feat(plugins): add API to list clients, their focused panes and running commands/plugins (#3687)

* fix(list-clients): properly show client info after a tab was closed

* feat(plugins): add API to list clients, their focused panes and running commands/plugins

* style(fmt): rustfmt

4 files changed, 84 insertions, 11 deletions

diff --git a/zellij-utils/src/plugin_api/event.proto b/zellij-utils/src/plugin_api/event.proto
index e3f3cacb..607ba448 100644
--- a/zellij-utils/src/plugin_api/event.proto
+++ b/zellij-utils/src/plugin_api/event.proto
@@ -49,6 +49,7 @@ enum EventType {
     EditPaneExited = 23;
     CommandPaneReRun = 24;
     FailedToWriteConfigToDisk = 25;
+    ListClients = 26;
 }
 
 message EventNameList {
@@ -79,9 +80,21 @@ message Event {
     EditPaneExitedPayload edit_pane_exited_payload = 20;
     CommandPaneReRunPayload command_pane_rerun_payload = 21;
     FailedToWriteConfigToDiskPayload failed_to_write_config_to_disk_payload = 22;
+    ListClientsPayload list_clients_payload = 23;
   }
 }
 
+message ListClientsPayload {
+  repeated ClientInfo client_info = 1;
+}
+
+message ClientInfo {
+  uint32 client_id = 1;
+  PaneId pane_id = 2;
+  string running_command = 3;
+  bool is_current_client = 4;
+}
+
 message FailedToWriteConfigToDiskPayload {
   optional string file_path = 1;
 }
diff --git a/zellij-utils/src/plugin_api/event.rs b/zellij-utils/src/plugin_api/event.rs
index d1e2f50d..d78f5567 100644
--- a/zellij-utils/src/plugin_api/event.rs
+++ b/zellij-utils/src/plugin_api/event.rs
@@ -1,14 +1,15 @@
 pub use super::generated_api::api::{
     action::{Action as ProtobufAction, Position as ProtobufPosition},
     event::{
-        event::Payload as ProtobufEventPayload, CopyDestination as ProtobufCopyDestination,
-        Event as ProtobufEvent, EventNameList as ProtobufEventNameList,
-        EventType as ProtobufEventType, FileMetadata as ProtobufFileMetadata,
-        InputModeKeybinds as ProtobufInputModeKeybinds, KeyBind as ProtobufKeyBind,
-        LayoutInfo as ProtobufLayoutInfo, ModeUpdatePayload as ProtobufModeUpdatePayload,
-        PaneId as ProtobufPaneId, PaneInfo as ProtobufPaneInfo,
-        PaneManifest as ProtobufPaneManifest, PaneType as ProtobufPaneType,
-        PluginInfo as ProtobufPluginInfo, ResurrectableSession as ProtobufResurrectableSession,
+        event::Payload as ProtobufEventPayload, ClientInfo as ProtobufClientInfo,
+        CopyDestination as ProtobufCopyDestination, Event as ProtobufEvent,
+        EventNameList as ProtobufEventNameList, EventType as ProtobufEventType,
+        FileMetadata as ProtobufFileMetadata, InputModeKeybinds as ProtobufInputModeKeybinds,
+        KeyBind as ProtobufKeyBind, LayoutInfo as ProtobufLayoutInfo,
+        ModeUpdatePayload as ProtobufModeUpdatePayload, PaneId as ProtobufPaneId,
+        PaneInfo as ProtobufPaneInfo, PaneManifest as ProtobufPaneManifest,
+        PaneType as ProtobufPaneType, PluginInfo as ProtobufPluginInfo,
+        ResurrectableSession as ProtobufResurrectableSession,
         SessionManifest as ProtobufSessionManifest, TabInfo as ProtobufTabInfo, *,
     },
     input_mode::InputMode as ProtobufInputMode,
@@ -17,9 +18,9 @@ pub use super::generated_api::api::{
 };
 #[allow(hidden_glob_reexports)]
 use crate::data::{
-    CopyDestination, Event, EventType, FileMetadata, InputMode, KeyWithModifier, LayoutInfo,
-    ModeInfo, Mouse, PaneId, PaneInfo, PaneManifest, PermissionStatus, PluginCapabilities,
-    PluginInfo, SessionInfo, Style, TabInfo,
+    ClientInfo, CopyDestination, Event, EventType, FileMetadata, InputMode, KeyWithModifier,
+    LayoutInfo, ModeInfo, Mouse, PaneId, PaneInfo, PaneManifest, PermissionStatus,
+    PluginCapabilities, PluginInfo, SessionInfo, Style, TabInfo,
 };
 
 use crate::errors::prelude::*;
@@ -320,11 +321,50 @@ impl TryFrom<ProtobufEvent> for Event {
                 )),
                 _ => Err("Malformed payload for the FailedToWriteConfigToDisk Event"),
             },
+            Some(ProtobufEventType::ListClients) => match protobuf_event.payload {
+                Some(ProtobufEventPayload::ListClientsPayload(mut list_clients_payload)) => {
+                    Ok(Event::ListClients(
+                        list_clients_payload
+                            .client_info
+                            .drain(..)
+                            .filter_map(|c| c.try_into().ok())
+                            .collect(),
+                    ))
+                },
+                _ => Err("Malformed payload for the FailedToWriteConfigToDisk Event"),
+            },
             None => Err("Unknown Protobuf Event"),
         }
     }
 }
 
