From 6da63b6bed47c9e040da2cbe7f6468c8ff6360cb Mon Sep 17 00:00:00 2001
From: Austen Adler <agadler@austenadler.com>
Date: Sat, 17 Dec 2022 12:02:15 -0500
Subject: [PATCH] Use crossbeam for message passing

---
 src/command.rs | 19 +++++++++++++++++++
 src/event.rs   | 22 ++++++++++++++++++++++
 src/main.rs    | 31 +++++++++++++++++++++++++------
 src/worker.rs  |  3 +++
 4 files changed, 69 insertions(+), 6 deletions(-)
 create mode 100644 src/event.rs
 create mode 100644 src/worker.rs

diff --git a/src/command.rs b/src/command.rs
index e0af510..ae60560 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -1,6 +1,9 @@
+use crate::event::EventMessage;
 use anyhow::bail;
 use anyhow::Context;
 use anyhow::Result;
+use crossbeam::channel::Receiver;
+use crossbeam::channel::Sender;
 use std::{
     io::Write,
     process::{Command, Stdio},
@@ -8,6 +11,10 @@ use std::{
 
 use crate::App;
 
+pub struct CommandRequest {
+    cmdline: String,
+}
+
 pub struct CommandResult {
     pub status_success: bool,
     pub stdout: Vec<u8>,
@@ -24,6 +31,18 @@ impl Default for CommandResult {
     }
 }
 
+// pub fn command_event_loop(command_request_receiver: Receiver<CommandRequest>,event_sender: Sender<EventMessage>) -> Result<()> {
+//     loop {
+//         match command_request_receiver.recv() {
+//             Ok(command_request) => event_sender.send(EventMessage::CrosstermEvent(e))?,
+//             Err(e) => {
+//                 event_sender.send(EventMessage::CrosstermError(e))?;
+//                 bail!("Crossterm read error");
+//             }
+//         }
+//     }
+// }
+
 pub fn run(app: &mut App) {
     match run_inner(app) {
         Ok(c) => {
diff --git a/src/event.rs b/src/event.rs
new file mode 100644
index 0000000..51a50ae
--- /dev/null
+++ b/src/event.rs
@@ -0,0 +1,22 @@
+use crate::command::CommandRequest;
+use anyhow::bail;
+use anyhow::Result;
+use crossbeam::channel::Sender;
+
+pub enum EventMessage {
+    CommandCompleted,
+    CrosstermEvent(crossterm::event::Event),
+    CrosstermError(std::io::Error),
+}
+
+pub fn crossterm_event_loop(event_sender: Sender<EventMessage>) -> Result<()> {
+    loop {
+        match crossterm::event::read() {
+            Ok(e) => event_sender.send(EventMessage::CrosstermEvent(e))?,
+            Err(e) => {
+                event_sender.send(EventMessage::CrosstermError(e))?;
+                bail!("Crossterm read error");
+            }
+        }
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 43f9aa5..21b401e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@
 #![allow(clippy::module_name_repetitions, clippy::cast_possible_truncation)]
 
 mod command;
+mod event;
 mod ui;
 use ansi4tui::bytes_to_text;
 use anyhow::anyhow;
@@ -11,6 +12,7 @@ use anyhow::Result;
 use command::CommandResult;
 use crossterm::event::DisableBracketedPaste;
 use crossterm::event::EnableBracketedPaste;
+use event::EventMessage;
 use std::str::FromStr;
 use std::{
     io::{self, Write},
@@ -28,7 +30,7 @@ use tui::{
 };
 
 use crossterm::{
-    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
+    event::{DisableMouseCapture, EnableMouseCapture, Event, KeyCode},
     execute,
     terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
 };
@@ -230,7 +232,7 @@ fn main() -> Result<()> {
 fn run_app<B: Backend>(
     terminal: &mut Terminal<B>,
     mut app: App,
-) -> io::Result<Option<(String, Vec<u8>)>> {
+) -> Result<Option<(String, Vec<u8>)>> {
     if !app.cmdline.is_empty() {
         command::run(&mut app);
     }
@@ -239,11 +241,22 @@ fn run_app<B: Backend>(
         app.cmdline_position = app.cmdline.len() as u16;
     }
 
+    let (tx, rx) = crossbeam::channel::bounded(100);
+
+    // Start the event thread
+    let crossterm_tx = tx.clone();
+    std::thread::spawn(move || {
+        let _result = event::crossterm_event_loop(crossterm_tx);
+    });
+
+    std::mem::drop(tx);
+
     loop {
         terminal.draw(|f| ui::draw(f, &app))?;
 
-        match event::read()? {
-            Event::Key(key) => match key.code {
+        match rx.recv()? {
+            // match event::read()? {
+            EventMessage::CrosstermEvent(Event::Key(key)) => match key.code {
                 KeyCode::Esc => {
                     // TODO: If there is any command line text, ask if the user is sure they want to quit
                     return Ok(None);
@@ -297,7 +310,7 @@ fn run_app<B: Backend>(
                 }
                 _ => {}
             },
-            Event::Paste(data) => {
+            EventMessage::CrosstermEvent(Event::Paste(data)) => {
                 app.cmdline.insert_str(app.cmdline_position as usize, &data);
                 app.cmdline_position = app.cmdline_position.saturating_add(data.len() as u16);
 
@@ -306,7 +319,13 @@ fn run_app<B: Backend>(
                 }
             }
 
-            Event::FocusGained | Event::FocusLost | Event::Mouse(_) | Event::Resize(_, _) => {}
+            EventMessage::CrosstermEvent(Event::FocusGained)
+            | EventMessage::CrosstermEvent(Event::FocusLost)
+            | EventMessage::CrosstermEvent(Event::Mouse(_))
+            | EventMessage::CrosstermEvent(Event::Resize(_, _)) => {}
+
+            // TODO
+            _ => {}
         }
     }
 }
diff --git a/src/worker.rs b/src/worker.rs
new file mode 100644
index 0000000..e8d475d
--- /dev/null
+++ b/src/worker.rs
@@ -0,0 +1,3 @@
+struct CommandRunner {
+    event_sender: Sender<>
+}