[gnome-maps/wip/mlundblad/transit-plugin-opendatach: 5/5] WIP: Add transit plugin for opendata.ch

[Marcus Lundblad <mlundblad src gnome org>]

commit 032ae5b7a91dbe18d5e5c12b87fdb883a91426b0
Author: Marcus Lundblad <ml update uu se>
Date:   Sun Nov 3 22:36:56 2019 +0100

    WIP: Add transit plugin for opendata.ch

 src/org.gnome.Maps.src.gresource.xml |   1 +
 src/transitplugins/opendataCH.js     | 345 +++++++++++++++++++++++++++++++++++
 2 files changed, 346 insertions(+)
---
diff --git a/src/org.gnome.Maps.src.gresource.xml b/src/org.gnome.Maps.src.gresource.xml
index 19475973..961ac33f 100644
--- a/src/org.gnome.Maps.src.gresource.xml
+++ b/src/org.gnome.Maps.src.gresource.xml
@@ -113,6 +113,7 @@
     <file alias="geojsonvt/tile.js">tile.js</file>
     <file alias="geojsonvt/transform.js">transform.js</file>
     <file alias="geojsonvt/wrap.js">wrap.js</file>
+    <file>transitplugins/opendataCH.js</file>
     <file>transitplugins/openTripPlanner.js</file>
     <file>transitplugins/resrobot.js</file>
   </gresource>
diff --git a/src/transitplugins/opendataCH.js b/src/transitplugins/opendataCH.js
new file mode 100644
index 00000000..8a8bbb42
--- /dev/null
+++ b/src/transitplugins/opendataCH.js
@@ -0,0 +1,345 @@
+/* -*- Mode: JS2; indent-tabs-mode: nil; js2-basic-offset: 4 -*- */
+/* vim: set et ts=4 sw=4: */
+/*
+ * Copyright (c) 2019 Marcus Lundblad
+ *
+ * GNOME Maps is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * GNOME Maps is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with GNOME Maps; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Marcus Lundblad <ml update uu se>
+ */
+
+/**
+ * This module implements a transit routing plugin for the Swiss national
+ * opendata.ch transit journey planning API.
+ *
+ * API docs for opendata.ch journey planning can be found at:
+ * https://transport.opendata.ch/docs.html
+ */
+
+const Champlain = imports.gi.Champlain;
+const GLib = imports.gi.GLib;
+const Soup = imports.gi.Soup;
+
+const Application = imports.application;
+const HTTP = imports.http;
+const TransitPlan = imports.transitPlan;
+const Utils = imports.utils;
+
+const BASE_URL = 'https://transport.opendata.ch';
+const API_VERSION = 'v1';
+
+const Transportations = {
+    TRAIN:    'train',
+    TRAM:     'tram',
+    SHIP:     'ship',
+    BUS:      'bus',
+    CABLEWAY: 'cableway'
+};
+
+var OpendataCH = class OpendataCH {
+    constructor() {
+        this._session = new Soup.Session({ user_agent : 'gnome-maps/' + pkg.version });
+        this._plan = Application.routingDelegator.transitRouter.plan;
+        this._query = Application.routeQuery;
+    }
+
+    fetchFirstResults() {
+        let filledPoints = this._query.filledPoints;
+
+        this._extendPrevious = false;
+
+        if (filledPoints.length > 7) {
+            Utils.debug('This plugin supports at most five via location');
+            this._plan.reset();
+            this._plan.requestFailed();
+            this._query.reset();
+        } else {
+            this._fetchResults();
+        }
+    }
+
+    fetchMoreResults() {
+        this._extendPrevious = true;
+
+        this._fetchResults();
+    }
+
+    _fetchResults() {
+        let query = new HTTP.Query(this._getQueryParams());
+        let uri = new Soup.URI(BASE_URL + '/' + API_VERSION + '/connections?' +
+                               query.toString());
+        let request = new Soup.Message({ method: 'GET', uri: uri });
+
+        Utils.debug('uri: ' + uri.to_string(true));
+
+        this._session.queue_message(request, (obj, message) => {
+            if (message.status_code !== Soup.Status.OK) {
+                Utils.debug('Failed to get trip: ' + message.status_code);
+                this._plan.requestFailed();
+                this._plan.reset();
+            } else {
+                let result = JSON.parse(message.response_body.data);
+                Utils.debug('result: ' + JSON.stringify(result, null, 2));
+
+                if (result.connections && result.connections.length > 0) {
+                    let itineraries = this._createItineraries(result.connections);
+
+                    this._plan.updateWithNewItineraries(itineraries,
+                                                        this._query.arriveBy,
+                                                        this._extendPrevious);
+                } else {
+                    this._plan.noRouteFound();
+                }
+            }
+        });
+    }
+
+    _createItineraries(connections) {
+        return connections.map((connection) => this._createItinerary(connection));
+    }
+
+    _createItinerary(connection) {
+        let legs = this._createLegs(connection.sections);
+        let duration =
