siderust-py 0.2.1

//! Observer / observatory type for Python.
//!
//! Wraps `Geodetic<ECEF>` as a Python class with named constructors for
//! major observatory sites.

use pyo3::prelude::*;
use siderust::coordinates::centers::Geodetic;
use siderust::coordinates::frames::ECEF;
use siderust::qtty::{Degrees, Meters};

/// An observer location on the Earth's surface (WGS84 geodetic).
///
/// Create from longitude/latitude/height or use a predefined observatory.
///
/// Example:
/// >>> obs = Observer(-17.8925, 28.7543, 2396.0)       # custom
/// >>> obs = Observer.roque_de_los_muchachos()           # catalog
#[pyclass(name = "Observer", module = "siderust", from_py_object)]
#[derive(Clone)]
pub struct PyObserver {
    pub(crate) inner: Geodetic<ECEF>,
}

impl PyObserver {
    pub fn from_inner(inner: Geodetic<ECEF>) -> Self {
        Self { inner }
    }
}

#[pyfunction]
pub(crate) fn _bridge_observer_to_parts(value: &Bound<'_, PyAny>) -> PyResult<(f64, f64, f64)> {
    let observer = value.cast::<PyObserver>()?.borrow();
    Ok((
        observer.inner.lon.value(),
        observer.inner.lat.value(),
        observer.inner.height.value(),
    ))
}

#[pyfunction]
pub(crate) fn _bridge_observer_from_parts(
    longitude_degrees: f64,
    latitude_degrees: f64,
    height_metres: f64,
) -> PyObserver {
    PyObserver::new(longitude_degrees, latitude_degrees, height_metres)
}

#[pymethods]
impl PyObserver {
    /// Create a custom observer at a geodetic position.
    ///
    /// Args:
    ///     lon_deg: Longitude in degrees (east positive).
    ///     lat_deg: Latitude in degrees (north positive).
    ///     height_m: Height above ellipsoid in metres (default 0).
    #[new]
    #[pyo3(signature = (lon_deg, lat_deg, height_m = 0.0))]
    fn new(lon_deg: f64, lat_deg: f64, height_m: f64) -> Self {
        Self {
            inner: Geodetic::<ECEF>::new(
                Degrees::new(lon_deg),
                Degrees::new(lat_deg),
                Meters::new(height_m),
            ),
        }
    }

    // ── Predefined observatories ──────────────────────────────────────

    /// Roque de los Muchachos Observatory (La Palma, Spain).
    #[staticmethod]
    fn roque_de_los_muchachos() -> Self {
        Self {
            inner: siderust::catalogs::observatories::ROQUE_DE_LOS_MUCHACHOS.geodetic,
        }
    }

    /// El Paranal Observatory (Chile).
    #[staticmethod]
    fn el_paranal() -> Self {
        Self {
            inner: siderust::catalogs::observatories::EL_PARANAL.geodetic,
        }
    }

    /// Mauna Kea Observatory (Hawaiʻi, USA).
    #[staticmethod]
    fn mauna_kea() -> Self {
        Self {
            inner: siderust::catalogs::observatories::MAUNA_KEA.geodetic,
        }
    }

    /// La Silla Observatory (Chile).
    #[staticmethod]
    fn la_silla() -> Self {
        Self {
            inner: siderust::catalogs::observatories::LA_SILLA_OBSERVATORY.geodetic,
        }
    }

    // ── Properties ────────────────────────────────────────────────────

    /// Longitude in degrees.
    #[getter]
    fn lon_deg(&self) -> f64 {
        self.inner.lon.value()
    }

    /// Latitude in degrees.
    #[getter]
    fn lat_deg(&self) -> f64 {
        self.inner.lat.value()
    }

    /// Height above ellipsoid in metres.
    #[getter]
    fn height_m(&self) -> f64 {
        self.inner.height.value()
    }

    fn __repr__(&self) -> String {
        format!(
            "Observer(lon={:.4}°, lat={:.4}°, h={:.1}m)",
            self.inner.lon.value(),
            self.inner.lat.value(),
            self.inner.height.value()
        )
    }

    fn __str__(&self) -> String {
        self.__repr__()
    }

    fn __eq__(&self, other: &PyObserver) -> bool {
        (self.inner.lon.value() - other.inner.lon.value()).abs() < 1e-10
            && (self.inner.lat.value() - other.inner.lat.value()).abs() < 1e-10
            && (self.inner.height.value() - other.inner.height.value()).abs() < 1e-6
    }

    fn __hash__(&self) -> u64 {
        use std::collections::hash_map::DefaultHasher;
        use std::hash::{Hash, Hasher};
        let mut hasher = DefaultHasher::new();
        self.inner.lon.value().to_bits().hash(&mut hasher);
        self.inner.lat.value().to_bits().hash(&mut hasher);
        self.inner.height.value().to_bits().hash(&mut hasher);
        hasher.finish()
    }

    fn __reduce__(&self, py: Python<'_>) -> PyResult<(Py<PyAny>, (f64, f64, f64))> {
        let cls = py.get_type::<Self>().into_any().unbind();
        Ok((
            cls,
            (
                self.inner.lon.value(),
                self.inner.lat.value(),
                self.inner.height.value(),
            ),
        ))
    }

    /// Convert to a dictionary.
    fn to_dict<'py>(&self, py: Python<'py>) -> PyResult<Bound<'py, pyo3::types::PyDict>> {
        let d = pyo3::types::PyDict::new(py);
        d.set_item("lon_deg", self.lon_deg())?;
        d.set_item("lat_deg", self.lat_deg())?;
        d.set_item("height_m", self.height_m())?;
        Ok(d)
    }

    /// Create from a dictionary.
    #[staticmethod]
    fn from_dict(d: &Bound<'_, pyo3::types::PyDict>) -> PyResult<Self> {
        let get = |k: &str| -> PyResult<f64> {
            d.get_item(k)?
                .ok_or_else(|| {
                    pyo3::exceptions::PyValueError::new_err(format!("missing key '{}'", k))
                })?
                .extract()
        };
        Ok(Self::new(
            get("lon_deg")?,
            get("lat_deg")?,
            get("height_m")?,
        ))
    }
}