1 files changed, 77 insertions, 0 deletions
diff --git a/tag.c b/tag.c
new file mode 100644
index 0000000..014e84c
--- /dev/null
+++ b/tag.c
@@ -0,0 +1,77 @@
+/* Copyright (C) 2018  Curtis McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <err.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+
+#include "chat.h"
+
+const struct Tag TAG_ALL = { (size_t)-1, NULL };
+const struct Tag TAG_DEFAULT = { 0, "(status)" };
+
+static struct {
+	char *name[TAGS_LEN];
+	size_t len;
+	size_t gap;
+} tags = {
+	.name = { "(status)" },
+	.len = 1,
+	.gap = 1,
+};
+
+static struct Tag Tag(size_t id) {
+	return (struct Tag) { id, tags.name[id] };
+}
+
+struct Tag tagName(const char *name) {
+	for (size_t id = 0; id < tags.len; ++id) {
+		if (!tags.name[id] || strcmp(tags.name[id], name)) continue;
+		return Tag(id);
+	}
+	return TAG_ALL;
+}
+
+struct Tag tagNum(size_t num) {
+	if (num < tags.gap) return Tag(num);
+	num -= tags.gap;
+	for (size_t id = tags.gap; id < tags.len; ++id) {
+		if (!tags.name[id]) continue;
+		if (!num--) return Tag(id);
+	}
+	return TAG_ALL;
+}
+
+struct Tag tagFor(const char *name) {
+	struct Tag tag = tagName(name);
+	if (tag.name) return tag;
+
+	size_t id = tags.gap;
+	tags.name[id] = strdup(name);
+	if (!tags.name[id]) err(EX_OSERR, "strdup");
+
+	if (tags.gap == tags.len) {
+		tags.gap++;
+		tags.len++;
+	} else {
+		for (tags.gap++; tags.gap < tags.len; ++tags.gap) {
+			if (!tags.name[tags.gap]) break;
+		}
+	}
+
+	return Tag(id);
+}