de-duplicate gpx_xml

3 files changed, 117 insertions, 92 deletions

diff --git a/fietsboek/geo.py b/fietsboek/geo.py
index c0a10e7..e6abb71 100644
--- a/fietsboek/geo.py
+++ b/fietsboek/geo.py
@@ -1,9 +1,13 @@
 """This module implements GPS related functionality."""
 
+import datetime
+import io
 from dataclasses import dataclass
 from itertools import islice
 from math import cos, radians, sin, sqrt
 
+from . import util
+
 # WGS-84 equatorial radius, also called the semi-major axis.
 # https://en.wikipedia.org/wiki/Earth_radius
 EARTH_RADIUS = 6378137.0
@@ -15,6 +19,17 @@ MOVING_THRESHOLD = 1.1
 
 
 @dataclass
+class Waypoint:
+    """A waypoint, a special landmark marked in the track."""
+
+    longitude: float
+    latitude: float
+    elevation: float | None
+    name: str | None
+    description: str | None
+
+
+@dataclass
 class MovementData:
     """Movement statistics for a path."""
 
@@ -146,3 +161,76 @@ class Path:
         else:
             movement_data.average_speed = 0.0
         return movement_data
+
+
+def gpx_xml(
+    title: str | None,
+    description: str | None,
+    date: datetime.datetime,
+    points: list[Point],
+    waypoints: list[Waypoint],
+) -> bytes:
+    """Returns an XML representation of the given path.
+
+    :param title: The title of the resulting track.
+    :param description: The description of the resulting track.
+    :param points: The points that make up this track.
+    :param waypoints: The waypoints that should be included.
+    :return: The XML representation (a GPX file).
+    """
+    # This is a cumbersome way to do it, as we're re-implementing XML
+    # serialization logic. However, recreating the track in gpxpy and
+    # letting it serialize it is much slower:
+    # For a track with around 50,000 points, the gpxpy method takes
+    # ~5.9 seconds here, while the "manual" buffer takes only ~2.4 seconds.
+    # This is a speed-up we're happy to take!
+    buf = io.BytesIO()
+    buf.write(b'<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>')
+    buf.write(b'<gpx version="1.1" xmlns="http://www.topografix.com/GPX/1/1">')
+
+    buf.write(b"<metadata>")
+    if title:
+        buf.write(b"<name>%s</name>" % util.xml_escape(title))
+    if description:
+        buf.write(b"<desc>%s</desc>" % util.xml_escape(description))
+    buf.write(b"</metadata>")
+
+    # Cache for fast access
+    write = buf.write
+
+    write(b"<trk>")
+    write(b"<trkseg>")
+    for point in points:
+        write(b'<trkpt lat="')
+        write(str(point.latitude).encode("ascii"))
+        write(b'" lon="')
+        write(str(point.longitude).encode("ascii"))
+        write(b'">')
+        write(b"<ele>")
+        write(str(point.elevation).encode("ascii"))
+        write(b"</ele>")
+        write(b"<time>")
+        write(str(date + datetime.timedelta(seconds=point.time_offset)).encode("ascii"))
+        write(b"</time>")
+        write(b"</trkpt>\n")
+    write(b"</trkseg>")
+    write(b"</trk>")
+
+    # This loop is not as hot:
+    for wpt in waypoints:
+        write(
+            b'<wpt lat="%s" lon="%s">'
+            % (util.xml_escape(str(wpt.latitude)), util.xml_escape(str(wpt.longitude)))
+        )
+        if wpt.elevation is not None:
+            write(b"<ele>%s</ele>" % util.xml_escape(str(wpt.elevation)))
+        if wpt.name is not None:
+            write(b"<name>%s</name>" % util.xml_escape(wpt.name))
+        if wpt.description is not None:
+            write(b"<cmt>%s</cmt>" % util.xml_escape(wpt.description))
+            write(b"<desc>%s</desc>" % util.xml_escape(wpt.description))
+        write(b"</wpt>")
+
+    write(b"</gpx>")
+
+    return buf.getvalue()
diff --git a/fietsboek/models/journey.py b/fietsboek/models/journey.py
index d90db55..81bf30c 100644
--- a/fietsboek/models/journey.py
+++ b/fietsboek/models/journey.py
@@ -1,3 +1,4 @@
+import datetime
 import dataclasses
 import io
 import logging
@@ -159,39 +160,14 @@ class Journey(Base):
         return geo.Path(points)
 
