From 0e03c4d21619d9583e5c3d8d0e2797a4b45804e7 Mon Sep 17 00:00:00 2001
From: m1ngsama <contact@m1ng.space>
Date: Sun, 17 May 2026 14:13:21 +0800
Subject: [PATCH] commands: highlight matched keyword in :search results (UX-7)
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:search dumps the matching lines with username and content, but the
query word itself was just rendered as-is.  In a result set with 15
matches you had to eye-scan each line for the keyword.

Now each occurrence of the (case-insensitively matched) needle is
wrapped in a reverse-yellow ANSI chip both in the username column and
in the content column.  Original casing of the matched substring is
preserved.

Helper:
    append_highlighted(output, buf_size, &pos, text, needle)
emits text into the output buffer with every case-insensitive hit
wrapped in `\033[7;33m … \033[0m`.

strcasestr() needs _DEFAULT_SOURCE / _DARWIN_C_SOURCE feature macros;
the same dance message.c already does is now mirrored in commands.c.
---
 src/commands.c | 41 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/commands.c b/src/commands.c
index 1fe3726..641c52f 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -1,3 +1,9 @@
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE  /* for strcasestr() on glibc */
+#endif
+#if defined(__APPLE__) && !defined(_DARWIN_C_SOURCE)
+#define _DARWIN_C_SOURCE /* for strcasestr() on macOS */
+#endif
 #include "commands.h"
 #include "chat_room.h"
 #include "client.h"
@@ -10,6 +16,33 @@
 #include <string.h>
 #include <time.h>
 
+/* Append `text` to the output buffer with every case-insensitive match of
+ * `needle` wrapped in a reverse-yellow ANSI chip.  Preserves the original
+ * casing of the matched substring.  needle == NULL or empty appends raw. */
+static void append_highlighted(char *output, size_t buf_size, size_t *pos,
+                               const char *text, const char *needle) {
+    if (!needle || !*needle) {
+        buffer_appendf(output, buf_size, pos, "%s", text);
+        return;
+    }
+    size_t nlen = strlen(needle);
+    const char *p = text;
+    while (*p) {
+        const char *hit = strcasestr(p, needle);
+        if (!hit) {
+            buffer_appendf(output, buf_size, pos, "%s", p);
+            return;
+        }
+        if (hit > p) {
+            buffer_append_bytes(output, buf_size, pos, p, (size_t)(hit - p));
+        }
+        buffer_append_bytes(output, buf_size, pos, "\033[7;33m", 7);
+        buffer_append_bytes(output, buf_size, pos, hit, nlen);
+        buffer_append_bytes(output, buf_size, pos, "\033[0m", 4);
+        p = hit + nlen;
+    }
+}
+
 void commands_dispatch(client_t *client) {
     char cmd_buf[256];
     strncpy(cmd_buf, client->command_input, sizeof(cmd_buf) - 1);
@@ -253,7 +286,13 @@ void commands_dispatch(client_t *client) {
                 localtime_r(&found[i].timestamp, &tmi);
                 strftime(ts, sizeof(ts), "%m-%d %H:%M", &tmi);
                 buffer_appendf(output, sizeof(output), &pos,
-                               "[%s] %s: %s\n", ts, found[i].username, found[i].content);
+                               "[%s] ", ts);
+                append_highlighted(output, sizeof(output), &pos,
+                                   found[i].username, query);
+                buffer_appendf(output, sizeof(output), &pos, ": ");
+                append_highlighted(output, sizeof(output), &pos,
+                                   found[i].content, query);
+                buffer_appendf(output, sizeof(output), &pos, "\n");
             }
             free(found);
         }