+            connection.to.arrivalTimestamp - connection.from.departureTimestamp;
+        let from = connection.from;
+        let to = connection.to;
+        let [startTime,] = this._parseTime(from.departure);
+        let [endTime,] = this._parseTime(to.arrival);
+
+        return new TransitPlan.Itinerary({ duration:  duration,
+                                           departure: startTime,
+                                           arrival:   endTime,
+                                           legs:      legs,
+                                           duration:  duration });
+    }
+
+    /**
+     * Parse a time string into an array with
+     * an absolute timestamp in ms since Unix epoch and a timezone offset
+     * for the provider's native timezone at the given time and date
+     */
+    _parseTime(timeString) {
+        let dateTime = GLib.DateTime.new_from_iso8601(timeString, null);
+
+        return [dateTime.to_unix() * 1000, dateTime.get_utc_offset() / 1000];
+    }
+
+    _createLegs(sections) {
+        let result = sections.map((section, index, sections) =>
+                                    this._createLeg(section, index, sections));
+
+        return result;
+    }
+
+    _createLeg(section, index, sections) {
+        let isTransit = section.journey;
+
+        let departure = section.departure;
+        let arrival = section.arrival;
+        let journey = section.journey;
+
+        if (!departure)
+            throw new Error('Missing departure element');
+        if (!arrival)
+            throw new Error('Missing arrival element');
+
+        let first = index === 0;
+        let last = index === sections.length - 1;
+        /* for walking legs in the beginning or end, use the name from the
+         * query, so we get the names of the place the user searched for in
+         * the results, when starting/ending at a transitstop, use the stop
+         * name
+         */
+        let from =
+            first && !journey ? this._query.filledPoints[0].place.name :
+                                departure.station.name;
+        let to =
+            last && !journey ? this._query.filledPoints.last().place.name :
+                               arrival.station.nam;
+        let [departureTime, tzOffset] = this._parseTime(departure.departure);
+        let [arrivalTime,] = this._parseTime(arrival.arrival);
+        let route = journey ? journey.number : null;
+        let routeType =
+            journey ? this._getHVTCodeFromCategory(journey.category) : null;
+        let agencyName = journey ? journey.operator : null;
+        let polyline = this._createPolylineForSection(section, index, sections);
+        let duration = arrival.arrivalTimestamp - departure.departureTimestamp;
+        let headsign = journey ? journey.to : null;
+        let [departureX, departureY, arrivalX, arrivalY] =
+            this._getCoordsForSection(section, index, sections);
+
+        let result = new TransitPlan.Leg({ departure:            departureTime,
+                                           arrival:              arrivalTime,
+                                           from:                 from,
+                                           to:                   to,
+                                           headsign:             headsign,
+                                           fromCoordinate:       [departureX,
+                                                                  departureY],
+                                           toCoordinate:         [arrivalX,
+                                                                  arrivalY],
+                                           route:                route,
+                                           routeType:            routeType,
+                                           polyline:             polyline,
+                                           isTransit:            isTransit,
+                                           duration:             duration,
+                                           agencyName:           agencyName,
+                                           agencyTimezoneOffset: tzOffset,
+                                           tripShortName:        route });
+
+        if (journey)
+            result.intermediateStops = this._createIntermediateStops(journey);
+
+        return result;
+    }
+
+    _getHVTCodeFromCategory(category) {
+        // TODO: parse category
+        return null;
+    }
+
+    _getCoordsForSection(section, index, sections) {
+        let departureX = section.departure.location.coordinate.x;
+        let departureY = section.departure.location.coordinate.y;
+        let arrivalX = section.arrival.location.coordinate.x;
