Move screen and plugins to client side.

Remove AppInstruction enum
spawn pty thread, screen thread and plugin thread on demand

12 files changed, 918 insertions, 1021 deletions

diff --git a/src/client/mod.rs b/src/client/mod.rs
index e91ad07e3..ae298a5eb 100644
--- a/src/client/mod.rs
+++ b/src/client/mod.rs
@@ -4,66 +4,32 @@ pub mod pane_resizer;
 pub mod panes;
 pub mod tab;
 
+use serde::{Deserialize, Serialize};
+use std::io::Write;
 use std::sync::mpsc;
 use std::thread;
-use std::{collections::HashMap, fs};
-use std::{
-    collections::HashSet,
-    io::Write,
-    str::FromStr,
-    sync::{Arc, Mutex},
-};
-
-use directories_next::ProjectDirs;
-use serde::{Deserialize, Serialize};
-use wasmer::{ChainableNamedResolver, Instance, Module, Store, Value};
-use wasmer_wasi::{Pipe, WasiState};
-use zellij_tile::data::{EventType, InputMode};
 
-use crate::cli::CliArgs;
 use crate::common::{
     command_is_executing::CommandIsExecuting,
-    errors::{AppContext, ContextType, PluginContext, ScreenContext},
+    errors::{ClientContext, ContextType},
     input::handler::input_loop,
     os_input_output::ClientOsApi,
-    pty_bus::PtyInstruction,
-    screen::{Screen, ScreenInstruction},
-    wasm_vm::{wasi_stdout, wasi_write_string, zellij_imports, PluginEnv, PluginInstruction},
-    ChannelWithContext, SenderType, SenderWithContext, SyncChannelWithContext, OPENCALLS,
+    SenderType, SenderWithContext, SyncChannelWithContext, OPENCALLS,
 };
-use crate::layout::Layout;
 use crate::server::ServerInstruction;
 
-/// Instructions sent from server to client
+/// Instructions related to the client-side application and sent from server to client
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub enum ClientInstruction {
-    ToScreen(ScreenInstruction),
-    ClosePluginPane(u32),
     Error(String),
+    Render(String),
     DoneClosingPane,
+    DoneOpeningNewPane,
+    DoneUpdatingTabs,
     Exit,
 }
 
-/// Instructions related to the client-side application.
-#[derive(Clone)]
-pub enum AppInstruction {
-    Exit,
-    Error(String),
-    ToPty(PtyInstruction),
-    DoneClosingPane,
-}
-
-impl From<ClientInstruction> for AppInstruction {
-    fn from(item: ClientInstruction) -> Self {
-        match item {
-            ClientInstruction::Error(e) => AppInstruction::Error(e),
-            ClientInstruction::DoneClosingPane => AppInstruction::DoneClosingPane,
-            _ => panic!("Unsupported AppInstruction"),
-        }
-    }
-}
-
-pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs) {
+pub fn start_client(mut os_input: Box<dyn ClientOsApi>) {
     let take_snapshot = "\u{1b}[?1049h";
     os_input.unset_raw_mode(0);
     let _ = os_input
@@ -75,378 +41,68 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs) {
 
     let full_screen_ws = os_input.get_terminal_size_using_fd(0);
     os_input.set_raw_mode(0);
-    let (send_screen_instructions, receive_screen_instructions): ChannelWithContext<
-        ScreenInstruction,
-    > = mpsc::channel();
     let err_ctx = OPENCALLS.with(|ctx| *ctx.borrow());
-    let mut send_screen_instructions =
-        SenderWithContext::new(err_ctx, SenderType::Sender(send_screen_instructions));
-
-    let (send_plugin_instructions, receive_plugin_instructions): ChannelWithContext<
-        PluginInstruction,
-    > = mpsc::channel();
-    let send_plugin_instructions =
-        SenderWithContext::new(err_ctx, SenderType::Sender(send_plugin_instructions));
 
-    let (send_app_instructions, receive_app_instructions): SyncChannelWithContext<AppInstruction> =
-        mpsc::sync_channel(500);
-    let mut send_app_instructions =
-        SenderWithContext::new(err_ctx, SenderType::SyncSender(send_app_instructions));
+    let (send_client_instructions, receive_client_instructions): SyncChannelWithContext<
+        ClientInstruction,
+    > = mpsc::sync_channel(500);
+    let mut send_client_instructions =
+        SenderWithContext::new(err_ctx, SenderType::SyncSender(send_client_instructions));
 
-    os_input.connect_to_server();
+    os_input.connect_to_server(full_screen_ws);
 
