Populate completion with commands

1 files changed, 110 insertions, 0 deletions

diff --git a/complete.c b/complete.c
new file mode 100644
index 0000000..b8f2dfc
--- /dev/null
+++ b/complete.c
@@ -0,0 +1,110 @@
+/* Copyright (C) 2020  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <err.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sysexits.h>
+
+#include "chat.h"
+
+struct Node {
+	size_t id;
+	char *str;
+	enum Color color;
+	struct Node *prev;
+	struct Node *next;
+};
+
+static struct Node *alloc(size_t id, const char *str, enum Color color) {
+	struct Node *node = malloc(sizeof(*node));
+	if (!node) err(EX_OSERR, "malloc");
+	node->id = id;
+	node->str = strdup(str);
+	if (!node->str) err(EX_OSERR, "strdup");
+	node->color = color;
+	node->prev = NULL;
+	node->next = NULL;
+	return node;
+}
+
+static struct Node *head;
+static struct Node *tail;
+
+static struct Node *detach(struct Node *node) {
+	if (node->prev) node->prev->next = node->next;
+	if (node->next) node->next->prev = node->prev;
+	if (head == node) head = node->next;
+	if (tail == node) tail = node->prev;
+	node->prev = NULL;
+	node->next = NULL;
+	return node;
+}
+
+static struct Node *prepend(struct Node *node) {
+	node->prev = NULL;
+	node->next = head;
+	if (head) head->prev = node;
+	head = node;
+	if (!tail) tail = node;
+	return node;
+}
+
+static struct Node *append(struct Node *node) {
+	node->next = NULL;
+	node->prev = tail;
+	if (tail) tail->next = node;
+	tail = node;
+	if (!head) head = node;
+	return node;
+}
+
+static struct Node *find(size_t id, const char *str) {
+	for (struct Node *node = head; node; node = node->next) {
+		if (node->id == id && !strcmp(node->str, str)) return node;
+	}
+	return NULL;
+}
+
+void completeAdd(size_t id, const char *str, enum Color color) {
+	if (!find(id, str)) append(alloc(id, str, color));
+}
+
+void completeTouch(size_t id, const char *str, enum Color color) {
+	struct Node *node = find(id, str);
+	prepend(node ? detach(node) : alloc(id, str, color));
+}
+
+static struct Node *match;
+
+const char *complete(size_t id, const char *prefix) {
+	for (match = (match ? match->next : head); match; match = match->next) {
+		if (match->id && match->id != id) continue;
+		if (strncasecmp(match->str, prefix, strlen(prefix))) continue;
+		return match->str;
+	}
+	return NULL;
+}
+
+void completeAccept(void) {
+	if (match) prepend(detach(match));
+	match = NULL;
+}
+
+void completeReject(void) {
+	match = NULL;
+}