From 8ef67e0cee05a993d060e3cc035c3845464f5dd9 Mon Sep 17 00:00:00 2001
From: Edward Betts <edward@4angle.com>
Date: Fri, 5 Apr 2024 15:58:44 +0200
Subject: [PATCH] Add train route distance info

---
 agenda/travel.py         | 48 +++++++++++++++++++++++++++++++++++++++-
 templates/macros.html    |  7 ++++++
 templates/travel.html    |  4 ++--
 templates/trip_list.html |  2 +-
 templates/trip_page.html |  2 +-
 web_view.py              | 14 ++++++++++--
 6 files changed, 70 insertions(+), 7 deletions(-)

diff --git a/agenda/travel.py b/agenda/travel.py
index d3f5975..6e3d2c9 100644
--- a/agenda/travel.py
+++ b/agenda/travel.py
@@ -1,12 +1,14 @@
 """Travel."""
 
+import json
 import os
 import typing
 
 import flask
 import yaml
+from geopy.distance import geodesic
 
-from .types import Event
+from .types import Event, StrDict
 
 Leg = dict[str, str]
 
@@ -63,3 +65,47 @@ def flight_number(flight: Leg) -> str:
 def all_events(data_dir: str) -> list[Event]:
     """Get all flights and rail journeys."""
     return get_trains(data_dir) + get_flights(data_dir)
+
+
+RouteDistances = dict[tuple[str, str], float]
+
+
+def train_leg_distance(geojson_data: StrDict) -> float:
+    """Calculate the total length of a LineString in kilometers from GeoJSON data."""
+    # Extract coordinates
+    first_object = geojson_data["features"][0]["geometry"]
+    assert first_object["type"] in ("LineString", "MultiLineString")
+
+    if first_object["type"] == "LineString":
+        coord_list = [first_object["coordinates"]]
+    else:
+        first_object["type"] == "MultiLineString"
+        coord_list = first_object["coordinates"]
+    # pprint(coordinates)
+
+    total_length_km = 0.0
+
+    for coordinates in coord_list:
+        total_length_km += sum(
+            float(geodesic(coordinates[i], coordinates[i + 1]).km)
+            for i in range(len(coordinates) - 1)
+        )
+
+    return total_length_km
+
+
+def load_route_distances(data_dir: str) -> RouteDistances:
+    """Load cache of route distances."""
+    route_distances: RouteDistances = {}
+    with open(os.path.join(data_dir, "route_distances.json")) as f:
+        for s1, s2, dist in json.load(f):
+            route_distances[(s1, s2)] = dist
+
+    return route_distances
+
+
+def add_leg_route_distance(leg: StrDict, route_distances: RouteDistances) -> None:
+    s1, s2 = sorted([leg["from"], leg["to"]])
+    dist = route_distances.get((s1, s2))
+    if dist:
+        leg["distance"] = dist
diff --git a/templates/macros.html b/templates/macros.html
index d1d42a8..c52531b 100644
--- a/templates/macros.html
+++ b/templates/macros.html
@@ -98,6 +98,8 @@
     | <a href="https://uk.flightaware.com/live/flight/{{ full_flight_number | replace("U2", "EZY") }}">FlightAware</a>
     | <a href="{{ radarbox_url }}">radarbox</a>
   </div>
+  <div class="grid-item">
+  </div>
 {% endmacro %}
 
 {% macro train_row(item) %}
@@ -131,4 +133,9 @@
       {% endif %}
     {% endfor %}
   </div>
+  <div class="grid-item text-end">
+    {% if item.distance %}
+      {{ "{:.1f} km / {:.1f} miles".format(item.distance, item.distance / 1.60934) }}
+    {% endif %}
+  </div>
 {% endmacro %}
diff --git a/templates/travel.html b/templates/travel.html
index e0d8161..87dd16b 100644
--- a/templates/travel.html
+++ b/templates/travel.html
@@ -5,14 +5,14 @@
 <style>
 .grid-container {
   display: grid;
-  grid-template-columns: repeat(8, auto);
+  grid-template-columns: repeat(9, auto);
   gap: 10px;
   justify-content: start;
 }
 
 .train-grid-container {
   display: grid;
-  grid-template-columns: repeat(8, auto);
+  grid-template-columns: repeat(9, auto);
   gap: 10px;
   justify-content: start;
 }
diff --git a/templates/trip_list.html b/templates/trip_list.html
index 83525ee..58bc5a9 100644
--- a/templates/trip_list.html
+++ b/templates/trip_list.html
@@ -10,7 +10,7 @@
 
 {% set conference_column_count = 7 %}
 {% set accommodation_column_count = 7 %}
-{% set travel_column_count = 8 %}
+{% set travel_column_count = 9 %}
 <style>
 .conferences {
   display: grid;
diff --git a/templates/trip_page.html b/templates/trip_page.html
index d76ac5a..06437a5 100644
--- a/templates/trip_page.html
+++ b/templates/trip_page.html
@@ -25,7 +25,7 @@
 
 {% set conference_column_count = 7 %}
 {% set accommodation_column_count = 7 %}
-{% set travel_column_count = 8 %}
+{% set travel_column_count = 9 %}
 <style>
 .conferences {
   display: grid;
diff --git a/web_view.py b/web_view.py
index 33be6f7..651518a 100755
--- a/web_view.py
+++ b/web_view.py
@@ -117,6 +117,15 @@ def travel_list() -> str:
         if isinstance(item["depart"], datetime)
     ]
 
+    route_distances = agenda.travel.load_route_distances(app.config["DATA_DIR"])
+
+    for train in trains:
+        for leg in train["legs"]:
+            agenda.travel.add_leg_route_distance(leg, route_distances)
+
+        if all("distance" in leg for leg in train["legs"]):
+            train["distance"] = sum(leg["distance"] for leg in train["legs"])
+
     return flask.render_template("travel.html", flights=flights, trains=trains)
 
 
@@ -300,7 +309,6 @@ def human_readable_delta(future_date: date) -> str | None:
 @app.route("/trip/<start>")
 def trip_page(start: str) -> str:
     """Individual trip page."""
-
     trip_list = [
         trip
         for trip in agenda.trip.build_trip_list()
@@ -341,7 +349,9 @@ def trip_page(start: str) -> str:
 
     for route in routes:
         if "geojson_filename" in route:
-            route["geojson"] = agenda.trip.read_geojson(route.pop("geojson_filename"))
+            route["geojson"] = agenda.trip.read_geojson(
+                app.config["PERSONAL_DATA"], route.pop("geojson_filename")
+            )
 
     if trip.end:
         countries = {c.alpha_2 for c in trip.countries}