From 704af819968157b8a63f10fe751df629024da0ec Mon Sep 17 00:00:00 2001
From: Jan-Piet Mens <jp@mens.de>
Date: Tue, 23 Oct 2018 14:09:32 +0200
Subject: [PATCH] NEW: add support for revgeod 	closes #263

---
 README.md |  4 +++-
 geo.c     | 51 +++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 8bb0b09..e170a0d 100644
--- a/README.md
+++ b/README.md
@@ -269,10 +269,11 @@ This section lists the most important options of the Recorder with their long na
 
 `--precision` overrides the compiled-in default. (See "Precision" later.)
 
-`--geokey` sets the API key for reverse geo lookups. We support Google (legacy) and OpenCage which we recommend [OpenCage](doc/OPENCAGE.md). You will require an API key for both. For backwards-compatibility the API key for Google is used "as is", whereas you prefix the OpenCage API key with the string `"opencage:"`:
+`--geokey` sets the API key for reverse geo lookups. We support Google (legacy) and OpenCage which we recommend [OpenCage](doc/OPENCAGE.md). We also support [revgeod]. You will require an API key for the first two. For backwards-compatibility the API key for Google is used "as is", whereas you prefix the OpenCage API key with the string `"opencage:"`:
 ```
 --geokey "opencage:xxxxxxxxxxxxxxxxxxxxxx"      # for OpenCage
 --geokey "xxxxxxxxxxxxxxxxxxxxxx"               # for Google
+--geokey "revgeod:localhost:8865"               # for Revgeod (host:port)
 ```
 
 (The rules of the game for using Google as reverse geocoder changed in May 2018; make sure to check Google's Map Project documentation before using this)
@@ -969,3 +970,4 @@ It actually is possible to gateway location publishes arriving via HTTP into MQT
 
 If a payload is received with an element called `_geoprec` it contains an override for the Recorder's configured reverse-geo precision. So, for example, if Recorder is running with precision 7, say, and the received payload contains `"_geoprec" : 2` the 2 will be used for this particular publish. This is not used in the OwnTracks apps, but it can be used with payloads you generate otherwise. If `_geoprec` is negative, new reverse geo lookups will not be performed, but cached entries of `abs(_geoprec)` will be used.
 
+  [revgeod]: https://github.com/jpmens/revgeod
diff --git a/geo.c b/geo.c
index 0b8c73d..140a4e8 100644
--- a/geo.c
+++ b/geo.c
@@ -29,13 +29,16 @@
 
 typedef enum {
 	GOOGLE,
-	OPENCAGE
+	OPENCAGE,
+	REVGEOD
 } geocoder;
 
 #define GOOGLE_URL "https://maps.googleapis.com/maps/api/geocode/json?latlng=%lf,%lf&sensor=false&language=EN&key=%s"
 
 #define OPENCAGE_URL "https://api.opencagedata.com/geocode/v1/json?q=%lf+%lf&key=%s&abbrv=1&no_record=1&limit=1&format=json"
 
+#define REVGEOD_URL "http://%s/rev?lat=%lf&lon=%lf"	/* "host:port", lat, lon */
+
 static CURL *curl;
 
 static size_t writemem(void *contents, size_t size, size_t nmemb, void *userp)
@@ -139,6 +142,43 @@ static int goog_decode(UT_string *geodata, UT_string *addr, UT_string *cc, UT_st
 	return (1);
 }
 
+static int revgeod_decode(UT_string *geodata, UT_string *addr, UT_string *cc, UT_string *locality)
+{
+	JsonNode *json, *village, *j, *a;
+
+	/*
+	* We are parsing this data returned from revgeod(1):
+	*
+	* {"address":{"village":"La Terre Noire, 77510 Sablonnières, France","locality":"Sablonnières","cc":"FR","s":"lmdb"}}
+	*
+	*/
+
+	if ((json = json_decode(UB(geodata))) == NULL) {
+		return (0);
+	}
+
+	if ((a = json_find_member(json, "address")) != NULL) {
+		if ((village = json_find_member(a, "village")) != NULL) {
+			if (village->tag == JSON_STRING) {
+				utstring_printf(addr, "%s", village->string_);
+			}
+		}
+		if ((j = json_find_member(a, "locality")) != NULL) {
+			if (j->tag == JSON_STRING) {
+				utstring_printf(locality, "%s", j->string_);
+			}
+		}
+		if ((j = json_find_member(a, "cc")) != NULL) {
+			if (j->tag == JSON_STRING) {
+				utstring_printf(cc, "%s", j->string_);
+			}
+		}
+	}
+
+	json_delete(json);
+	return (1);
+}
+
 static int opencage_decode(UT_string *geodata, UT_string *addr, UT_string *cc, UT_string *locality)
 {
 	JsonNode *json, *results, *address, *ac, *zeroth;
@@ -267,12 +307,16 @@ JsonNode *revgeo(struct udata *ud, double lat, double lon, UT_string *addr, UT_s
 	if (strncmp(ud->geokey, "opencage:", strlen("opencage:")) == 0) {
 		utstring_printf(url, OPENCAGE_URL, lat, lon, ud->geokey + strlen("opencage:"));
 		geocoder = OPENCAGE;
+	} else if (strncmp(ud->geokey, "revgeod:", strlen("revgeod:")) == 0) {
+		/* revgeod:localhost:8865 */
+		utstring_printf(url, REVGEOD_URL, ud->geokey + strlen("revgeod:"), lat, lon);
+		geocoder = REVGEOD;
 	} else {
 		utstring_printf(url, GOOGLE_URL, lat, lon, ud->geokey);
 		geocoder = GOOGLE;
 	}
 
-	// printf("--------------- %s\n", UB(url));
+	// fprintf(stderr, "--------------- %s\n", UB(url));
 
 	curl_easy_setopt(curl, CURLOPT_URL, UB(url));
 	curl_easy_setopt(curl, CURLOPT_USERAGENT, "OwnTracks-Recorder/1.0");
@@ -302,6 +346,9 @@ JsonNode *revgeo(struct udata *ud, double lat, double lon, UT_string *addr, UT_s
 		case OPENCAGE:
 			rc = opencage_decode(cbuf, addr, cc, locality);
 			break;
+		case REVGEOD:
+			rc = revgeod_decode(cbuf, addr, cc, locality);
+			break;
 	}
 
 	if (!rc) {