1 files changed, 189 insertions, 0 deletions

diff --git a/server/src/gpx.cpp b/server/src/gpx.cpp
new file mode 100644
index 0000000..62dccff
--- /dev/null
+++ b/server/src/gpx.cpp
@@ -0,0 +1,189 @@
+module;
+
+#include <boost/geometry/algorithms/append.hpp>
+
+module routemon:gpx$impl;
+
+import std;
+import :gpx;
+import :util;
+import :xml;
+
+using namespace std::literals::string_view_literals;
+
+namespace routemon::gpx {
+
+  namespace v10 {
+
+    constexpr auto xmlns = "http://www.topografix.com/GPX/1/0"sv;
+    auto qname(std::string_view local) -> xml::qname_view {
+      return {.ns_uri = xmlns, .local = local};
+    }
+
+    auto parse_wpt(xml::executor_ref e, xml::attribute_view attrs) -> xml::parser<geo::point> {
+      auto parse_xml_double = [](std::string_view sv) -> std::optional<double> {
+        return util::parse_double(sv, std::chars_format::fixed);
+      };
+      auto mlat = std::optional<double>{};
+      auto mlon = std::optional<double>{};
+      for (auto const& [name, value] : attrs) {
+        if (name == qname("lat")) {
+          mlat = parse_xml_double(value);
+        } else if (name == qname("lon")) {
+          mlon = parse_xml_double(value);
+        }
+      }
+      if (!mlat || !mlon)
+        throw std::runtime_error{"expected valid latitude and longitude for waypoint"};
+      co_await xml::ignore_contents(e);
+      co_return geo::point{*mlon, *mlat};
+    }
+
+    auto parse_trkseg(xml::executor_ref e, xml::attribute_view) -> xml::parser<track_segment> {
+      auto s = track_segment{};
+      while (auto mwpt = co_await allow_element(e, qname("trkpt"), xml::hohalo<parse_wpt>()))
+        bgeo::append(s.waypoints, *mwpt);
+      co_return std::move(s);
+    }
+
+    auto parse_trk(xml::executor_ref e, xml::attribute_view) -> xml::parser<track> {
+      auto t = track{};
+      t.name = co_await allow_element(e, qname("name"), xml::hohalo<xml::read_string_contents>());
+      co_await allow_element(e, qname("cmt"), xml::hohalo<xml::ignore_element_contents>());
+      t.desc = co_await allow_element(e, qname("desc"), xml::hohalo<xml::read_string_contents>());
+      co_await xml::ignore_contents(e, /* until */ qname("trkseg"));
+      while (auto mseg = co_await allow_element(e, qname("trkseg"), xml::hohalo<parse_trkseg>()))
+        t.segments.push_back(std::move(*mseg));
+      co_return std::move(t);
+    }
+
+    auto parse_gpx(xml::executor_ref e, xml::attribute_view attrs) -> xml::parser<file> {
+      auto f = file{};
+      if (attrs.lookup(qname("version")) != "1.0"sv)
+        throw std::runtime_error{"expected GPX version to be 1.0"};
+      if (auto mcreator = attrs.lookup(qname("creator")))
+        f.creator = *mcreator;
+      else
+        throw std::runtime_error{"expected GPX file to have creator"};
+
+      f.meta.name = co_await allow_element(e, qname("name"), xml::hohalo<xml::read_string_contents>());
+      f.meta.desc = co_await allow_element(e, qname("desc"), xml::hohalo<xml::read_string_contents>());
+
+      co_await xml::ignore_contents(e, /* until */ qname("trk"));
+      while (auto mtrk = co_await allow_element(e, qname("trk"), xml::hohalo<parse_trk>()))
+        f.tracks.push_back(std::move(*mtrk));
+      co_await xml::ignore_contents(e);
+
+      co_return std::move(f);
+    }
+
+  } // namespace v10
+
+  namespace v11 {
+
+    constexpr auto xmlns = "http://www.topografix.com/GPX/1/1"sv;
+    auto qname(std::string_view local) -> xml::qname_view {
+      return {.ns_uri = xmlns, .local = local};
+    }
+
+    auto parse_metadata(xml::executor_ref e, xml::attribute_view) -> xml::parser<metadata> {
+      auto meta = metadata{};
+      meta.name = co_await allow_element(e, qname("name"), xml::hohalo<xml::read_string_contents>());
+      meta.desc = co_await allow_element(e, qname("desc"), xml::hohalo<xml::read_string_contents>());
+      co_await xml::ignore_contents(e);
+      co_return meta;
+    }
+
+    auto parse_wpt(xml::executor_ref e, xml::attribute_view attrs) -> xml::parser<geo::point> {
