Improve CLI interface (add detach, switch session, blocking zellij run and more) (#4492)

* initial implementation

* fix tests

* move more ations

* screen adjustments (does not compile)

* plugin/pty adjustments (does not compile)

* more progress, tests not compiling

* fix tests

* more progress, does not compile

* more progress, compiles, tests failing

* tests passing

* rely on Drop for NotificationEnd

* atomicify some more actions

* fmt

* move unblock input to route

* don't pass hard-coded action names

* refactor: consolidate completion channel logic

* comment

* track last active client

* track cli clients explicitly

* use the last active client for cli commands when possible

* fix focus-next-pane for multiple clients

* various fixes for multi-client actions from the cli

* add detach action

* fix tests

* add switch session cli action

* fix switch session deadlock

* add and layout to switch-session cli action

* blocking zellij run: add NewBlockingPane variant

* blocking zellij run: wait forever mechanism

* blocking zellij run: thread NotificationEnd as needed  until TerminalPane (tests not compiling)

* blocking zellij run: update cli

* blocking zellij run: add command

* blocking zellij run: finish implementation

* fix tests

* e2e test and close_on_exit fixes

* fmt

* fix e2e tests

* fix plugin tests

5 files changed, 146 insertions, 2 deletions

diff --git a/src/main.rs b/src/main.rs
index 2b2e213a..f077c199 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -39,6 +39,7 @@ fn main() {
             height,
             pinned,
             stacked,
+            blocking,
         })) = opts.command
         {
             let cwd = cwd.or_else(|| std::env::current_dir().ok());
@@ -61,6 +62,7 @@ fn main() {
                 height,
                 pinned,
                 stacked,
+                blocking,
             };
             commands::send_action_to_session(command_cli_action, opts.session, config);
             std::process::exit(0);
@@ -80,6 +82,7 @@ fn main() {
         {
             let cwd = None;
             let stacked = false;
+            let blocking = false;
             let command_cli_action = CliAction::NewPane {
                 command: vec![],
                 plugin: Some(url),
@@ -98,6 +101,7 @@ fn main() {
                 height,
                 pinned,
                 stacked,
+                blocking,
             };
             commands::send_action_to_session(command_cli_action, opts.session, config);
             std::process::exit(0);
diff --git a/src/tests/e2e/cases.rs b/src/tests/e2e/cases.rs
index d2096cea..eab81039 100644
--- a/src/tests/e2e/cases.rs
+++ b/src/tests/e2e/cases.rs
@@ -2317,6 +2317,8 @@ pub fn send_command_through_the_cli() {
                             fixture_folder
                         ));
                         std::thread::sleep(std::time::Duration::from_millis(100));
+                        remote_terminal.send_key(&ENTER);
+                        std::thread::sleep(std::time::Duration::from_millis(100));
                         step_is_complete = true;
                     }
                     step_is_complete
@@ -2396,6 +2398,102 @@ pub fn send_command_through_the_cli() {
 
