Improve translation prompt and add /trans off toggle

- Focus on grammar/sentence structure for language detection
- Ignore code, URLs, tech jargon in language classification
- /trans cycles: local → public → off
- Strip trailing whitespace from LLM responses
- Suppress empty translation results

main.c

@@ -78,6 +78,7 @@ static struct {
 /* Query target (for /q) */
 static char query_target[64] = "";
 static int translate_public = 0; /* /trans toggle: echo translations to channel */
+static int translate_enabled = 1; /* master toggle for translation */
 
 /* Track nicks who sent us private messages */
 #define MAX_PM_NICKS 32
@@ -186,7 +187,7 @@ static void ai_config_load(void)
 
 static int needs_translation(const char *text)
 {
-	if (!ai_cfg.enabled) return 0;
+	if (!ai_cfg.enabled || !translate_enabled) return 0;
 	/* Skip very short messages (nicks, URLs, single words like "ok") */
 	int words = 0;
 	for (const char *p = text; *p; p++)
@@ -241,7 +242,7 @@ static void translate_async(const char *text, int level, const char *target)
 		char body[2048];
 		snprintf(body, sizeof(body),
 			"{\"model\":\"%s\",\"messages\":["
-			"{\"role\":\"system\",\"content\":\"You are a translator for an IRC chat. The user understands %s. If the message is in any of those languages or a mix of them, respond with exactly SKIP. Only translate messages in other languages to %s. Respond with only the translation or SKIP.\"},"
+			"{\"role\":\"system\",\"content\":\"You are a language filter for IRC. Respond with ONLY the word SKIP or a translation. Rules: If the sentence structure and grammar is %s, respond SKIP. Code snippets, function names, URLs, and technical jargon inside a sentence do NOT change the language. Only translate if the grammar itself is in another language. Translate to %s.\"},"
 			"{\"role\":\"user\",\"content\":\"%s\"}"
 			"],\"stream\":false,\"tool_choice\":\"none\"}",
 			ai_cfg.model, ai_cfg.skip_langs, ai_cfg.target_lang, escaped);
@@ -1188,9 +1189,18 @@ static void handle_input(char *line)
 				wprintf(WL_MSG, "* %s %s\n", nick, slap);
 			}
 		} else if (strcasecmp(cmd, "trans") == 0) {
-			translate_public = !translate_public;
+			if (!translate_enabled) {
-			wprintf(current_level, "* Translation echo %s\n",
+				translate_enabled = 1;
-			        translate_public ? "ON" : "OFF");
+				translate_public = 0;
+				wprintf(current_level, "* Translation ON (local only)\n");
+			} else if (!translate_public) {
+				translate_public = 1;
+				wprintf(current_level, "* Translation ON (public echo)\n");
+			} else {
+				translate_enabled = 0;
+				translate_public = 0;
+				wprintf(current_level, "* Translation OFF\n");
+			}
 		} else if (strcasecmp(cmd, "ctcp") == 0 && args) {
 			char *target = args;
 			char *ctcp_cmd = strchr(args, ' ');
@@ -1473,8 +1483,12 @@ int main(int argc, char *argv[])
 				waitpid(translate_pending[ti].pid, NULL, 0);
 				if (n > 0) {
 					tbuf[n] = '\0';
+					/* Strip trailing whitespace */
+					while (n > 0 && (tbuf[n-1] == '\n' || tbuf[n-1] == '\r' || tbuf[n-1] == ' '))
+						tbuf[--n] = '\0';
 					/* Skip if LLM says it's already in a skip language */
-					if (strcasecmp(tbuf, "SKIP") == 0 ||
+					if (n == 0 ||
+					    strcasecmp(tbuf, "SKIP") == 0 ||
 					    strncasecmp(tbuf, "SKIP", 4) == 0) {
 						/* do nothing */
 					} else {