feat(plugins): add tab history to the `SessionUpdate` Event (#4014)

* feat(plugins): add tab-history to the SessionInfo

* update snapshots

* style(fmt): rustfmt

* update changelog

9 files changed, 106 insertions, 10 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61c20420..dcdae5fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * fix(clipboard): various clipboard message fixes (https://github.com/zellij-org/zellij/pull/4009)
 * fix(logging): fix segfault in chrono crate (https://github.com/zellij-org/zellij/pull/4010)
 * fix(floating-panes): reset damage in swap layouts when closing the last pane (https://github.com/zellij-org/zellij/pull/4012)
+* feat(plugins): add tab_history to the session metadata (https://github.com/zellij-org/zellij/pull/4014)
 
 ## [0.41.2] - 2024-11-19
 * fix(input): keypresses not being identified properly with kitty keyboard protocol in some terminals (https://github.com/zellij-org/zellij/pull/3725)
diff --git a/zellij-server/src/screen.rs b/zellij-server/src/screen.rs
index 0b9d0c67..16cc3d39 100644
--- a/zellij-server/src/screen.rs
+++ b/zellij-server/src/screen.rs
@@ -1648,6 +1648,7 @@ impl Screen {
             is_current_session: true,
             available_layouts,
             plugins: Default::default(), // these are filled in by the wasm thread
+            tab_history: self.tab_history.clone(),
         };
         self.bus
             .senders
diff --git a/zellij-utils/assets/prost/api.event.rs b/zellij-utils/assets/prost/api.event.rs
index 493e0dc4..46372db5 100644
--- a/zellij-utils/assets/prost/api.event.rs
+++ b/zellij-utils/assets/prost/api.event.rs
@@ -316,6 +316,16 @@ pub struct SessionManifest {
     pub available_layouts: ::prost::alloc::vec::Vec<LayoutInfo>,
     #[prost(message, repeated, tag = "7")]
     pub plugins: ::prost::alloc::vec::Vec<PluginInfo>,
+    #[prost(message, repeated, tag = "8")]
+    pub tab_history: ::prost::alloc::vec::Vec<ClientTabHistory>,
+}
+#[allow(clippy::derive_partial_eq_without_eq)]
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct ClientTabHistory {
+    #[prost(uint32, tag = "1")]
+    pub client_id: u32,
+    #[prost(uint32, repeated, tag = "2")]
+    pub tab_history: ::prost::alloc::vec::Vec<u32>,
 }
 #[allow(clippy::derive_partial_eq_without_eq)]
 #[derive(Clone, PartialEq, ::prost::Message)]
diff --git a/zellij-utils/src/data.rs b/zellij-utils/src/data.rs
index a1be6274..368b3e2a 100644
--- a/zellij-utils/src/data.rs
+++ b/zellij-utils/src/data.rs
@@ -1554,6 +1554,7 @@ pub struct SessionInfo {
     pub is_current_session: bool,
     pub available_layouts: Vec<LayoutInfo>,
     pub plugins: BTreeMap<u32, PluginInfo>,
+    pub tab_history: BTreeMap<ClientId, Vec<usize>>,
 }
 