     #[cfg(not(test))]
     std::panic::set_hook({
         use crate::errors::handle_panic;
-        let send_app_instructions = send_app_instructions.clone();
+        let send_client_instructions = send_client_instructions.clone();
         Box::new(move |info| {
-            handle_panic(info, &send_app_instructions);
+            handle_panic(info, &send_client_instructions);
         })
     });
 
-    let screen_thread = thread::Builder::new()
-        .name("screen".to_string())
-        .spawn({
-            let mut command_is_executing = command_is_executing.clone();
-            let os_input = os_input.clone();
-            let send_plugin_instructions = send_plugin_instructions.clone();
-            let send_app_instructions = send_app_instructions.clone();
-            let max_panes = opts.max_panes;
-
-            move || {
-                let mut screen = Screen::new(
-                    receive_screen_instructions,
-                    send_plugin_instructions,
-                    send_app_instructions,
-                    &full_screen_ws,
-                    os_input,
-                    max_panes,
-                    InputMode::Normal,
-                );
-                loop {
-                    let (event, mut err_ctx) = screen
-                        .receiver
-                        .recv()
-                        .expect("failed to receive event on channel");
-                    err_ctx.add_call(ContextType::Screen(ScreenContext::from(&event)));
-                    screen.send_app_instructions.update(err_ctx);
-                    screen.os_api.update_senders(err_ctx);
-                    if let Some(t) = screen.get_active_tab_mut() {
-                        t.os_api.update_senders(err_ctx);
-                    }
-                    match event {
-                        ScreenInstruction::Pty(pid, vte_event) => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .handle_pty_event(pid, vte_event);
-                        }
-                        ScreenInstruction::Render => {
-                            screen.render();
-                        }
-                        ScreenInstruction::NewPane(pid) => {
-                            screen.get_active_tab_mut().unwrap().new_pane(pid);
-                            command_is_executing.done_opening_new_pane();
-                        }
-                        ScreenInstruction::HorizontalSplit(pid) => {
-                            screen.get_active_tab_mut().unwrap().horizontal_split(pid);
-                            command_is_executing.done_opening_new_pane();
-                        }
-                        ScreenInstruction::VerticalSplit(pid) => {
-                            screen.get_active_tab_mut().unwrap().vertical_split(pid);
-                            command_is_executing.done_opening_new_pane();
-                        }
-                        ScreenInstruction::WriteCharacter(bytes) => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .write_to_active_terminal(bytes);
-                        }
-                        ScreenInstruction::ResizeLeft => {
-                            screen.get_active_tab_mut().unwrap().resize_left();
-                        }
-                        ScreenInstruction::ResizeRight => {
-                            screen.get_active_tab_mut().unwrap().resize_right();
-                        }
-                        ScreenInstruction::ResizeDown => {
-                            screen.get_active_tab_mut().unwrap().resize_down();
-                        }
-                        ScreenInstruction::ResizeUp => {
-                            screen.get_active_tab_mut().unwrap().resize_up();
-                        }
-                        ScreenInstruction::MoveFocus => {
-                            screen.get_active_tab_mut().unwrap().move_focus();
-                        }
-                        ScreenInstruction::MoveFocusLeft => {
-                            screen.get_active_tab_mut().unwrap().move_focus_left();
-                        }
-                        ScreenInstruction::MoveFocusDown => {
-                            screen.get_active_tab_mut().unwrap().move_focus_down();
-                        }
-                        ScreenInstruction::MoveFocusRight => {
-                            screen.get_active_tab_mut().unwrap().move_focus_right();
-                        }
-                        ScreenInstruction::MoveFocusUp => {
-                            screen.get_active_tab_mut().unwrap().move_focus_up();
-                        }
-                        ScreenInstruction::ScrollUp => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .scroll_active_terminal_up();
-                        }
-                        ScreenInstruction::ScrollDown => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .scroll_active_terminal_down();
-                        }
-                        ScreenInstruction::ClearScroll => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .clear_active_terminal_scroll();
-                        }
-                        ScreenInstruction::CloseFocusedPane => {
-                            screen.get_active_tab_mut().unwrap().close_focused_pane();
-                            screen.render();
-                        }
-                        ScreenInstruction::SetSelectable(id, selectable) => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .set_pane_selectable(id, selectable);
-                        }
-                        ScreenInstruction::SetMaxHeight(id, max_height) => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .set_pane_max_height(id, max_height);
-                        }
-                        ScreenInstruction::SetInvisibleBorders(id, invisible_borders) => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .set_pane_invisible_borders(id, invisible_borders);
-                            screen.render();
-                        }
-                        ScreenInstruction::ClosePane(id) => {
-                            screen.get_active_tab_mut().unwrap().close_pane(id);
-                            screen.render();
-                        }
-                        ScreenInstruction::ToggleActiveTerminalFullscreen => {
-                            screen
-                                .get_active_tab_mut()
-                                .unwrap()
-                                .toggle_active_pane_fullscreen();
-                        }
-                        ScreenInstruction::NewTab(pane_id) => {
-                            screen.new_tab(pane_id);
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::SwitchTabNext => {
-                            screen.switch_tab_next();
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::SwitchTabPrev => {
-                            screen.switch_tab_prev();
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::CloseTab => {
-                            screen.close_tab();
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::ApplyLayout((layout, new_pane_pids)) => {
