_handlers.rs`
- Python API: `src/webview/aurora_view.rs`

