From 8247f7d7e1fe30debf738435b3cdccdd15c24e2f Mon Sep 17 00:00:00 2001
From: Daniel Schadt <kingdread@gmx.de>
Date: Wed, 9 Jul 2025 19:48:43 +0200
Subject: first working Python interface

---
 hittekaart-py/src/lib.rs | 155 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 155 insertions(+)
 create mode 100644 hittekaart-py/src/lib.rs

(limited to 'hittekaart-py/src')

diff --git a/hittekaart-py/src/lib.rs b/hittekaart-py/src/lib.rs
new file mode 100644
index 0000000..9f4bd8d
--- /dev/null
+++ b/hittekaart-py/src/lib.rs
@@ -0,0 +1,155 @@
+use hittekaart::gpx::{self, Compression, Coordinates};
+use hittekaart::renderer::{self, Renderer};
+use pyo3::create_exception;
+use pyo3::exceptions::PyTypeError;
+use pyo3::prelude::*;
+use std::error::Error;
+use std::ffi::OsStr;
+use std::fmt::Write as _;
+use std::os::unix::ffi::OsStrExt as _;
+
+create_exception!(hittekaart_py, HitteError, pyo3::exceptions::PyException);
+
+fn err_to_py(mut error: &dyn Error) -> PyErr {
+    let mut text = error.to_string();
+    loop {
+        match error.source() {
+            None => break,
+            Some(e) => error = e,
+        }
+        write!(&mut text, "\ncaused by: {error}").unwrap();
+    }
+    HitteError::new_err(text)
+}
+
+#[pyclass]
+#[derive(Debug, Clone)]
+struct Track {
+    inner: Vec<Coordinates>,
+}
+
+#[pymethods]
+impl Track {
+    #[staticmethod]
+    fn from_file(path: &[u8], compression: Option<&str>) -> PyResult<Track> {
+        let compression = match compression {
+            None | Some("") => Compression::None,
+            Some("gzip") => Compression::Gzip,
+            Some("brotli") => Compression::Brotli,
+            Some(x) => return Err(HitteError::new_err(format!("invalid compression: {x}"))),
+        };
+        let track = gpx::extract_from_file(OsStr::from_bytes(path), compression)
+            .map_err(|e| err_to_py(&e))?;
+        Ok(Track { inner: track })
+    }
+
+    #[staticmethod]
+    fn from_coordinates(coordinates: Vec<(f64, f64)>) -> Track {
+        Track {
+            inner: coordinates
+                .iter()
+                .map(|(lon, lat)| Coordinates::new(*lon, *lat))
+                .collect(),
+        }
+    }
+
+    fn coordinates(&self) -> Vec<(f64, f64)> {
+        self.inner
+            .iter()
+            .map(|c| (c.longitude, c.latitude))
+            .collect()
+    }
+}
+
+#[pyclass]
+struct Storage {
+    inner: Box<dyn hittekaart::storage::Storage + Send + Sync>,
+}
+
+#[pymethods]
+impl Storage {
+    #[staticmethod]
+    #[pyo3(name = "Folder")]
+    fn folder(path: &[u8]) -> Self {
+        let path = OsStr::from_bytes(path);
+        let storage = hittekaart::storage::Folder::new(path.into());
+        Storage {
+            inner: Box::new(storage),
+        }
+    }
+}
+
+#[pyclass]
+struct HeatmapRenderer {
+    inner: renderer::heatmap::Renderer,
+}
+
+#[pymethods]
+impl HeatmapRenderer {
+    #[new]
+    fn new() -> HeatmapRenderer {
+        HeatmapRenderer {
+            inner: renderer::heatmap::Renderer,
+        }
+    }
+}
+
+#[pyfunction]
+fn generate(
+    items: &Bound<'_, PyAny>,
+    renderer: &Bound<'_, PyAny>,
+    storage: &Bound<'_, Storage>,
+) -> PyResult<()> {
+    let mut tracks = vec![];
+
+    for item in items.try_iter()? {
+        let item = item?;
+        tracks.push(item.extract::<Track>()?.inner);
+    }
+
+    if let Ok(r) = renderer.downcast::<HeatmapRenderer>() {
+        do_generate(tracks, &r.borrow().inner, &mut storage.borrow_mut())
+    } else {
+        Err(PyTypeError::new_err("Expected a HeatmapRenderer"))
+    }
+}
+
+fn do_generate<R: Renderer>(
+    tracks: Vec<Vec<Coordinates>>,
+    renderer: &R,
+    storage: &mut Storage,
+) -> PyResult<()> {
+    storage.inner.prepare().map_err(|e| err_to_py(&e))?;
+
+    for zoom in 0..=19 {
+        let counter =
+            renderer::prepare(renderer, zoom, &tracks, || Ok(())).map_err(|e| err_to_py(&e))?;
+
+        storage
+            .inner
+            .prepare_zoom(zoom)
+            .map_err(|e| err_to_py(&e))?;
+
+        renderer::colorize(renderer, counter, |rendered_tile| {
+            storage
+                .inner
+                .store(zoom, rendered_tile.x, rendered_tile.y, &rendered_tile.data)?;
+            Ok(())
+        })
+        .map_err(|e| err_to_py(&e))?;
+    }
+    storage.inner.finish().map_err(|e| err_to_py(&e))?;
+
+    Ok(())
+}
+
+/// A Python module implemented in Rust.
+#[pymodule]
+fn hittekaart_py(py: Python<'_>, m: &Bound<'_, PyModule>) -> PyResult<()> {
+    m.add_class::<Track>()?;
+    m.add_class::<HeatmapRenderer>()?;
+    m.add_class::<Storage>()?;
+    m.add_function(wrap_pyfunction!(generate, m)?)?;
+    m.add("HitteError", py.get_type::<HitteError>())?;
+    Ok(())
+}
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