feat: init

service/im/util.rs

@@ -0,0 +1,64 @@
+pub use crate::service::util::{
+    clamp_limit_offset, ensure_affected, merge_optional_text, parse_enum, required_text, role_level,
+};
+
+/// Maximum length for a channel name.
+pub const MAX_CHANNEL_NAME: usize = 100;
+
+/// Maximum length for a channel topic.
+pub const MAX_CHANNEL_TOPIC: usize = 1024;
+
+/// Maximum length for a message body.
+pub const MAX_MESSAGE_BODY: usize = 4096;
+
+/// Maximum length for an article title.
+pub const MAX_ARTICLE_TITLE: usize = 256;
+
+/// Maximum number of poll options.
+pub const MAX_POLL_OPTIONS: usize = 10;
+
+/// Maximum length for a poll option text.
+pub const MAX_POLL_OPTION_TEXT: usize = 100;
+
+/// Redis key prefix for typing indicators.
+pub const TYPING_PREFIX: &str = "im:typing:";
+
+/// Redis key prefix for user presence.
+pub const PRESENCE_PREFIX: &str = "im:presence:";
+
+/// Redis TTL for typing indicators (seconds).
+pub const TYPING_TTL_SECS: usize = 8;
+
+/// Redis TTL for presence heartbeats (seconds).
+pub const PRESENCE_TTL_SECS: usize = 120;
+
+/// Maximum length for generated slugs.
+pub const MAX_SLUG_LEN: usize = 128;
+
+/// Generate a slug from a title string.
+pub fn slugify(title: &str) -> String {
+    let slug: String = title
+        .to_lowercase()
+        .chars()
+        .filter_map(|c| {
+            if c.is_ascii_alphanumeric() {
+                Some(c)
+            } else if c.is_whitespace() || !c.is_ascii() {
+                Some('-')
+            } else {
+                None
+            }
+        })
+        .collect::<String>()
+        .split('-')
+        .filter(|s| !s.is_empty())
+        .collect::<Vec<_>>()
+        .join("-");
+
+    let mut result = slug;
+    result.truncate(MAX_SLUG_LEN);
+    if result.ends_with('-') {
+        result.pop();
+    }
+    result
+}