+        let arrivalY = section.arrival.location.coordinate.y;
+
+        if (index === 0) {
+            if (!departureX)
+                departureX = this._query.filledPoints[0].place.location.latitude;
+            if (!departureY)
+                departureY = this._query.filledPoints[0].place.location.longitude;
+        } else if (index === sections.length - 1)  {
+            if (!arrivalX)
+                arrivalX = this._query.filledPoints.last().place.location.latitude;
+            if (!arrivalY)
+                arrivalY = this._query.filledPoints.last().place.location.longitude;
+        }
+
+        return [departureX, departureY, arrivalX, arrivalY];
+    }
+
+    _createPolylineForSection(section, index, sections) {
+        let polyline;
+
+        if (section.journey) {
+            polyline = [];
+
+            section.journey.passList.forEach((pass) => {
+                let coordinate = pass.location.coordinate;
+                polyline.push(new Champlain.Coordinate({ latitude:  coordinate.x,
+                                                         longitude: coordinate.y }));
+            });
+        } else {
+            let [departureX, departureY, arrivalX, arrivalY] =
+                this._getCoordsForSection(section, index, sections);
+
+            polyline =
+                [new Champlain.Coordinate({ latitude:  departureX,
+                                            longitude: departureY }),
+                 new Champlain.Coordinate({ latitude:  arrivalX,
+                                            longitude: arrivalY })];
+        }
+
+        return polyline;
+    }
+
+    _createIntermediateStops(journey) {
+        let result = [];
+
+        journey.passList.forEach((pass, index) => {
+            if (index !== 0)
+                result.push(this._createIntermediateStop(pass));
+        });
+
+        return result;
+    }
+
+    _createIntermediateStop(pass) {
+        let [departure, departureTzOffset] = [,];
+        let [arrival, arrivalTzOffset] = [,];
+
+        if (pass.departure)
+            [departure, departureTzOffset] = this._parseTime(pass.departure)
+        if (pass.arrival)
+            [arrival, arrivalTzOffset] = this._parseTime(pass.arrival);
+
+        if (!arrival)
+            arrival = departure;
+        if (!departure)
+            departure = arrival;
+
+        return new TransitPlan.Stop({ name:                 pass.station.name,
+                                      arrival:              arrival,
+                                      departure:            departure,
+                                      agencyTimezoneOffset: departureTzOffset || arrivalTzOffset,
+                                      coordinate: [pass.location.coordinate.x,
+                                                   pass.location.coordinate.y] });
+    }
+
+    _getQueryParams() {
+        let points = this._query.filledPoints;
+        let originLocation = points[0].place.location;
+        let destLocation = points.last().place.location;
+        let transitOptions = this._query.transitOptions;
+        let params = { from:  originLocation.latitude + ',' + originLocation.longitude,
+                       to:    destLocation.latitude + ',' + destLocation.longitude };
+
+        if (!transitOptions.showAllTransitTypes)
+            params.transportations = this._getTransportations(transitOptions);
+
+        if (this._extendPrevious) {
+            // TODO: pagination
+        } else  {
+            if (this._query.arriveBy)
+                params.isArrivalTime = 1;
+
+            if (this._query.time)
+                params.time = this._query.time;
+
+            if (this._query.date)
+                params.date = this._query.date;
+        }
+
+        return params;
+    }
+
+    _getTransportations(transitOptions) {
+        let transportations = [];
+
+        this._query.transitOptions.transitTypes.forEach((type) => {
+            let transportation = this._transportationForTransitType(type);
+
+            if (transportation)
+                transportations.push(transportation);
+        });
+
+        return transportations;
+    }
+
+    _transportationForTransitType(type) {
+        switch (type) {
+            case TransitPlan.RouteType.BUS:
+                return Transportations.BUS;
+            case TransitPlan.RouteType.TRAM:
+                return Transportations.TRAM;
+            case TransitPlan.RouteType.TRAIN:
+                return Transportations.TRAIN;
+            case TransitPlan.RouteType.FERRY:
+                return Transportations.SHIP;
+            default:
+                return null;
+        }
+    }
+}