 #[derive(Debug, Default, Clone, PartialEq, Eq, Deserialize, Serialize)]
diff --git a/zellij-utils/src/kdl/mod.rs b/zellij-utils/src/kdl/mod.rs
index 27230c2f..93b111f4 100644
--- a/zellij-utils/src/kdl/mod.rs
+++ b/zellij-utils/src/kdl/mod.rs
@@ -4462,6 +4462,29 @@ impl SessionInfo {
             })
             .ok_or("Failed to parse available_layouts")?;
         let is_current_session = name == current_session_name;
+        let mut tab_history = BTreeMap::new();
+        if let Some(kdl_tab_history) = kdl_document.get("tab_history").and_then(|p| p.children()) {
+            for client_node in kdl_tab_history.nodes() {
+                if let Some(client_id) = client_node.children().and_then(|c| {
+                    c.get("id")
+                        .and_then(|c| c.entries().iter().next().and_then(|e| e.value().as_i64()))
+                }) {
+                    let mut history = vec![];
+                    if let Some(history_entries) = client_node
+                        .children()
+                        .and_then(|c| c.get("history"))
+                        .map(|h| h.entries())
+                    {
+                        for entry in history_entries {
+                            if let Some(entry) = entry.value().as_i64() {
+                                history.push(entry as usize);
+                            }
+                        }
+                    }
+                    tab_history.insert(client_id as u16, history);
+                }
+            }
+        }
         Ok(SessionInfo {
             name,
             tabs,
@@ -4470,6 +4493,7 @@ impl SessionInfo {
             is_current_session,
             available_layouts,
             plugins: Default::default(), // we do not serialize plugin information
+            tab_history,
         })
     }
     pub fn to_string(&self) -> String {
@@ -4510,11 +4534,30 @@ impl SessionInfo {
         }
         available_layouts.set_children(available_layouts_children);
 
+        let mut tab_history = KdlNode::new("tab_history");
+        let mut tab_history_children = KdlDocument::new();
+        for (client_id, client_tab_history) in &self.tab_history {
+            let mut client_document = KdlDocument::new();
+            let mut client_node = KdlNode::new("client");
+            let mut id = KdlNode::new("id");
+            id.push(*client_id as i64);
+            client_document.nodes_mut().push(id);
+            let mut history = KdlNode::new("history");
+            for entry in client_tab_history {
+                history.push(*entry as i64);
+            }
+            client_document.nodes_mut().push(history);
+            client_node.set_children(client_document);
+            tab_history_children.nodes_mut().push(client_node);
+        }
+        tab_history.set_children(tab_history_children);
+
         kdl_document.nodes_mut().push(name);
         kdl_document.nodes_mut().push(tabs);
         kdl_document.nodes_mut().push(panes);
         kdl_document.nodes_mut().push(connected_clients);
         kdl_document.nodes_mut().push(available_layouts);
+        kdl_document.nodes_mut().push(tab_history);
         kdl_document.fmt();
         kdl_document.to_string()
     }
@@ -5067,6 +5110,7 @@ fn serialize_and_deserialize_session_info_with_data() {
             LayoutInfo::File("layout3".to_owned()),
         ],
         plugins: Default::default(),
+        tab_history: Default::default(),
     };
     let serialized = session_info.to_string();
     let deserealized = SessionInfo::from_string(&serialized, "not this session").unwrap();
diff --git a/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info.snap b/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info.snap
index 32925ec1..aaaa6ba7 100644
--- a/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info.snap
+++ b/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info.snap
@@ -1,6 +1,6 @@
 ---
 source: zellij-utils/src/kdl/mod.rs
-assertion_line: 2459
+assertion_line: 5000
 expression: serialized
 ---
 name ""
@@ -11,4 +11,6 @@ panes {
 connected_clients 0
 available_layouts {
 }
+tab_history {
+}
 
diff --git a/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info_with_data.snap b/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info_with_data.snap
index 6e0ba4c5..a0401386 100644
--- a/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info_with_data.snap
+++ b/zellij-utils/src/kdl/snapshots/zellij_utils__kdl__serialize_and_deserialize_session_info_with_data.snap
@@ -1,6 +1,6 @@
 ---
 source: zellij-utils/src/kdl/mod.rs
-assertion_line: 5070
+assertion_line: 5111
 expression: serialized
 ---
 name "my session name"
@@ -95,4 +95,6 @@ available_layouts {
     layout2 source="built-in"
     layout3 source="file"
 }
+tab_history {
+}
 
