feat(tui): wrap long chat messages instead of clipping them

soulseek-rs/src/ui/utils.rs

@@ -30,9 +30,68 @@ pub fn format_speed(speed_bytes_per_sec: f64) -> String {
     format!("{mb:.1} MB/s")
 }
 
+/// Wrap a chat message into display lines: the prefix spans (time, sender)
+/// start the first line, and continuation lines are indented to the prefix
+/// width so the message text stays column-aligned.
+// ponytail: char-count wrap; wide glyphs may spill a cell — switch to
+// unicode-width if that ever matters.
+pub fn wrap_chat_line(
+    prefix: Vec<Span<'static>>,
+    text: &str,
+    style: Style,
+    width: usize,
+) -> Vec<Line<'static>> {
+    let prefix_width: usize = prefix.iter().map(Span::width).sum();
+    let avail = width.saturating_sub(prefix_width).max(1);
+    let chars: Vec<char> = text.chars().collect();
+    let indent = " ".repeat(prefix_width);
+
+    let mut lines = Vec::new();
+    let mut i = 0;
+    loop {
+        let chunk: String = chars[i..].iter().take(avail).collect();
+        let spans = if i == 0 {
+            let mut spans = prefix.clone();
+            spans.push(Span::styled(chunk, style));
+            spans
+        } else {
+            vec![Span::raw(indent.clone()), Span::styled(chunk, style)]
+        };
+        lines.push(Line::from(spans));
+        i += avail;
+        if i >= chars.len() {
+            return lines;
+        }
+    }
+}
+
 const SPINNER_CHARS: [&str; 10] =
     ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];
 
 pub const fn get_spinner_char(state: usize) -> &'static str {
     SPINNER_CHARS[state % SPINNER_CHARS.len()]
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn wrap_chat_line_wraps_and_indents() {
+        let prefix = vec![Span::raw("12:00 "), Span::raw("<bob> ")];
+        let lines =
+            wrap_chat_line(prefix, "abcdefghij", Style::default(), 16);
+        // prefix width 12, so 4 text chars per row.
+        assert_eq!(lines.len(), 3);
+        assert_eq!(lines[0].to_string(), "12:00 <bob> abcd");
+        assert_eq!(lines[1].to_string(), "            efgh");
+        assert_eq!(lines[2].to_string(), "            ij");
+    }
+
+    #[test]
+    fn wrap_chat_line_short_message_is_one_line() {
+        let lines =
+            wrap_chat_line(vec![Span::raw("x ")], "hi", Style::default(), 80);
+        assert_eq!(lines.len(), 1);
+    }
+}