Change in logic while aplying gps fixes to dives

We were actually searching dives which match the dowloaded position
fixes. So we're also trying to take into account if the fix is automatic
or no based on a limited amount of predefined strings (bad idea, as the
user can change in companion app settings the predefined string).
This way, in actual implementation, if program concludes that a fix has
been manually got or, simply, the user is unlucky enough to have all the
position fixes out of the dive time, find_dive_n_near() function will
pair fix and dive in an ordered way (1st fix -> 1st dive; 2nd fix -> 2nd
dive ...) which is probably erroneous, except for manual position fixes.

BTW actual implementation can't pair the same gps position with more
than one dive, which would be the case, e.g. in repetitive dives while at
anchor in the same point.

The patch changes the logic:

- Search positions for defined dives (instead of dives for defined
positions) without care if position has manually or  automatically been
set.
- Only take care of those dives that don't have a position yet.
- It makes two assumptions:
   a.- If the position fix has been taken during the dive time, is
correct. If there are more than one inside the dive time, takes the
first one (closest to the DC's reported time).
   b.- If not during diving time, the correct one is the nearest fix
before the dive begins (also the usual case if manually fixed from the
smartphone just before jump into the water). But will work too if there
is only one fix *in SAME_GROUP range* after the dive (another usual
case).
- Finally, as copy_gps_location() in dive.h is used only here, let it
take care of naming the dive if user hasn't named it yet.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

2 files changed, 53 insertions, 50 deletions

diff --git a/dive.h b/dive.h
index 4978f4f9a..e2442818c 100644
--- a/dive.h
+++ b/dive.h
@@ -326,6 +326,9 @@ static inline void copy_gps_location(struct dive *from, struct dive *to)
 	if (from && to) {
 		to->latitude.udeg = from->latitude.udeg;
 		to->longitude.udeg = from->longitude.udeg;
+		if (!to->location) {
+			to->location = strdup(from->location);
+		}
 	}
 }
 
diff --git a/qt-ui/subsurfacewebservices.cpp b/qt-ui/subsurfacewebservices.cpp
index 0514d89a9..23972587e 100644
--- a/qt-ui/subsurfacewebservices.cpp
+++ b/qt-ui/subsurfacewebservices.cpp
@@ -31,69 +31,69 @@
 struct dive_table gps_location_table;
 static bool merge_locations_into_dives(void);
 
-static bool is_automatic_fix(struct dive *gpsfix)
-{
-	if (gpsfix && gpsfix->location &&
-	    (!strcmp(gpsfix->location, "automatic fix") ||
-	     !strcmp(gpsfix->location, "Auto-created dive")))
-		return true;
-	return false;
-}
-
 #define SAME_GROUP 6 * 3600 // six hours
 //TODO: C Code. static functions are not good if we plan to have a test for them.
 static bool merge_locations_into_dives(void)
 {
-	int i, nr = 0, changed = 0;
-	struct dive *gpsfix, *last_named_fix = NULL, *dive;
+	int i, j, tracer=0, changed=0;
+	struct dive *gpsfix, *nextgpsfix, *dive;
 
 	sort_table(&gps_location_table);
 
-	for_each_gps_location (i, gpsfix) {
-		if (is_automatic_fix(gpsfix) && (dive = find_dive_including(gpsfix->when))) {
-			if (dive && !dive_has_gps_location(dive)) {
-#if DEBUG_WEBSERVICE
-				struct tm tm;
-				utc_mkdate(gpsfix->when, &tm);
-				printf("found dive named %s @ %04d-%02d-%02d %02d:%02d:%02d\n",
-				       gpsfix->location,
-				       tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-				       tm.tm_hour, tm.tm_min, tm.tm_sec);
-#endif
-				changed++;
-				copy_gps_location(gpsfix, dive);
-			}
-		} else {
-			if (last_named_fix && dive_within_time_range(last_named_fix, gpsfix->when, SAME_GROUP)) {
-				nr++;
-			} else {
-				nr = 1;
-				last_named_fix = gpsfix;
-			}
-			dive = find_dive_n_near(gpsfix->when, nr, SAME_GROUP);
-			if (dive) {
-				if (!dive_has_gps_location(dive)) {
-					copy_gps_location(gpsfix, dive);
-					changed++;
-				}
-				if (!dive->location) {
-					dive->location = strdup(gpsfix->location);
-					changed++;
+	for_each_dive (i, dive) {
+		if (!dive_has_gps_location(dive)) {
+			for (j = tracer; (gpsfix = get_gps_location(j, &gps_location_table)) !=NULL; j++) {
+				if (dive_within_time_range (dive, gpsfix->when, SAME_GROUP)) {
+					/*
+					 * If position is fixed during dive. This is the good one.
+					 * Asign and mark position, and end gps_location loop
+					 */
+					if ((dive->when <= gpsfix->when && gpsfix->when <= dive->when + dive->duration.seconds)) {
+						copy_gps_location(gpsfix,dive);
+						changed++;
+						tracer = j;
+						break;
+					} else {
+						/*
+						 * If it is not, check if there are more position fixes in SAME_GROUP range
+						 */
+						if ((nextgpsfix = get_gps_location(j+1,&gps_location_table)) &&
+						    dive_within_time_range (dive, nextgpsfix->when, SAME_GROUP)) {
+							/*
+							 * If distance from gpsfix to end of dive is shorter than distance between
+							 * gpsfix and nextgpsfix, gpsfix is the good one. Asign, mark and end loop.
+							 * If not, simply fail and nextgpsfix will be evaluated in next iteration.
+							 */
+							if ((dive->when + dive->duration.seconds - gpsfix->when) < (nextgpsfix->when - gpsfix->when)) {
+								copy_gps_location(gpsfix,dive);
+								tracer = j;
+								break;
+							}
+						/*
+						 * If no more positions in range, the actual is the one. Asign, mark and end loop.
+						 */
+						} else {
+							copy_gps_location(gpsfix,dive);
+							changed++;
+							tracer = j;
+							break;
+						}
+					}
+				} else {
+					/* If position is out of SAME_GROUP range and in the future, mark position for
+					 * next dive iteration and end the gps_location loop
+					 */
+					if (gpsfix->when >= dive->when + dive->duration.seconds + SAME_GROUP) {
+						tracer = j;
+						break;
+					}
 				}
-			} else {
-				struct tm tm;
-				utc_mkdate(gpsfix->when, &tm);
-#if DEBUG_WEBSERVICE
-				printf("didn't find dive matching gps fix named %s @ %04d-%02d-%02d %02d:%02d:%02d\n",
-				       gpsfix->location,
-				       tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
-				       tm.tm_hour, tm.tm_min, tm.tm_sec);
-#endif
 			}
 		}
 	}
 	return changed > 0;
 }
+
 //TODO: C-code.
 static void clear_table(struct dive_table *table)
 {