-                            screen.apply_layout(Layout::new(layout), new_pane_pids);
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::GoToTab(tab_index) => {
-                            screen.go_to_tab(tab_index as usize);
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::UpdateTabName(c) => {
-                            screen.update_active_tab_name(c);
-                            command_is_executing.done_updating_tabs();
-                        }
-                        ScreenInstruction::ChangeInputMode(input_mode) => {
-                            screen.change_input_mode(input_mode);
-                        }
-                        ScreenInstruction::Exit => {
-                            break;
-                        }
-                    }
-                }
-            }
-        })
-        .unwrap();
-
-    let wasm_thread = thread::Builder::new()
-        .name("wasm".to_string())
-        .spawn({
-            let mut send_screen_instructions = send_screen_instructions.clone();
-            let mut send_app_instructions = send_app_instructions.clone();
-
-            let store = Store::default();
-            let mut plugin_id = 0;
-            let mut plugin_map = HashMap::new();
-            move || loop {
-                let (event, mut err_ctx) = receive_plugin_instructions
-                    .recv()
-                    .expect("failed to receive event on channel");
-                err_ctx.add_call(ContextType::Plugin(PluginContext::from(&event)));
-                send_screen_instructions.update(err_ctx);
-                send_app_instructions.update(err_ctx);
-                match event {
-                    PluginInstruction::Load(pid_tx, path) => {
-                        let project_dirs =
-                            ProjectDirs::from("org", "Zellij Contributors", "Zellij").unwrap();
-                        let plugin_dir = project_dirs.data_dir().join("plugins/");
-                        let wasm_bytes = fs::read(&path)
-                            .or_else(|_| fs::read(&path.with_extension("wasm")))
-                            .or_else(|_| fs::read(&plugin_dir.join(&path).with_extension("wasm")))
-                            .unwrap_or_else(|_| panic!("cannot find plugin {}", &path.display()));
-
-                        // FIXME: Cache this compiled module on disk. I could use `(de)serialize_to_file()` for that
-                        let module = Module::new(&store, &wasm_bytes).unwrap();
-
-                        let output = Pipe::new();
-                        let input = Pipe::new();
-                        let mut wasi_env = WasiState::new("Zellij")
-                            .env("CLICOLOR_FORCE", "1")
-                            .preopen(|p| {
-                                p.directory(".") // FIXME: Change this to a more meaningful dir
-                                    .alias(".")
-                                    .read(true)
-                                    .write(true)
-                                    .create(true)
-                            })
-                            .unwrap()
-                            .stdin(Box::new(input))
-                            .stdout(Box::new(output))
-                            .finalize()
-                            .unwrap();
-
-                        let wasi = wasi_env.import_object(&module).unwrap();
-
-                        let plugin_env = PluginEnv {
-                            plugin_id,
-                            send_screen_instructions: send_screen_instructions.clone(),
-                            send_app_instructions: send_app_instructions.clone(),
-                            wasi_env,
-                            subscriptions: Arc::new(Mutex::new(HashSet::new())),
-                        };
-
-                        let zellij = zellij_imports(&store, &plugin_env);
-                        let instance = Instance::new(&module, &zellij.chain_back(wasi)).unwrap();
-
-                        let start = instance.exports.get_function("_start").unwrap();
-
-                        // This eventually calls the `.init()` method
-                        start.call(&[]).unwrap();
-
-                        plugin_map.insert(plugin_id, (instance, plugin_env));
-                        pid_tx.send(plugin_id).unwrap();
-                        plugin_id += 1;
-                    }
-                    PluginInstruction::Update(pid, event) => {
-                        for (&i, (instance, plugin_env)) in &plugin_map {
-                            let subs = plugin_env.subscriptions.lock().unwrap();
-                            // FIXME: This is very janky... Maybe I should write my own macro for Event -> EventType?
-                            let event_type = EventType::from_str(&event.to_string()).unwrap();
-                            if (pid.is_none() || pid == Some(i)) && subs.contains(&event_type) {
-                                let update = instance.exports.get_function("update").unwrap();
-                                wasi_write_string(
-                                    &plugin_env.wasi_env,
-                                    &serde_json::to_string(&event).unwrap(),
-                                );
-                                update.call(&[]).unwrap();
-                            }
-                        }
-                        drop(send_screen_instructions.send(ScreenInstruction::Render));
-                    }
-                    PluginInstruction::Render(buf_tx, pid, rows, cols) => {
-                        let (instance, plugin_env) = plugin_map.get(&pid).unwrap();
-
-                        let render = instance.exports.get_function("render").unwrap();
-
-                        render
-                            .call(&[Value::I32(rows as i32), Value::I32(cols as i32)])
-                            .unwrap();
-
-                        buf_tx.send(wasi_stdout(&plugin_env.wasi_env)).unwrap();
-                    }
-                    PluginInstruction::Unload(pid) => drop(plugin_map.remove(&pid)),
-                    PluginInstruction::Exit => break,
-                }
-            }
-        })
-        .unwrap();
-
     let _stdin_thread = thread::Builder::new()
         .name("stdin_handler".to_string())
         .spawn({
-            let send_screen_instructions = send_screen_instructions.clone();
-            let send_plugin_instructions = send_plugin_instructions.clone();
-            let send_app_instructions = send_app_instructions.clone();
+            let send_client_instructions = send_client_instructions.clone();
             let command_is_executing = command_is_executing.clone();
             let os_input = os_input.clone();
-            move || {
-                input_loop(
-                    os_input,
-                    command_is_executing,
-                    send_screen_instructions,
-                    send_plugin_instructions,
-                    send_app_instructions,
-                )
-            }
+            move || input_loop(os_input, command_is_executing, send_client_instructions)
         });
 