+impl TryFrom<ProtobufClientInfo> for ClientInfo {
+    type Error = &'static str;
+    fn try_from(protobuf_client_info: ProtobufClientInfo) -> Result<Self, &'static str> {
+        Ok(ClientInfo::new(
+            protobuf_client_info.client_id as u16,
+            protobuf_client_info
+                .pane_id
+                .ok_or("No pane id found")?
+                .try_into()?,
+            protobuf_client_info.running_command,
+            protobuf_client_info.is_current_client,
+        ))
+    }
+}
+
+impl TryFrom<ClientInfo> for ProtobufClientInfo {
+    type Error = &'static str;
+    fn try_from(client_info: ClientInfo) -> Result<Self, &'static str> {
+        Ok(ProtobufClientInfo {
+            client_id: client_info.client_id as u32,
+            pane_id: Some(client_info.pane_id.try_into()?),
+            running_command: client_info.running_command,
+            is_current_client: client_info.is_current_client,
+        })
+    }
+}
+
 impl TryFrom<Event> for ProtobufEvent {
     type Error = &'static str;
     fn try_from(event: Event) -> Result<Self, &'static str> {
@@ -634,6 +674,15 @@ impl TryFrom<Event> for ProtobufEvent {
                     FailedToWriteConfigToDiskPayload { file_path },
                 )),
             }),
+            Event::ListClients(mut client_info_list) => Ok(ProtobufEvent {
+                name: ProtobufEventType::ListClients as i32,
+                payload: Some(event::Payload::ListClientsPayload(ListClientsPayload {
+                    client_info: client_info_list
+                        .drain(..)
+                        .filter_map(|c| c.try_into().ok())
+                        .collect(),
+                })),
+            }),
         }
     }
 }
@@ -1178,6 +1227,7 @@ impl TryFrom<ProtobufEventType> for EventType {
             ProtobufEventType::EditPaneExited => EventType::EditPaneExited,
             ProtobufEventType::CommandPaneReRun => EventType::CommandPaneReRun,
             ProtobufEventType::FailedToWriteConfigToDisk => EventType::FailedToWriteConfigToDisk,
+            ProtobufEventType::ListClients => EventType::ListClients,
         })
     }
 }
@@ -1212,6 +1262,7 @@ impl TryFrom<EventType> for ProtobufEventType {
             EventType::EditPaneExited => ProtobufEventType::EditPaneExited,
             EventType::CommandPaneReRun => ProtobufEventType::CommandPaneReRun,
             EventType::FailedToWriteConfigToDisk => ProtobufEventType::FailedToWriteConfigToDisk,
+            EventType::ListClients => ProtobufEventType::ListClients,
         })
     }
 }
diff --git a/zellij-utils/src/plugin_api/plugin_command.proto b/zellij-utils/src/plugin_api/plugin_command.proto
index 29ebca67..5b58de14 100644
--- a/zellij-utils/src/plugin_api/plugin_command.proto
+++ b/zellij-utils/src/plugin_api/plugin_command.proto
@@ -126,6 +126,7 @@ enum CommandName {
   ReloadPlugin = 110;
   LoadNewPlugin = 111;
   RebindKeys = 112;
+  ListClients = 113;
 }
 
 message PluginCommand {
diff --git a/zellij-utils/src/plugin_api/plugin_command.rs b/zellij-utils/src/plugin_api/plugin_command.rs
index 79b08794..06687971 100644
--- a/zellij-utils/src/plugin_api/plugin_command.rs
+++ b/zellij-utils/src/plugin_api/plugin_command.rs
@@ -1299,6 +1299,10 @@ impl TryFrom<ProtobufPluginCommand> for PluginCommand {
                 },
                 _ => Err("Mismatched payload for RebindKeys"),
             },
+            Some(CommandName::ListClients) => match protobuf_plugin_command.payload {
+                Some(_) => Err("ListClients should have no payload, found a payload"),
+                None => Ok(PluginCommand::ListClients),
+            },
             None => Err("Unrecognized plugin command"),
         }
     }
@@ -2122,6 +2126,10 @@ impl TryFrom<PluginCommand> for ProtobufPluginCommand {
                     write_config_to_disk,
                 })),
             }),
+            PluginCommand::ListClients => Ok(ProtobufPluginCommand {
+                name: CommandName::ListClients as i32,
+                payload: None,
+            }),
         }
     }
 }