# Complete Python Bindings for Nigiri - Project Summary

## 🎉 Project Complete!

I have created comprehensive Python bindings for the nigiri C++ transit routing library. The bindings expose all major functionality through a clean, Pythonic API with a simple integer-based time system.

### ✅ Current Status (January 2026)
- **All 23 unit tests passing** ✅
- **Clean integer-based time API** ✅ (all times as minutes since epoch)
- **Routing verified working** ✅ (successfully finds routes with test GTFS data)
- **Examples validated** ✅ (all using integer API)
- **pytest configured** ✅ (excludes C++ dependencies from discovery)
- **Production ready** ✅

## 📁 Project Structure

```
python/
├── src/                          # C++ binding source code
│   ├── main.cc                   # Module entry point
│   ├── types.cc                  # Core types and structures
│   ├── timetable.cc              # Timetable data access
│   ├── loader.cc                 # Data loading
│   ├── routing.cc                # Routing algorithms
│   ├── rt.cc                     # Real-time updates
│   └── pybind_common.h           # Common headers
│
├── pynigiri/                     # Python package
│   └── __init__.py               # Package exports
│
├── examples/                     # Usage examples
│   ├── basic_routing.py          # Simple routing
│   ├── realtime_updates.py       # GTFS-RT updates
│   ├── advanced_routing.py       # Advanced features
│   └── explore_timetable.py      # Data exploration
│
├── tests/                        # Unit tests
│   ├── test_types.py             # Type tests
│   ├── test_loader.py            # Loader tests
│   ├── test_routing.py           # Routing tests
│   ├── test_rt.py                # RT tests
│   └── README.md                 # Test documentation
│
├── CMakeLists.txt                # Build configuration
├── pyproject.toml                # Python packaging
├── setup.py                      # Build script
├── README.md                     # Quick start guide
├── INSTALL.md                    # Installation guide
├── API.md                        # API reference
├── SUMMARY.md                    # Feature overview
├── LICENSE                       # MIT license
├── MANIFEST.in                   # Package manifest
├── .gitignore                    # Git ignore rules
├── build.sh                      # Linux/Mac build script
└── build.bat                     # Windows build script
```

## 🚀 Key Features

### ✅ Complete API Coverage

1. **Core Types** (`types.cc`)
   - Location indices and identifiers
   - Time and duration types
   - Footpaths and intervals
   - Enumerations (transport classes, location types, etc.)

2. **Timetable Access** (`timetable.cc`)
   - Location queries by ID
   - Location metadata (names, coordinates, types)
   - Route and transport information
   - Date range queries

3. **Data Loading** (`loader.cc`)
   - GTFS, HRD, and NetEx support
   - Configurable loading options
   - Footpath generation
   - Multiple data sources
   - Duplicate merging

4. **Routing** (`routing.cc`)
   - RAPTOR algorithm implementation
   - Multi-criteria optimization
   - Via stops with minimum stay
   - Time intervals
   - Multiple start/destination points
   - Transport class filtering
   - Bike/car transport requirements
   - Customizable transfer times

5. **Real-Time Updates** (`rt.cc`)
   - GTFS-RT trip updates
   - Service alerts
   - Vehicle positions
   - Update from files/bytes/strings
   - Detailed statistics

## 📚 Documentation

- **README.md**: Quick start and basic examples
- **INSTALL.md**: Detailed installation for all platforms
- **API.md**: Complete API reference with examples
- **SUMMARY.md**: Feature overview and architecture

## 🧪 Testing

- Comprehensive unit tests for all components
- Example-based integration tests
- Ready for CI/CD integration

## 🔨 Build System

- Modern CMake configuration
- Python packaging with pyproject.toml
- scikit-build-core for cross-platform builds
- Automatic pybind11 fetching
- Platform-specific build scripts

## 🧪 Testing & Validation

### Test Suite
- **23 unit tests** - All passing ✅
- `pytest.ini` configured to exclude C++ dependencies
- Tests cover: types, loading, routing, real-time updates
- Run with: `pytest tests/`

### Examples Verified
- ✅ `basic_routing.py` - Successfully finds routes in test data
- ✅ `advanced_routing.py` - All 5 advanced examples working
- ✅ `explore_timetable.py` - Timetable exploration functional
- All examples use current year (2026) and correct API patterns

## ⚠️ API Design

### Integer-Based Time API

PyNigiri uses a clean, explicit integer-based time API:

- **All times are integers**: Minutes since Unix epoch (1970-01-01 00:00:00 UTC)
- **All durations are integers**: Number of minutes
- **Simple and explicit**: No automatic conversions that could cause bugs

**Converting Between Python datetime and Integers**:
```python
from datetime import datetime

# Python datetime → Integer (minutes since epoch)
dt = datetime(2026, 1, 15, 10, 0, 0)
minutes = int(dt.timestamp()) // 60

# Integer → Python datetime
dt = datetime.fromtimestamp(minutes * 60)
```

**Benefits**:
- ✅ Simple and explicit
- ✅ No datetime conversion bugs
- ✅ Efficient integer operations
- ✅ Clear API semantics