diff --git a/zellij-utils/src/plugin_api/event.proto b/zellij-utils/src/plugin_api/event.proto
index 7269cc47..14eb0c40 100644
--- a/zellij-utils/src/plugin_api/event.proto
+++ b/zellij-utils/src/plugin_api/event.proto
@@ -257,6 +257,12 @@ message SessionManifest {
   bool is_current_session = 5;
   repeated LayoutInfo available_layouts = 6;
   repeated PluginInfo plugins = 7;
+  repeated ClientTabHistory tab_history = 8;
+}
+
+message ClientTabHistory {
+  uint32 client_id = 1;
+  repeated uint32 tab_history = 2;
 }
 
 message PluginInfo {
diff --git a/zellij-utils/src/plugin_api/event.rs b/zellij-utils/src/plugin_api/event.rs
index 743e1569..4707d657 100644
--- a/zellij-utils/src/plugin_api/event.rs
+++ b/zellij-utils/src/plugin_api/event.rs
@@ -2,14 +2,14 @@ pub use super::generated_api::api::{
     action::{Action as ProtobufAction, Position as ProtobufPosition},
     event::{
         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,
+        ClientTabHistory as ProtobufClientTabHistory, 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,
@@ -771,10 +771,23 @@ impl TryFrom<SessionInfo> for ProtobufSessionManifest {
                 .into_iter()
                 .map(|p| ProtobufPluginInfo::from(p))
                 .collect(),
+            tab_history: session_info
+                .tab_history
+                .into_iter()
+                .map(|t| ProtobufClientTabHistory::from(t))
+                .collect(),
         })
     }
 }
 
+impl From<(u16, Vec<usize>)> for ProtobufClientTabHistory {
+    fn from((client_id, tab_history): (u16, Vec<usize>)) -> ProtobufClientTabHistory {
+        ProtobufClientTabHistory {
+            client_id: client_id as u32,
+            tab_history: tab_history.into_iter().map(|t| t as u32).collect(),
+        }
+    }
+}
 impl From<(u32, PluginInfo)> for ProtobufPluginInfo {
     fn from((plugin_id, plugin_info): (u32, PluginInfo)) -> ProtobufPluginInfo {
         ProtobufPluginInfo {
@@ -821,6 +834,16 @@ impl TryFrom<ProtobufSessionManifest> for SessionInfo {
                 },
             );
         }
+        let mut tab_history = BTreeMap::new();
+        for client_tab_history in protobuf_session_manifest.tab_history.into_iter() {
+            let client_id = client_tab_history.client_id;
+            let tab_history_for_client = client_tab_history
+                .tab_history
+                .iter()
+                .map(|t| *t as usize)
+                .collect();
+            tab_history.insert(client_id as u16, tab_history_for_client);
+        }
         Ok(SessionInfo {
             name: protobuf_session_manifest.name,
             tabs: protobuf_session_manifest
@@ -837,6 +860,7 @@ impl TryFrom<ProtobufSessionManifest> for SessionInfo {
                 .filter_map(|l| LayoutInfo::try_from(l).ok())
                 .collect(),
             plugins,
+            tab_history,
         })
     }
 }
@@ -1921,6 +1945,9 @@ fn serialize_session_update_event_with_non_default_values() {
             configuration: plugin_configuration,
         },
     );
+    let mut tab_history = BTreeMap::new();
+    tab_history.insert(1, vec![1, 2, 3]);
+    tab_history.insert(2, vec![1, 2, 3]);
     let session_info_1 = SessionInfo {
         name: "session 1".to_owned(),
         tabs: tab_infos,
@@ -1933,6 +1960,7 @@ fn serialize_session_update_event_with_non_default_values() {
             LayoutInfo::File("layout3".to_owned()),
         ],
         plugins,
+        tab_history,
     };
     let session_info_2 = SessionInfo {
         name: "session 2".to_owned(),
@@ -1948,6 +1976,7 @@ fn serialize_session_update_event_with_non_default_values() {
             LayoutInfo::File("layout3".to_owned()),
         ],
         plugins: Default::default(),
+        tab_history: Default::default(),
     };
     let session_infos = vec![session_info_1, session_info_2];
     let resurrectable_sessions = vec![];