     let router_thread = thread::Builder::new()
         .name("router".to_string())
         .spawn({
-            let mut send_screen_instructions = send_screen_instructions.clone();
-            let mut send_plugin_instructions = send_plugin_instructions.clone();
             let os_input = os_input.clone();
-            move || loop {
-                let (instruction, err_ctx) = os_input.client_recv();
-                send_app_instructions.update(err_ctx);
-                send_screen_instructions.update(err_ctx);
-                send_plugin_instructions.update(err_ctx);
-                match instruction {
-                    ClientInstruction::Exit => break,
-                    ClientInstruction::ClosePluginPane(p) => {
-                        send_plugin_instructions
-                            .send(PluginInstruction::Unload(p))
-                            .unwrap();
-                    }
-                    ClientInstruction::ToScreen(s) => send_screen_instructions.send(s).unwrap(),
-                    _ => {
-                        send_app_instructions
-                            .send(AppInstruction::from(instruction))
-                            .unwrap();
+            move || {
+                loop {
+                    let (instruction, err_ctx) = os_input.client_recv();
+                    send_client_instructions.update(err_ctx);
+                    if let ClientInstruction::Exit = instruction {
+                        break;
                     }
+                    send_client_instructions.send(instruction).unwrap();
                 }
+                send_client_instructions
+                    .send(ClientInstruction::Exit)
+                    .unwrap();
             }
         })
         .unwrap();
 
     #[warn(clippy::never_loop)]
     loop {
-        let (app_instruction, mut err_ctx) = receive_app_instructions
+        let (client_instruction, mut err_ctx) = receive_client_instructions
             .recv()
             .expect("failed to receive app instruction on channel");
 
-        err_ctx.add_call(ContextType::App(AppContext::from(&app_instruction)));
-        send_screen_instructions.update(err_ctx);
+        err_ctx.add_call(ContextType::Client(ClientContext::from(
+            &client_instruction,
+        )));
         os_input.update_senders(err_ctx);
-        match app_instruction {
-            AppInstruction::Exit => break,
-            AppInstruction::Error(backtrace) => {
+        match client_instruction {
+            ClientInstruction::Exit => break,
+            ClientInstruction::Error(backtrace) => {
                 let _ = os_input.send_to_server(ServerInstruction::ClientExit);
-                let _ = send_screen_instructions.send(ScreenInstruction::Exit);
-                let _ = send_plugin_instructions.send(PluginInstruction::Exit);
-                let _ = screen_thread.join();
-                let _ = wasm_thread.join();
                 os_input.unset_raw_mode(0);
                 let goto_start_of_last_line = format!("\u{1b}[{};{}H", full_screen_ws.rows, 1);
                 let error = format!("{}\n{}", goto_start_of_last_line, backtrace);
@@ -456,18 +112,20 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs) {
                     .unwrap();
                 std::process::exit(1);
             }
-            AppInstruction::ToPty(instruction) => {
-                os_input.send_to_server(ServerInstruction::ToPty(instruction));
+            ClientInstruction::Render(output) => {
+                let mut stdout = os_input.get_stdout_writer();
+                stdout
+                    .write_all(&output.as_bytes())
+                    .expect("cannot write to stdout");
+                stdout.flush().expect("could not flush");
             }
-            AppInstruction::DoneClosingPane => command_is_executing.done_closing_pane(),
+            ClientInstruction::DoneClosingPane => command_is_executing.done_closing_pane(),
+            ClientInstruction::DoneOpeningNewPane => command_is_executing.done_opening_new_pane(),
+            ClientInstruction::DoneUpdatingTabs => command_is_executing.done_updating_tabs(),
         }
     }
 
