Add dive site data structure

This leaves location and gps coordinates in the struct dive to allow a
step by step migration.

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

divesite.h

@@ -0,0 +1,47 @@
+#ifndef DIVESITE_H
+#define DIVESITE_H
+
+#include "units.h"
+#include <stdlib.h>
+
+struct dive_site
+{
+	uint32_t uuid;
+	char *name;
+	degrees_t latitude, longitude;
+	char *description;
+	char *notes;
+};
+
+struct dive_site_table {
+	int nr, allocated;
+	struct dive_site **dive_sites;
+};
+
+extern struct dive_site_table dive_site_table;
+
+static inline struct dive_site *get_dive_site(int nr)
+{
+	if (nr >= dive_site_table.nr || nr < 0)
+		return NULL;
+	return dive_site_table.dive_sites[nr];
+}
+
+static inline struct dive_site *get_dive_site_by_uuid(uint32_t uuid)
+{
+	for (int i = 0; i < dive_site_table.nr; i++)
+		if (get_dive_site(i)->uuid == uuid)
+			return get_dive_site(i);
+	return NULL;
+}
+
+/* there could be multiple sites of the same name - return the first one */
+static inline struct dive_site *get_dive_site_by_name(const char *name)
+{
+	for (int i = 0; i < dive_site_table.nr; i++)
+		if (get_dive_site(i)->name == name)
+			return get_dive_site(i);
+	return NULL;
+}
+
+#endif // DIVESITE_H