fix: avoid stale claude background wait detection

2 files changed, 88 insertions, 6 deletions

diff --git a/src/detect/agents/claude_code.rs b/src/detect/agents/claude_code.rs
index 0918f5a2..ace946da 100644
--- a/src/detect/agents/claude_code.rs
+++ b/src/detect/agents/claude_code.rs
@@ -107,12 +107,42 @@ fn has_live_blocked_form(content: &str) -> bool {
 }
 
 fn has_background_agent_wait(content_above_prompt: &str) -> bool {
-    content_above_prompt.lines().rev().take(8).any(|line| {
-        let lower = line.to_lowercase();
-        lower.contains("waiting for")
-            && lower.contains("background agent")
-            && lower.contains("to finish")
-    })
+    let Some(line) = content_above_prompt
+        .lines()
+        .rev()
+        .find(|line| !line.trim().is_empty())
+    else {
+        return false;
+    };
+
+    is_background_agent_wait_line(line)
+}
+
+fn is_background_agent_wait_line(line: &str) -> bool {
+    let mut text = line.trim();
+    if !text.starts_with("Waiting for ") && !text.starts_with("waiting for ") {
+        let mut chars = text.chars();
+        let Some(first) = chars.next() else {
+            return false;
+        };
+        if first.is_alphanumeric() {
+            return false;
+        }
+        text = chars.as_str().trim_start();
+    }
+
+    let lower = text.to_ascii_lowercase();
+    let Some(rest) = lower.strip_prefix("waiting for ") else {
+        return false;
+    };
+    let Some((count, rest)) = rest.split_once(' ') else {
+        return false;
+    };
+    if count.parse::<u32>().ok().is_none_or(|count| count == 0) {
+        return false;
+    }
+
+    rest == "background agent to finish" || rest == "background agents to finish"
 }
 
 fn has_claude_yes_no_choice(content: &str) -> bool {
diff --git a/src/detect/mod.rs b/src/detect/mod.rs
index a1084e06..58a73d7d 100644
--- a/src/detect/mod.rs
+++ b/src/detect/mod.rs
@@ -1121,6 +1121,58 @@ mod tests {
     }
 
     #[test]
+    fn claude_waiting_for_multiple_background_agents_is_working() {
+        let screen = "● Done. I’ve delegated two investigations.\n\n✻ Waiting for 2 background agents to finish\n\n─────────────────────────────────────────────────────────────────────────────────────────\n❯ \n─────────────────────────────────────────────────────────────────────────────────────────\n  ~/P/herdr ⎇ master ▱▱▱▱▱ 0%";
+        let detection = detect_agent(Some(Agent::Claude), screen);
+
+        assert_eq!(detection.state, AgentState::Working);
+        assert!(detection.visible_working);
+        assert!(!detection.visible_idle);
+    }
+
+    #[test]
+    fn claude_completed_background_agent_wait_in_scrollback_is_idle() {
+        let screen = "❯ please create a background agent that sleeps 15 sec then say hi\n\n  Thought for 8s (ctrl+o to expand)\n\n● claude(Sleep then say hi)\n  ⎿  Backgrounded agent (↓ to manage · ctrl+o to expand)\n\n● Done. I launched a background agent that will wait 15 seconds and then reply with hi.\n\n✻ Waiting for 1 background agent to finish\n\n● Agent \"Sleep then say hi\" completed · 17s\n\n● hi\n\n✻ Brewed for 28s\n\n─────────────────────────────────────────────────────────────────────────────────────────\n❯ \n─────────────────────────────────────────────────────────────────────────────────────────\n  ~/P/herdr ⎇ master ▱▱▱▱▱ 0%";
+        let detection = detect_agent(Some(Agent::Claude), screen);
+
+        assert_eq!(detection.state, AgentState::Idle);
+        assert!(detection.visible_idle);
+        assert!(!detection.visible_working);
+        assert!(!detection.visible_blocker);
+    }
+
+    #[test]
+    fn claude_completed_background_agent_with_prompt_box_is_idle() {
+        let screen = "● Done. I’ve started a background agent.\n\n✻ Waiting for 1 background agent to finish\n\n⏺ Agent \"Sleep then say hi\" completed · 31s\n\n⏺ hi\n\n✻ Baked for 42s\n\n─────────────────────────────────────────────────────────────────────────────────────────\n❯ \n─────────────────────────────────────────────────────────────────────────────────────────\n  ~/P/herdr ⎇ master ▱▱▱▱▱ 0%\n\n  ● main      ↑/↓ to select · Enter to view\n  ◯ general-purpose  Sleep then say hi  31s";
+        let detection = detect_agent(Some(Agent::Claude), screen);
+
+        assert_eq!(detection.state, AgentState::Idle);
+        assert!(detection.visible_idle);
+        assert!(!detection.visible_working);
+        assert!(!detection.visible_blocker);
+    }
+
+    #[test]
+    fn claude_zero_background_agent_wait_with_prompt_box_is_idle() {
+        let screen = "✻ Waiting for 0 background agents to finish\n\n─────────────────────────────────────────────────────────────────────────────────────────\n❯ \n─────────────────────────────────────────────────────────────────────────────────────────\n  ~/P/herdr ⎇ master ▱▱▱▱▱ 0%";
+        let detection = detect_agent(Some(Agent::Claude), screen);
+
+        assert_eq!(detection.state, AgentState::Idle);
+        assert!(detection.visible_idle);
+        assert!(!detection.visible_working);
+    }
+
+    #[test]
+    fn claude_background_agent_wait_phrase_in_prose_is_idle() {
+        let screen = "Claude mentioned: Waiting for 1 background agent to finish\n\n─────────────────────────────────────────────────────────────────────────────────────────\n❯ \n─────────────────────────────────────────────────────────────────────────────────────────\n  ~/P/herdr ⎇ master ▱▱▱▱▱ 0%";
+        let detection = detect_agent(Some(Agent::Claude), screen);
+
+        assert_eq!(detection.state, AgentState::Idle);
+        assert!(detection.visible_idle);
+        assert!(!detection.visible_working);
+    }
+
+    #[test]
     fn claude_idle_search() {
         let screen = "⌕ Search…\nsome content";
         assert_eq!(detect_claude(screen), AgentState::Idle);