core: add get_or_add helper for dc table

This makes it much easier to manipulate dc nickname entries. In order
for that to work we can't simply remove entries with empty nickname (but
that isn't needed, anyway, as the code that saves XML or git already
handles that case correctly).

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

2 files changed, 13 insertions, 7 deletions

diff --git a/core/device.cpp b/core/device.cpp
index 42c2be004..a01893f60 100644
--- a/core/device.cpp
+++ b/core/device.cpp
@@ -44,6 +44,18 @@ extern "C" const struct device *get_device_for_dc(const struct device_table *tab
 	return it != dcs.end() && same_device(*it, dev) ? &*it : NULL;
 }
 
+extern "C" int get_or_add_device_for_dc(struct device_table *table, const struct divecomputer *dc)
+{
+	if (!dc->model || !dc->serial)
+		return -1;
+	const struct device *dev = get_device_for_dc(table, dc);
+	if (dev) {
+		auto it = std::lower_bound(table->devices.begin(), table->devices.end(), *dev);
+		return it - table->devices.begin();
+	}
+	return create_device_node(table, dc->model, dc->serial, "");
+}
+
 extern "C" bool device_exists(const struct device_table *device_table, const struct device *dev)
 {
 	auto it = std::lower_bound(device_table->devices.begin(), device_table->devices.end(), *dev);
@@ -71,16 +83,9 @@ static int addDC(std::vector<device> &dcs, const std::string &m, const std::stri
 		if (verbose)
 			it->showchanges(n);
 		// Update any non-existent fields from the old entry
-		if (n.empty()) {
-			dcs.erase(it);
-			return -1;
-		}
 		it->nickName = n;
 		return it - dcs.begin();
 	} else {
-		if (n.empty())
-			return -1;
-
 		dev.deviceId = calculate_string_hash(s.c_str());
 		dcs.insert(it, dev);
 		return it - dcs.begin();
diff --git a/core/device.h b/core/device.h
index 6bfb85e3c..9e0a90ac9 100644
--- a/core/device.h
+++ b/core/device.h
@@ -25,6 +25,7 @@ const char *get_dc_nickname(const struct divecomputer *dc);
 extern bool device_used_by_selected_dive(const struct device *dev);
 
 extern const struct device *get_device_for_dc(const struct device_table *table, const struct divecomputer *dc);
+extern int get_or_add_device_for_dc(struct device_table *table, const struct divecomputer *dc);
 extern bool device_exists(const struct device_table *table, const struct device *dev);
 extern int add_to_device_table(struct device_table *table, const struct device *dev); // returns index
 extern int remove_device(struct device_table *table, const struct device *dev); // returns index or -1 if not found