+      auto parse_xml_double = [](std::string_view sv) -> std::optional<double> {
+        return util::parse_double(sv, std::chars_format::fixed);
+      };
+      auto mlat = std::optional<double>{};
+      auto mlon = std::optional<double>{};
+      for (auto const& [name, value] : attrs) {
+        if (name == qname("lat")) {
+          mlat = parse_xml_double(value);
+        } else if (name == qname("lon")) {
+          mlon = parse_xml_double(value);
+        }
+      }
+      if (!mlat || !mlon)
+        throw std::runtime_error{"expected valid latitude and longitude for waypoint"};
+      co_await xml::ignore_contents(e);
+      co_return geo::point{*mlon, *mlat};
+    }
+
+    auto parse_trkseg(xml::executor_ref e, xml::attribute_view) -> xml::parser<track_segment> {
+      auto s = track_segment{};
+      while (auto mwpt = co_await allow_element(e, qname("trkpt"), xml::hohalo<parse_wpt>()))
+        bgeo::append(s.waypoints, *mwpt);
+      co_await allow_element(e, qname("extensions"), xml::hohalo<xml::ignore_element_contents>());
+      co_return std::move(s);
+    }
+
+    auto parse_trk(xml::executor_ref e, xml::attribute_view) -> xml::parser<track> {
+      auto t = track{};
+      t.name = co_await allow_element(e, qname("name"), xml::hohalo<xml::read_string_contents>());
+      co_await allow_element(e, qname("cmt"), xml::hohalo<xml::ignore_element_contents>());
+      t.desc = co_await allow_element(e, qname("desc"), xml::hohalo<xml::read_string_contents>());
+      co_await xml::ignore_contents(e, /* until */ qname("trkseg"));
+      while (auto mseg = co_await allow_element(e, qname("trkseg"), xml::hohalo<parse_trkseg>()))
+        t.segments.push_back(std::move(*mseg));
+      co_return std::move(t);
+    }
+
+    auto parse_gpx(xml::executor_ref e, xml::attribute_view attrs) -> xml::parser<file> {
+      auto f = file{};
+      if (attrs.lookup(qname("version")) != "1.1"sv)
+        throw std::runtime_error{"expected GPX version to be 1.1"};
+      if (auto mcreator = attrs.lookup(qname("creator")))
+        f.creator = *mcreator;
+      else
+        throw std::runtime_error{"expected GPX file to have creator"};
+
+      if (auto mmeta = co_await allow_element(e, qname("metadata"), xml::hohalo<parse_metadata>()))
+        f.meta = *mmeta;
+      co_await xml::ignore_contents(e, /* until */ qname("trk"));
+      while (auto mtrk = co_await allow_element(e, qname("trk"), xml::hohalo<parse_trk>()))
+        f.tracks.push_back(std::move(*mtrk));
+      co_await allow_element(e, qname("extensions"), xml::hohalo<xml::ignore_element_contents>());
+
+      co_return std::move(f);
+    }
+
+  } // namespace v11
+
+  auto parse_file(xml::executor_ref e) -> xml::parser<file> {
+    auto decl = co_await expect_event<xml::xml_decl_event>(e);
+    if (decl.version != "1.0"sv)
+      throw std::runtime_error{std::format("unsupported XML version, got {}", std::string_view{decl.version})};
+    if (decl.encoding != "UTF-8"sv)
+      throw std::runtime_error{"unsupported encoding"};
+    if (auto mf = co_await allow_element(e, v10::qname("gpx"), xml::hohalo<v10::parse_gpx>()))
+      co_return std::move(*mf);
+    if (auto mf = co_await allow_element(e, v11::qname("gpx"), xml::hohalo<v11::parse_gpx>()))
+      co_return std::move(*mf);
+    throw std::runtime_error{"no supported GPX document found"};
+  }
+
+  reader::reader()
+    : p_{parse_file(util::not_null{&e_})}
+  { e_.set_continuation(p_.promise().base_handle()); }
+
+  auto reader::init() -> void {
+    e_.start();
+  }
+
+  auto reader::put(std::string_view buf) -> void {
+    e_.read(buf, false);
+  }
+
+  auto reader::finish() -> gpx::file {
+    e_.read(std::string_view{}, true);
+    e_.end();
+    // Promise is still alive since the last coroutine performs a
+    // symmetric transfer to std::noop_coroutine() in final_suspend().
+    return std::move(p_.promise().returned_value());
+  }
+
+} // namespace routemon::gpx