 #[test]
 #[ignore]
+pub fn send_blocking_command_through_the_cli() {
+    // here we test the following flow:
+    // - send a blocking command through the cli with --blocking --floating --close-on-exit
+    // - the command sleeps for 2 seconds (longer than the default 1s timeout) then exits with status 42
+    // - verify that the CLI blocks for the full duration (we check after 2+ seconds)
+    // - verify that the floating pane appears while running and disappears after completion
+    // - verify that the exit status is properly propagated
+    let fake_win_size = Size {
+        cols: 150,
+        rows: 24,
+    };
+    let mut test_attempts = 10;
+    let last_snapshot = loop {
+        RemoteRunner::kill_running_sessions(fake_win_size);
+        let mut runner = RemoteRunner::new(fake_win_size)
+            .add_step(Step {
+                name: "Run blocking command through the cli",
+                instruction: |mut remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    if remote_terminal.status_bar_appears()
+                        && remote_terminal.cursor_position_is(3, 2)
+                    {
+                        // Send a command that sleeps for 2 seconds then exits with status 42
+                        // Using bash -c with proper escaping
+                        // remote_terminal.send_key("aaa\n".as_bytes());
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        remote_terminal.send_blocking_command_through_the_cli(
+                            // "lskdjlskdjf"
+                            "bash -c 'sleep 2 && exit 42'",
+                        );
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        remote_terminal.send_key(&ENTER);
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        step_is_complete = true;
+                    }
+                    step_is_complete
+                },
+            })
+            .add_step(Step {
+                name: "Wait for floating pane to appear",
+                instruction: |remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    // The floating pane should appear with the running command
+                    if remote_terminal.snapshot_contains("PIN [ ]") {
+                        std::thread::sleep(std::time::Duration::from_millis(2000)); // wait for
+                                                                                    // command to
+                                                                                    // end
+                        step_is_complete = true
+                    }
+                    step_is_complete
+                },
+            })
+            .add_step(Step {
+                name: "Wait for command to complete and verify exit status",
+                instruction: |mut remote_terminal: RemoteTerminal| -> bool {
+                    let mut step_is_complete = false;
+                    // After 2+ seconds, the command should complete and the floating pane should close
+                    // then we do echo $? to make sure we got back its exit status
+                    if !remote_terminal.snapshot_contains("PIN [ ]") {
+                        remote_terminal.send_key("echo $?".as_bytes());
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        remote_terminal.send_key(&ENTER);
+                        std::thread::sleep(std::time::Duration::from_millis(100));
+                        step_is_complete = true
+                    }
+                    step_is_complete
+                },
+            });
+        runner.run_all_steps();
+
+        let last_snapshot = runner.take_snapshot_after(Step {
+            name: "Verify CLI returned with proper exit status after command completed",
+            instruction: |remote_terminal: RemoteTerminal| -> bool {
+                let mut step_is_complete = false;
+                if remote_terminal.snapshot_contains("echo $?")
+                    && remote_terminal.status_bar_appears()
+                {
+                    step_is_complete = true
+                }
+                step_is_complete
+            },
+        });
+
+        if runner.test_timed_out && test_attempts > 0 {
+            test_attempts -= 1;
+            continue;
+        } else {
+            break last_snapshot;
+        }
+    };
+    let last_snapshot = account_for_races_in_snapshot(last_snapshot);
+    assert_snapshot!(last_snapshot);
+}
+
+#[test]
+#[ignore]
 pub fn load_plugins_in_background_on_startup() {
     let fake_win_size = Size {
         cols: 120,
diff --git a/src/tests/e2e/remote_runner.rs b/src/tests/e2e/remote_runner.rs
index a9b345b7..377869f9 100644
--- a/src/tests/e2e/remote_runner.rs
+++ b/src/tests/e2e/remote_runner.rs
@@ -273,6 +273,7 @@ fn read_from_channel(
                     arrow_fonts,
                     styled_underlines,
                     explicitly_disable_kitty_keyboard_protocol,
+                    None,
                 ); // 0 is the pane index
                 loop {
                     if !should_keep_running.load(Ordering::SeqCst) {
@@ -423,7 +424,20 @@ impl RemoteTerminal {
         channel
             .write_all(
                 // note that this is run with the -s flag that suspends the command on startup
-                format!("{} run -s -- \"{}\"\n", ZELLIJ_EXECUTABLE_LOCATION, command).as_bytes(),
+                format!("{} run -s -- \"{}\"", ZELLIJ_EXECUTABLE_LOCATION, command).as_bytes(),
+            )
+            .unwrap();
+        channel.flush().unwrap();
+    }
+    pub fn send_blocking_command_through_the_cli(&mut self, command: &str) {
+        let mut channel = self.channel.lock().unwrap();
+        channel
+            .write_all(
+                format!(
+                    "{} run --blocking --floating --close-on-exit -- {}",
+                    ZELLIJ_EXECUTABLE_LOCATION, command
+                )
+                .as_bytes(),
             )
             .unwrap();
         channel.flush().unwrap();
diff --git a/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_blocking_command_through_the_cli.snap b/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_blocking_command_through_the_cli.snap
new file mode 100644
index 00000000..0dce3a50
--- /dev/null
+++ b/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_blocking_command_through_the_cli.snap
@@ -0,0 +1,28 @@
+---
+source: src/tests/e2e/cases.rs
+expression: last_snapshot
+---
+ Zellij (e2e-test)  Tab #1 
+┌ Pane #1 ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
+│$ /usr/src/zellij/x86_64-unknown-linux-musl/release/zellij run --blocking --floating --close-on-exit -- bash -c 'sleep 2 && exit 42'                │
+│$                                                                                                                                                   │
+│$ echo $?                                                                                                                                           │
+│42                                                                                                                                                  │
+│$                                                                                                                                                   │
+│$ █                                                                                                                                                 │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+│                                                                                                                                                    │
+└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
+ Ctrl + <g> LOCK  <p> PANE  <t> TAB  <n> RESIZE  <h> MOVE  <s> SEARCH  <o> SESSION  <q> QUIT  Alt +  <n> New Pane  <f> Floating 
diff --git a/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_command_through_the_cli.snap b/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_command_through_the_cli.snap
index 1e1a014b..228407bd 100644
--- a/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_command_through_the_cli.snap
+++ b/src/tests/e2e/snapshots/zellij__tests__e2e__cases__send_command_through_the_cli.snap
@@ -7,7 +7,7 @@ expression: last_snapshot
 │$ /usr/src/zellij/x86_64-unknown-linux-musl/release/zellij run -s -- "/us││foo                                                                      │
 │r/src/zellij/fixtures/append-echo-script.sh"                             ││foo                                                                      │
 │$                                                                        ││█                                                                        │
-│                                                                         ││                                                                         │
+│$                                                                        ││                                                                         │
 │                                                                         ││                                                                         │
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