configurable max name/message length (0 for unlimited)

module.nix

@@ -51,6 +51,18 @@ in
       description = "Enable honeypot field for spam prevention.";
     };
 
+    maxNameLength = mkOption {
+      type = types.int;
+      default = 50;
+      description = "Maximum length for names. 0 for unlimited.";
+    };
+
+    maxMessageLength = mkOption {
+      type = types.int;
+      default = 1000;
+      description = "Maximum length for messages. 0 for unlimited.";
+    };
+
     user = mkOption {
       type = types.str;
       default = "guestbook";
@@ -87,6 +99,8 @@ in
           BOOK_SITE_URL = cfg.siteUrl;
           BOOK_TELEGRAM_CHAT_ID = toString cfg.telegramChatId;
           BOOK_HONEYPOT = if cfg.honeypot then "true" else "false";
+          BOOK_MAX_NAME_LENGTH = toString cfg.maxNameLength;
+          BOOK_MAX_MESSAGE_LENGTH = toString cfg.maxMessageLength;
         };
         serviceConfig = {
           Type = "simple";

src/config.rs

@@ -10,6 +10,8 @@ pub struct Config {
     pub telegram_bot_token: String,
     pub telegram_chat_id: i64,
     pub honeypot: bool,
+    pub max_name_length: usize,
+    pub max_message_length: usize,
 }
 
 impl Config {
@@ -37,6 +39,14 @@ impl Config {
             honeypot: env::var("BOOK_HONEYPOT")
                 .map(|v| v != "false")
                 .unwrap_or(true),
+            max_name_length: env::var("BOOK_MAX_NAME_LENGTH")
+                .unwrap_or_else(|_| "50".into())
+                .parse()
+                .map_err(|_| "BOOK_MAX_NAME_LENGTH must be a number")?,
+            max_message_length: env::var("BOOK_MAX_MESSAGE_LENGTH")
+                .unwrap_or_else(|_| "1000".into())
+                .parse()
+                .map_err(|_| "BOOK_MAX_MESSAGE_LENGTH must be a number")?,
         })
     }
 }

src/web.rs

@@ -65,14 +65,16 @@ async fn submit(
     if name.is_empty() || message.is_empty() {
         return Html("Name and message are required.".to_string());
     }
-    if name.len() > 50 {
-        return Html("Name is too long (max 50 chars).".to_string());
+    let max_name = state.config.max_name_length;
+    if max_name > 0 && name.len() > max_name {
+        return Html(format!("Name is too long (max {max_name} chars)."));
     }
     if website.len() > 100 {
         return Html("Website is too long (max 100 chars).".to_string());
     }
-    if message.len() > 1000 {
-        return Html("Message is too long (max 1000 chars).".to_string());
+    let max_msg = state.config.max_message_length;
+    if max_msg > 0 && message.len() > max_msg {
+        return Html(format!("Message is too long (max {max_msg} chars)."));
     }
 
     let short_id = &Uuid::new_v4().to_string()[..8];