feat(plugins): introduce 'pipes', allowing users to pipe data to and control plugins from the command line (#3066)

* prototype - working with message from the cli

* prototype - pipe from the CLI to plugins

* prototype - pipe from the CLI to plugins and back again

* prototype - working with better cli interface

* prototype - working after removing unused stuff

* prototype - working with launching plugin if it is not launched, also fixed event ordering

* refactor: change message to cli-message

* prototype - allow plugins to send messages to each other

* fix: allow cli messages to send plugin parameters (and implement backpressure)

* fix: use input_pipe_id to identify cli pipes instead of their message name

* fix: come cleanups and add skip_cache parameter

* fix: pipe/client-server communication robustness

* fix: leaking messages between plugins while loading

* feat: allow plugins to specify how a new plugin instance is launched when sending messages

* fix: add permissions

* refactor: adjust cli api

* fix: improve cli plugin loading error messages

* docs: cli pipe

* fix: take plugin configuration into account when messaging between plugins

* refactor: pipe message protobuf interface

* refactor: update(event) -> pipe

* refactor - rename CliMessage to CliPipe

* fix: add is_private to pipes and change some naming

* refactor - cli client

* refactor: various cleanups

* style(fmt): rustfmt

* fix(pipes): backpressure across multiple plugins

* style: some cleanups

* style(fmt): rustfmt

* style: fix merge conflict mistake

* style(wording): clarify pipe permission

1 files changed, 31 insertions, 0 deletions

diff --git a/default-plugins/fixture-plugin-for-tests/src/main.rs b/default-plugins/fixture-plugin-for-tests/src/main.rs
index 79783a1b..fcdc363f 100644
--- a/default-plugins/fixture-plugin-for-tests/src/main.rs
+++ b/default-plugins/fixture-plugin-for-tests/src/main.rs
@@ -11,6 +11,7 @@ struct State {
     received_events: Vec<Event>,
     received_payload: Option<String>,
     configuration: BTreeMap<String, String>,
+    message_to_plugin_payload: Option<String>,
 }
 
 #[derive(Default, Serialize, Deserialize)]
@@ -34,9 +35,12 @@ impl<'de> ZellijWorker<'de> for TestWorker {
     }
 }
 
+#[cfg(target_family = "wasm")]
 register_plugin!(State);
+#[cfg(target_family = "wasm")]
 register_worker!(TestWorker, test_worker, TEST_WORKER);
 
+#[cfg(target_family = "wasm")]
 impl ZellijPlugin for State {
     fn load(&mut self, configuration: BTreeMap<String, String>) {
         request_permission(&[
@@ -49,6 +53,8 @@ impl ZellijPlugin for State {
             PermissionType::OpenTerminalsOrPlugins,
             PermissionType::WriteToStdin,
             PermissionType::WebAccess,
+            PermissionType::ReadCliPipes,
+            PermissionType::MessageAndLaunchOtherPlugins,
         ]);
         self.configuration = configuration;
         subscribe(&[
@@ -295,10 +301,35 @@ impl ZellijPlugin for State {
         self.received_events.push(event);
         should_render
     }
+    fn pipe(&mut self, pipe_message: PipeMessage) -> bool {
+        let input_pipe_id = match pipe_message.source {
+            PipeSource::Cli(id) => id.clone(),
+            PipeSource::Plugin(id) => format!("{}", id),
+        };
+        let name = pipe_message.name;
+        let payload = pipe_message.payload;
+        if name == "message_name" && payload == Some("message_payload".to_owned()) {
+            unblock_cli_pipe_input(&input_pipe_id);
+        } else if name == "message_name_block" {
+            block_cli_pipe_input(&input_pipe_id);
+        } else if name == "pipe_output" {
+            cli_pipe_output(&name, "this_is_my_output");
+        } else if name == "pipe_message_to_plugin" {
+            pipe_message_to_plugin(
+                MessageToPlugin::new("message_to_plugin").with_payload("my_cool_payload"),
+            );
+        } else if name == "message_to_plugin" {
+            self.message_to_plugin_payload = payload.clone();
+        }
+        let should_render = true;
+        should_render
+    }
 
     fn render(&mut self, rows: usize, cols: usize) {
         if let Some(payload) = self.received_payload.as_ref() {
             println!("Payload from worker: {:?}", payload);
+        } else if let Some(payload) = self.message_to_plugin_payload.take() {
+            println!("Payload from self: {:?}", payload);
         } else {
             println!(
                 "Rows: {:?}, Cols: {:?}, Received events: {:?}",