## 💡 Usage Example

```python
import pynigiri as ng
from datetime import datetime, date

# Load timetable - use current year for your GTFS data
current_year = date.today().year
sources = [ng.TimetableSource("gtfs", "/path/to/gtfs")]
tt = ng.load_timetable(sources, f"{current_year}-01-01", f"{current_year}-12-31")

# Create routing query
query = ng.Query()

# Convert datetime to minutes since epoch
query_time = datetime(current_year, 1, 15, 10, 0, 0)
query.start_time = int(query_time.timestamp()) // 60

# All durations and offsets are integers (minutes)
query.start = [ng.Offset(start_loc, 0, 0)]  # 0 minutes offset
query.destination = [ng.Offset(dest_loc, 0, 0)]
query.max_transfers = 6
query.max_travel_time = 600  # 10 hours in minutes
query.start_match_mode = ng.LocationMatchMode.EQUIVALENT
query.dest_match_mode = ng.LocationMatchMode.EQUIVALENT

# Execute routing
journeys = ng.route(tt, query)

# Process results - all times are integers (minutes since epoch)
for journey in journeys:
    print(f"Travel time: {journey.travel_time()} min")
    print(f"Transfers: {journey.transfers}")
    
    for leg in journey.legs:
        # Use getattr for 'from' (Python keyword)
        from_loc = getattr(leg, 'from')
        from_name = tt.get_location_name(from_loc)
        to_name = tt.get_location_name(leg.to)
        
        # Convert integer times to datetime for display
        dep_dt = datetime.fromtimestamp(leg.dep_time * 60)
        arr_dt = datetime.fromtimestamp(leg.arr_time * 60)
        
        print(f"  {from_name} -> {to_name}")
        print(f"    {dep_dt.strftime('%H:%M')} -> {arr_dt.strftime('%H:%M')}")
```

## 📦 Installation

### Quick Install
```bash
cd nigiri/python
pip install .
```

### Development Mode
```bash
pip install -e .
```

### Using Build Scripts
```bash
# Linux/Mac
./build.sh

# Windows
build.bat
```

## 🎯 What's Bound

### Data Structures
- ✅ Strong types (LocationIdx, RouteIdx, etc.)
- ✅ Duration and time types
- ✅ Geographic coordinates
- ✅ Footpaths
- ✅ Time intervals
- ✅ All enumerations

### Timetable
- ✅ Location lookup and information
- ✅ Coordinate access
- ✅ Hierarchy navigation
- ✅ Metadata queries
- ✅ Statistics

### Loading
- ✅ Multiple data source support
- ✅ Configurable options
- ✅ Date range specification
- ✅ Footpath settings
- ✅ Finalization options

### Routing
- ✅ Query configuration
- ✅ Journey planning
- ✅ Via stops
- ✅ Time windows
- ✅ Multi-origin/destination
- ✅ Class filtering
- ✅ Special requirements (bikes, etc.)
- ✅ Journey comparison

### Real-Time
- ✅ RT timetable creation
- ✅ GTFS-RT updates
- ✅ Statistics tracking
- ✅ Multiple input formats

## 🔧 Technical Details

- **Binding Framework**: pybind11 v2.11.1
- **C++ Standard**: C++23
- **Python Version**: 3.8+
- **Build System**: CMake 3.22+ with scikit-build-core
- **License**: MIT

## 🌟 Highlights

1. **Zero-Copy Design**: Efficient data access without unnecessary copying
2. **Pythonic API**: Natural Python interface to C++ functionality
3. **Type Safety**: Strong typing preserved from C++
4. **Performance**: Native C++ speed for routing
5. **Comprehensive**: All major features bound
6. **Well-Documented**: Extensive docs and examples
7. **Tested**: Unit tests for all components
8. **Cross-Platform**: Linux, macOS, Windows support

## 🚦 Next Steps

To use the bindings:

1. **Build**: Run `./build.sh` or `build.bat`
2. **Test**: Run `pytest tests/`
3. **Try Examples**: Run scripts in `examples/`
4. **Read Docs**: Check `API.md` for reference
5. **Integrate**: Use in your projects!

## 📖 Learning Resources

- Start with `examples/basic_routing.py` for simple routing
- See `examples/advanced_routing.py` for complex queries
- Check `examples/realtime_updates.py` for GTFS-RT
- Read `API.md` for complete API documentation
- Run tests to see more usage patterns

## 🤝 Contributing

The binding structure is modular and easy to extend:

1. Add bindings in `src/*.cc` files
2. Update exports in `pynigiri/__init__.py`
3. Add tests in `tests/test_*.py`
4. Add examples in `examples/`
5. Update documentation

## ✨ Summary

The complete Python binding provides:
- **Full functionality** of the nigiri library
- **Clean, Pythonic API** for ease of use
- **High performance** with minimal overhead
- **Comprehensive documentation** and examples
- **Ready for production** use

All major components of the nigiri library are now accessible from Python with a natural, easy-to-use interface!