     def gpx_xml(self) -> bytes:
-        buf = io.BytesIO()
-        buf.write(b'<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>')
-        buf.write(b'<gpx version="1.1" xmlns="http://www.topografix.com/GPX/1/1">')
-
-        buf.write(b"<metadata>")
-        if self.title:
-            buf.write(b"<name>%s</name>" % util.xml_escape(self.title))
-        if self.description:
-            buf.write(b"<desc>%s</desc>" % util.xml_escape(self.description))
-        buf.write(b"</metadata>")
-
-        # Cache for easy access, especially the date is important since it's a
-        # dynamic property
-        write = buf.write
-
-        write(b"<trk>")
-        write(b"<trkseg>")
-        for point in self.path().points:
-            write(b'<trkpt lat="')
-            write(str(point.latitude).encode("ascii"))
-            write(b'" lon="')
-            write(str(point.longitude).encode("ascii"))
-            write(b'">')
-            write(b"<ele>")
-            write(str(point.elevation).encode("ascii"))
-            write(b"</ele>")
-            write(b"</trkpt>\n")
-        write(b"</trkseg>")
-        write(b"</trk>")
-
-        write(b"</gpx>")
-
-        return buf.getvalue()
+        return geo.gpx_xml(
+            self.title,
+            self.description,
+            datetime.datetime.fromtimestamp(0).replace(tzinfo=datetime.UTC),
+            self.path().points,
+            []
+        )
+
 
 __all__ = [
 ]
diff --git a/fietsboek/models/track.py b/fietsboek/models/track.py
index fc5a68b..2fec844 100644
--- a/fietsboek/models/track.py
+++ b/fietsboek/models/track.py
@@ -17,7 +17,6 @@ meta information.
 import datetime
 import enum
 import gzip
-import io
 import json
 import logging
 from itertools import chain
@@ -176,6 +175,19 @@ class Waypoint(Base):
 
     track: Mapped["Track"] = relationship("Track", back_populates="waypoints")
 
+    def to_geo_waypoint(self) -> geo.Waypoint:
+        """Converts this waypoint (a database object) to a plain waypoint.
+
+        :return: The converted point.
+        """
+        return geo.Waypoint(
+            latitude=self.latitude,
+            longitude=self.longitude,
+            elevation=self.elevation,
+            name=self.name,
+            description=self.description,
+        )
+
 
 class TrackPoint(Base):
     """A track point represents a single GPS point along a path."""
@@ -438,64 +450,13 @@ class Track(Base):
 
         :return: The XML representation (a GPX file).
         """
-        # This is a cumbersome way to do it, as we're re-implementing XML
-        # serialization logic. However, recreating the track in gpxpy and
-        # letting it serialize it is much slower:
-        # For a track with around 50,000 points, the gpxpy method takes
-        # ~5.9 seconds here, while the "manual" buffer takes only ~2.4 seconds.
-        # This is a speed-up we're happy to take!
-        buf = io.BytesIO()
-        buf.write(b'<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>')
-        buf.write(b'<gpx version="1.1" xmlns="http://www.topografix.com/GPX/1/1">')
-
-        buf.write(b"<metadata>")
-        if self.title:
-            buf.write(b"<name>%s</name>" % util.xml_escape(self.title))
-        if self.description:
-            buf.write(b"<desc>%s</desc>" % util.xml_escape(self.description))
-        buf.write(b"</metadata>")
-
-        # Cache for easy access, especially the date is important since it's a
-        # dynamic property
-        date = self.date
-        write = buf.write
-
-        write(b"<trk>")
-        write(b"<trkseg>")
-        for point in self.path().points:
-            write(b'<trkpt lat="')
-            write(str(point.latitude).encode("ascii"))
-            write(b'" lon="')
-            write(str(point.longitude).encode("ascii"))
-            write(b'">')
-            write(b"<ele>")
-            write(str(point.elevation).encode("ascii"))
-            write(b"</ele>")
-            write(b"<time>")
-            write(str(date + datetime.timedelta(seconds=point.time_offset)).encode("ascii"))
-            write(b"</time>")
-            write(b"</trkpt>\n")
-        write(b"</trkseg>")
-        write(b"</trk>")
-
-        # This loop is not as hot:
-        for wpt in self.waypoints:
-            write(
-                b'<wpt lat="%s" lon="%s">'
-                % (util.xml_escape(str(wpt.latitude)), util.xml_escape(str(wpt.longitude)))
-            )
-            if wpt.elevation is not None:
-                write(b"<ele>%s</ele>" % util.xml_escape(str(wpt.elevation)))
-            if wpt.name is not None:
-                write(b"<name>%s</name>" % util.xml_escape(wpt.name))
-            if wpt.description is not None:
-                write(b"<cmt>%s</cmt>" % util.xml_escape(wpt.description))
-                write(b"<desc>%s</desc>" % util.xml_escape(wpt.description))
-            write(b"</wpt>")
-
-        write(b"</gpx>")
-
-        return buf.getvalue()
+        return geo.gpx_xml(
+            self.title,
+            self.description,
+            self.date,
+            self.path().points,
+            [wpt.to_geo_waypoint() for wpt in self.waypoints],
+        )
 
     @property
     def date(self):