Merge pull request #35 from JakeStanger/feat/script-watch

feat(script): new watch mode

src/modules/script.rs

@@ -1,23 +1,41 @@
 use crate::modules::{Module, ModuleInfo, ModuleUpdateEvent, ModuleWidget, WidgetContext};
 use crate::script::exec_command;
-use color_eyre::Result;
+use color_eyre::{Help, Report, Result};
 use gtk::prelude::*;
 use gtk::Label;
 use serde::Deserialize;
-use tokio::spawn;
+use std::process::Stdio;
+use tokio::io::{AsyncBufReadExt, BufReader};
+use tokio::process::Command;
 use tokio::sync::mpsc::{Receiver, Sender};
 use tokio::time::sleep;
+use tokio::{select, spawn};
 use tracing::error;
 
+#[derive(Debug, Deserialize, Clone, Copy)]
+#[serde(rename_all = "kebab-case")]
+enum Mode {
+    Poll,
+    Watch,
+}
+
 #[derive(Debug, Deserialize, Clone)]
 pub struct ScriptModule {
     /// Path to script to execute.
     path: String,
+    /// Script execution mode
+    #[serde(default = "default_mode")]
+    mode: Mode,
     /// Time in milliseconds between executions.
     #[serde(default = "default_interval")]
     interval: u64,
 }
 
+/// `Mode::Poll`
+const fn default_mode() -> Mode {
+    Mode::Poll
+}
+
 /// 5000ms
 const fn default_interval() -> u64 {
     5000
@@ -35,19 +53,76 @@ impl Module<Label> for ScriptModule {
     ) -> Result<()> {
         let interval = self.interval;
         let path = self.path.clone();
-        spawn(async move {
-            loop {
-                match exec_command(&path) {
-                    Ok(stdout) => tx
-                        .send(ModuleUpdateEvent::Update(stdout))
-                        .await
-                        .expect("Failed to send stdout"),
-                    Err(err) => error!("{:?}", err),
-                }
 
-                sleep(tokio::time::Duration::from_millis(interval)).await;
-            }
-        });
+        match self.mode {
+            Mode::Poll => spawn(async move {
+                loop {
+                    match exec_command(&path) {
+                        Ok(stdout) => tx
+                            .send(ModuleUpdateEvent::Update(stdout))
+                            .await
+                            .expect("Failed to send stdout"),
+                        Err(err) => error!("{:?}", err),
+                    }
+
+                    sleep(tokio::time::Duration::from_millis(interval)).await;
+                }
+            }),
+            Mode::Watch => spawn(async move {
+                loop {
+                    let mut handle = Command::new("sh")
+                        .args(["-c", &path])
+                        .stdout(Stdio::piped())
+                        .stderr(Stdio::piped())
+                        .stdin(Stdio::null())
+                        .spawn()
+                        .expect("Failed to spawn process");
+
+                    let mut stdout_lines = BufReader::new(
+                        handle
+                            .stdout
+                            .take()
+                            .expect("Failed to take script handle stdout"),
+                    )
+                    .lines();
+
+                    let mut stderr_lines = BufReader::new(
+                        handle
+                            .stderr
+                            .take()
+                            .expect("Failed to take script handle stderr"),
+                    )
+                    .lines();
+
+                    loop {
+                        select! {
+                            _ = handle.wait() => break,
+                            Ok(Some(line)) = stdout_lines.next_line() => {
+                                tx.send(ModuleUpdateEvent::Update(line.to_string()))
+                            .await
+                            .expect("Failed to send stdout");
+                            }
+                            Ok(Some(line)) = stderr_lines.next_line() => {
+                                error!("{:?}", Report::msg(line)
+                                    .wrap_err("Watched script error:")
+                                    .suggestion("Check the path to your script")
+                                    .suggestion("Check the script for errors")
+                                    .suggestion("If you expect the script to write to stderr, consider redirecting its output to /dev/null to suppress these messages")
+                                )
+                            }
+                        }
+                    }
+
+                    while let Ok(Some(line)) = stdout_lines.next_line().await {
+                        tx.send(ModuleUpdateEvent::Update(line.to_string()))
+                            .await
+                            .expect("Failed to send stdout");
+                    }
+
+                    sleep(tokio::time::Duration::from_millis(interval)).await;
+                }
+            }),
+        };
 
         Ok(())
     }