sample main loops for ogg manipulation

linking now breaks because the ogg module isn't implemented

src/actions.cc

@@ -0,0 +1,56 @@
+#include "ogg.h"
+
+// Here we're going to illustrate how to use the ogg module.
+
+using namespace opustags;
+
+enum StreamSelection {
+	ALL_STREAMS = -1,
+	FIRST_STREAM = -2,
+};
+
+void list_tags(ogg::Reader *reader, long select)
+{
+	ogg::Stream *s;
+	while ((s = reader->read_page()) != NULL) {
+		if (s->state == ogg::TAGS_READY && (select == ALL_STREAMS || select == FIRST_STREAM || s->stream.serialno == select)) {
+			// print_tags(s->tags);
+			if (select != ALL_STREAMS)
+				break;
+		}
+	}
+}
+
+void delete_tags(ogg::Reader *reader, opustags::ogg::Writer *writer, long select)
+{
+	ogg::Stream *s;
+	while ((s = reader->read_page()) != NULL) {
+		switch (s->state) {
+		case ogg::HEADER_READY:
+			// TODO what if select == FIRST_STREAM?
+			if (select != ALL_STREAMS && s->stream.serialno != select)
+				// act like nothing happened and copy this "unknown" stream identically
+				s->type = ogg::UNKNOWN_STREAM;
+			// fall through
+		case ogg::RAW_READY:
+			writer->write_raw_page(s->current_page);
+			break;
+		case ogg::TAGS_READY:
+			// only streams selected at HEADER_READY reach this point
+			writer->write_tags(s->stream.serialno, ogg::Tags());
+			break;
+		case ogg::DATA_READY:
+			writer->write_page(s->current_page);
+			break;
+		default:
+			;
+		}
+	}
+}
+
+// To write edit_tags, we're gonna need something like the options structure in
+// order to know what to do exactly.
+
+// The command-line interface has yet to be done, but it'd be nice it let the
+// user edit several streams at once, like :
+// $ opustags --stream 1 --set TITLE=Foo --stream 2 --set TITLE=Bar

src/ogg.h

@@ -5,7 +5,8 @@
 #include <map>
 #include <ogg/ogg.h>
 
-namespace opustags::ogg
+namespace opustags {
+namespace ogg
 {
     typedef std::map<std::string, std::string> Tags;
 
@@ -89,3 +90,4 @@ namespace opustags::ogg
         std::map<int, ogg_stream_state> streams;
     };
 }
+}