From a3c4c3ea5e6bbf792588dca95a0768bc5ccb7b48 Mon Sep 17 00:00:00 2001
From: John Doty <john@d0ty.me>
Date: Thu, 23 Mar 2023 19:40:42 -0700
Subject: [PATCH] Track the selection across refreshes by port number

The next step would obviously be to track the selection only by port
number, so that we remember the selection if the port goes away and
comes back.
---
 src/client/ui.rs | 99 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 90 insertions(+), 9 deletions(-)

diff --git a/src/client/ui.rs b/src/client/ui.rs
index ec0ac73..9b8363b 100644
--- a/src/client/ui.rs
+++ b/src/client/ui.rs
@@ -537,6 +537,9 @@ impl UI {
                 let mut leftover_ports: HashSet<u16> =
                     HashSet::from_iter(self.ports.keys().copied());
 
+                // Grab the selected port
+                let selected_port = self.get_selected_port();
+
                 for port_desc in p.into_iter() {
                     leftover_ports.remove(&port_desc.port);
                     if let Some(listener) = self.ports.get_mut(&port_desc.port)
@@ -567,14 +570,16 @@ impl UI {
                     }
                 }
 
-                let selected = if self.ports.len() == 0 {
-                    None // No ports, no selection.
-                } else {
-                    match self.selection.selected() {
-                        Some(i) => Some(i.min(self.ports.len() - 1)),
-                        None => Some(0),
+                let selected = match selected_port {
+                    Some(port) => {
+                        match self.get_ui_ports().binary_search(&port) {
+                            Ok(index) => Some(index),
+                            Err(_) => None,
+                        }
                     }
+                    None => None,
                 };
+
                 self.selection.select(selected);
             }
             Some(UIEvent::ServerLine(line)) => {
@@ -670,15 +675,15 @@ mod tests {
         ])));
         ui.selection.select(Some(1));
 
-        // ...but now there is one fewer port, selection should move.
+        // ...but now the port I had selected goes away, my selection should clear.
         ui.handle_internal_event(Some(UIEvent::Ports(vec![PortDesc {
             port: 8080,
             desc: "my-service".to_string(),
         }])));
         assert_eq!(ui.ports.len(), 1);
-        assert_matches!(ui.selection.selected(), Some(0));
+        assert_matches!(ui.selection.selected(), None);
 
-        // Put it back but selection doesn't move
+        // Put it back but we don't re-select it. (Sorry bro?)
         ui.handle_internal_event(Some(UIEvent::Ports(vec![
             PortDesc {
                 port: 8080,
@@ -690,9 +695,85 @@ mod tests {
             },
         ])));
         assert_eq!(ui.ports.len(), 2);
+        assert_matches!(ui.selection.selected(), None);
+
+        // Now, there are ports...
+        ui.handle_internal_event(Some(UIEvent::Ports(vec![
+            PortDesc {
+                port: 8080,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8081,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8082,
+                desc: "my-service".to_string(),
+            },
+        ])));
+
+        // Select the middle one.
+        ui.selection.select(Some(1));
+
+        // Drop the first one, the selection should move up.
+        ui.handle_internal_event(Some(UIEvent::Ports(vec![
+            PortDesc {
+                port: 8081,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8082,
+                desc: "my-service".to_string(),
+            },
+        ])));
         assert_matches!(ui.selection.selected(), Some(0));
 
+        // Insert two at the top, it should move down.
+        ui.handle_internal_event(Some(UIEvent::Ports(vec![
+            PortDesc {
+                port: 8079,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8080,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8081,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8082,
+                desc: "my-service".to_string(),
+            },
+        ])));
+        assert_matches!(ui.selection.selected(), Some(2));
+
+        drop(sender);
+    }
+
+    #[test]
+    fn port_selection_wrapping() {
+        let (sender, receiver) = mpsc::channel(64);
+        let config = ServerConfig::default();
+        let mut ui = UI::new(receiver, config);
+
+        ui.handle_internal_event(Some(UIEvent::Ports(vec![
+            PortDesc {
+                port: 8080,
+                desc: "my-service".to_string(),
+            },
+            PortDesc {
+                port: 8081,
+                desc: "my-service".to_string(),
+            },
+        ])));
+        assert_eq!(ui.ports.len(), 2);
+        assert_matches!(ui.selection.selected(), None);
+
         // Move selection up => wraps around the length
+        ui.selection.select(Some(0));
         ui.handle_console_event(Some(Ok(Event::Key(KeyEvent::new(
             KeyCode::Up,
             KeyModifiers::empty(),