Start merging dives by keeping the dive computer data from both dives

Also, note that we do *not* do the "find_sample_offset()" any more when
we merge two dives that happen at the same time - since we just keep
both sets of dive computer data around.

But we keep the function to find the best offset around, because we may
well want to use it later when *showing* the dive, and trying to match
up the different sample data from the multiple dive computers associated
with the dive.

Because of that, this causes warnings about the now unused function.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 120 insertions, 11 deletions

diff --git a/dive.c b/dive.c
index d69aee355..43cafacbf 100644
--- a/dive.c
+++ b/dive.c
@@ -1051,21 +1051,100 @@ static int find_sample_offset(struct divecomputer *a, struct divecomputer *b)
  */
 struct dive *try_to_merge(struct dive *a, struct dive *b, gboolean prefer_downloaded)
 {
-	int offset = 0;
-
 	/*
 	 * This assumes that the clocks on the dive computers are
 	 * roughly synchronized.
 	 */
 	if ((a->when >= b->when + 60) || (a->when <= b->when - 60))
 		return NULL;
-	if (!prefer_downloaded) {
-		/* Dive 'a' is 'offset' seconds before dive 'b' */
-		offset = find_sample_offset(&a->dc, &b->dc);
-		if (offset > 120 || offset < -120)
-			return NULL;
+	return merge_dives(a, b, 0, prefer_downloaded);
+}
+
+static void free_events(struct event *ev)
+{
+	while (ev) {
+		struct event *next = ev->next;
+		free(ev);
+		ev = next;
 	}
-	return merge_dives(a, b, offset, prefer_downloaded);
+}
+
+static void free_dc(struct divecomputer *dc)
+{
+	free(dc->sample);
+	free_events(dc->events);
+	free(dc);
+}
+
+static int same_event(struct event *a, struct event *b)
+{
+	if (a->time.seconds != b->time.seconds)
+		return 0;
+	if (a->type != b->type)
+		return 0;
+	if (a->flags != b->flags)
+		return 0;
+	if (a->value != b->value)
+		return 0;
+	return !strcmp(a->name, b->name);
+}
+
+static int same_sample(struct sample *a, struct sample *b)
+{
+	if (a->time.seconds != b->time.seconds)
+		return 0;
+	if (a->depth.mm != b->depth.mm)
+		return 0;
+	if (a->temperature.mkelvin != b->temperature.mkelvin)
+		return 0;
+	if (a->cylinderpressure.mbar != b->cylinderpressure.mbar)
+		return 0;
+	return a->cylinderindex == b->cylinderindex;
+}
+
+static int same_dc(struct divecomputer *a, struct divecomputer *b)
+{
+	int i;
+	struct event *eva, *evb;
+
+	if (a->when && b->when && a->when != b->when)
+		return 0;
+	if (a->samples != b->samples)
+		return 0;
+	for (i = 0; i < a->samples; i++)
+		if (!same_sample(a->sample+i, b->sample+i))
+			return 0;
+	eva = a->events;
+	evb = b->events;
+	while (eva && evb) {
+		if (!same_event(eva, evb))
+			return 0;
+		eva = eva->next;
+		evb = evb->next;
+	}
+	return eva == evb;
+}
+
+static void remove_redundant_dc(struct divecomputer *dc)
+{
+	do {
+		struct divecomputer **p = &dc->next;
+
+		/* Check this dc against all the following ones.. */
+		while (*p) {
+			struct divecomputer *check = *p;
+			if (same_dc(dc, check)) {
+				*p = check->next;
+				check->next = NULL;
+				free_dc(check);
+				continue;
+			}
+			p = &check->next;
+		}
+
+		/* .. and then continue down the chain */
+		dc = dc->next;
+	} while (dc);
 }
 
 struct dive *merge_dives(struct dive *a, struct dive *b, int offset, gboolean prefer_downloaded)
@@ -1079,7 +1158,7 @@ struct dive *merge_dives(struct dive *a, struct dive *b, int offset, gboolean pr
 		else if (b->downloaded)
 			dl = b;
 	}
-	res->when = a->when;
+	res->when = dl ? dl->when : a->when;
 	res->selected = a->selected || b->selected;
 	merge_trip(res, a, b);
 	MERGE_NONZERO(res, a, b, latitude);
@@ -1110,9 +1189,39 @@ struct dive *merge_dives(struct dive *a, struct dive *b, int offset, gboolean pr
 		 * dive computer data is cleared out.
 		 */
 		memset(&dl->dc, 0, sizeof(dl->dc));
+	} else if (offset) {
+		struct divecomputer *a_dc = &a->dc;
+		struct divecomputer *b_dc = &b->dc;
+		struct divecomputer *res_dc = &res->dc;
+
+		/*
+		 * FIXME! We should try to match these things up some way,
+		 * now we just depend on the merged dives having the same
+		 * dive computers in the same order!
+		 */
+		for (;;) {
+			merge_events(res_dc, a_dc, b_dc, offset);
+			merge_samples(res_dc, a_dc, b_dc, offset);
+			a_dc = a_dc->next;
+			b_dc = b_dc->next;
+			if (!a_dc || !b_dc)
+				break;
+			res_dc->next = calloc(1, sizeof(*res_dc));
+			res_dc = res_dc->next;
+			if (!res_dc)
+				break;
+		}
 	} else {
-		merge_events(&res->dc, &a->dc, &b->dc, offset);
-		merge_samples(&res->dc, &a->dc, &b->dc, offset);
+		struct divecomputer *dc;
+		res->dc = a->dc;
+		memset(&a->dc, 0, sizeof(a->dc));
+		dc = &res->dc;
+		while (dc->next)
+			dc = dc->next;
+		dc->next = calloc(1, sizeof(*dc));
+		*dc->next = b->dc;
+		memset(&b->dc, 0,sizeof(b->dc));
+		remove_redundant_dc(&res->dc);
 	}
 	fixup_dive(res);
 	return res;