     let _ = os_input.send_to_server(ServerInstruction::ClientExit);
-    let _ = send_screen_instructions.send(ScreenInstruction::Exit);
-    let _ = send_plugin_instructions.send(PluginInstruction::Exit);
-    screen_thread.join().unwrap();
-    wasm_thread.join().unwrap();
     router_thread.join().unwrap();
 
     // cleanup();
@@ -481,9 +139,7 @@ pub fn start_client(mut os_input: Box<dyn ClientOsApi>, opts: CliArgs) {
     );
 
     os_input.unset_raw_mode(0);
-    let _ = os_input
-        .get_stdout_writer()
-        .write(goodbye_message.as_bytes())
-        .unwrap();
-    os_input.get_stdout_writer().flush().unwrap();
+    let mut stdout = os_input.get_stdout_writer();
+    let _ = stdout.write(goodbye_message.as_bytes()).unwrap();
+    stdout.flush().unwrap();
 }
diff --git a/src/client/panes/terminal_pane.rs b/src/client/panes/terminal_pane.rs
index 7eb3f17cb..91db15caa 100644
--- a/src/client/panes/terminal_pane.rs
+++ b/src/client/panes/terminal_pane.rs
@@ -20,7 +20,7 @@ pub enum PaneId {
 
 /// Contains the position and size of a [`Pane`], or more generally of any terminal, measured
 /// in character rows and columns.
-#[derive(Clone, Copy, Debug, Default)]
+#[derive(Clone, Copy, Debug, Default, Serialize, Deserialize)]
 pub struct PositionAndSize {
     pub x: usize,
     pub y: usize,
diff --git a/src/client/tab.rs b/src/client/tab.rs
index 1a0cee2a9..23ced34f9 100644
--- a/src/client/tab.rs
+++ b/src/client/tab.rs
@@ -2,10 +2,9 @@
 //! as well as how they should be resized
 
 use crate::boundaries::colors;
-use crate::client::AppInstruction;
 use crate::common::{input::handler::parse_keys, SenderWithContext};
 use crate::layout::Layout;
-use crate::os_input_output::{ClientOsApi, ServerOsApiInstruction};
+use crate::os_input_output::ServerOsApi;
 use crate::panes::{PaneId, PositionAndSize, TerminalPane};
 use crate::pty_bus::{PtyInstruction, VteEvent};
 use crate::server::ServerInstruction;
@@ -13,12 +12,12 @@ use crate::utils::shared::pad_to_size;
 use crate::wasm_vm::PluginInstruction;
 use crate::{boundaries::Boundaries, panes::PluginPane};
 use std::os::unix::io::RawFd;
+use std::sync::mpsc::channel;
 use std::{
     cmp::Reverse,
     collections::{BTreeMap, HashSet},
 };
-use std::{io::Write, sync::mpsc::channel};
-use zellij_tile::data::{Event, ModeInfo};
+use zellij_tile::data::{Event, InputMode};
 
 const CURSOR_HEIGHT_WIDTH_RATIO: usize = 4; // this is not accurate and kind of a magic number, TODO: look into this
 const MIN_TERMINAL_HEIGHT: usize = 2;
@@ -64,9 +63,10 @@ pub struct Tab {
     max_panes: Option<usize>,
     full_screen_ws: PositionAndSize,
     fullscreen_is_active: bool,
-    pub os_api: Box<dyn ClientOsApi>,
-    pub send_plugin_instructions: SenderWithContext<PluginInstruction>,
-    pub send_app_instructions: SenderWithContext<AppInstruction>,
+    os_api: Box<dyn ServerOsApi>,
+    send_plugin_instructions: SenderWithContext<PluginInstruction>,
+    send_pty_instructions: SenderWithContext<PtyInstruction>,
+    send_server_instructions: SenderWithContext<ServerInstruction>,
     expansion_boundary: Option<PositionA