[gnome-maps/wip/mlundblad/photon-geocode: 5/13] Add Photon geocode module

[Marcus Lundblad <mlundblad src gnome org>]

commit 1c36d26ac0a04068f64a410da4d8a8f41887a5ec
Author: Marcus Lundblad <ml update uu se>
Date:   Tue Apr 23 23:12:41 2019 +0200

    Add Photon geocode module
    
    Adds a geocoding implementation using
    the Photon geocoder project

 src/org.gnome.Maps.src.gresource.xml |   1 +
 src/photonGeocode.js                 | 173 +++++++++++++++++++++++++++++++++++
 2 files changed, 174 insertions(+)
---
diff --git a/src/org.gnome.Maps.src.gresource.xml b/src/org.gnome.Maps.src.gresource.xml
index 04164ed..d3c2454 100644
--- a/src/org.gnome.Maps.src.gresource.xml
+++ b/src/org.gnome.Maps.src.gresource.xml
@@ -49,6 +49,7 @@
     <file>osmTypes.js</file>
     <file>osmUtils.js</file>
     <file>overpass.js</file>
+    <file>photonGeocode.js</file>
     <file>photonParser.js</file>
     <file>place.js</file>
     <file>placeBubble.js</file>
diff --git a/src/photonGeocode.js b/src/photonGeocode.js
new file mode 100644
index 0000000..09c2250
--- /dev/null
+++ b/src/photonGeocode.js
@@ -0,0 +1,173 @@
+/* -*- 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>
+ */
+
+const Format = imports.format;
+
+const GLib = imports.gi.GLib;
+const Soup = imports.gi.Soup;
+
+const Application = imports.application;
+const HTTP = imports.http;
+const PhotonParser = imports.photonParser;
+const Service = imports.service;
+const Utils = imports.utils;
+
+var PhotonGeocode = class {
+    constructor() {
+        this._session = new Soup.Session({ user_agent : 'gnome-maps/' + pkg.version });
+        this._readService();
+        this._limit = Application.settings.get('max-search-results');
+    }
+
+    search(string, latitude, longitude, cancellable, callback) {
+        let url = this._buildURL(string, latitude, longitude);
+        let msg = Soup.Message.new('GET', url);
+        Utils.debug('URL: ' + url);
+
+        let handler = cancellable.connect(() => {
+            this._session.cancel_message(msg, Soup.Status.CANCELLED);
+        });
+
+        this._session.queue_message(msg, (session, message) => {
+            cancellable.disconnect(handler);
+
+            if (cancellable.is_cancelled())
+                return;
+
+            try {
+                let result = this._parseMessage(message.response_body.data);
+                if (!result)
+                    callback(null, null);
+                else
+                    callback(result, null);
+            } catch (e) {
+                Utils.debug('Error: ' + e);
+                callback(null, e);
+            }
+        });
+    }
+
+    reverse(latitude, longitude, callback) {
+        let url = this._buildURL(null, latitude, longitude);
+        let msg = Soup.Message.new('GET', url);
+        Utils.debug('URL: ' + url);
+
+        Application.application.mark_busy();
+        this._session.queue_message(msg, (session, message) => {
+            Application.application.unmark_busy();
+            try {
+                let result = this._parseMessage(message.response_body.data);
+                if (!result)
+                    callback(null, null);
+                else
+                    callback(result[0], null);
+            } catch (e) {
+                Utils.debug('Error: ' + e);
+                callback(null, e);
+            }
+        });
+    }
+
+    get attribution() {
+        return Service.getService().photonGeocode.attribution;
+    }
+
+    get attributionUrl() {
+        return Service.getService().photonGeocode.attributionUrl;
+    }
+
+    get name() {
+        return 'Photon';
+    }
+
+    get url() {
+        return 'https://github.com/Komoot/photon';
+    }
+
+    _parseMessage(message) {
+        let json = JSON.parse(message);
+        let result = [];
+        let features = json.features;
+
+        if (!features || features.length === 0) {
+            Utils.debug('No features in response');
+            return null;
+        }
+
+        features.forEach(feature => {
+            let place = this._parseFeature(feature);
+
+            if (place)
+                result.push(place);
+        });
+
+        return result;
+    }
+
+    _parseFeature(feature) {
+        let [lon, lat] = feature.geometry.coordinates;
+
+        return PhotonParser.parsePlace(lat, lon, feature.properties);
+    }
+
+    _buildURL(string, latitude, longitude) {
+        let query = new HTTP.Query({ lat:     latitude,
+                                     lon:     longitude,
+                                     limit:   string ? this._limit : 1
+                                   });
+
+        if (string)
+            query.add('q', string);
+        else
+            query.add('distance_sort', 'true');
+
+        if (this._language)
+            query.add('lang', this._language);
+
+        if (this._additionalParams)
+            this._additionalParams.forEach((p) => query.add(p.key, p.value));
+
+        return Format.vprintf('%s/%s/?%s', [this._baseUrl,
+                                            string ? 'api' : 'reverse',
+                                            query.toString()]);
+    }
+
+    _readService() {
+        let photon = Service.getService().photonGeocode;
+        let locale = GLib.get_language_names()[0];
+        // the last item returned is the "bare" language
+        let language = GLib.get_locale_variants(locale).slice(-1)[0];
+        let supportedLanguages;
+
+        if (photon) {
+            this._baseUrl = photon.baseUrl;
+            supportedLanguages = photon.supportedLanguages;
+
+            if (photon.additionalParams)
+                this._additionalParams = photon.additionalParams;
+        }
+
+        if (supportedLanguages.includes(language))
+            this._language = language;
+        else
+            this._language = null;
+    }
+}