feat: common module options (show_if, on_click, tooltip)

The first three of many options that are common to all modules.

Resolves #36. Resolves partially #34.

src/script.rs

@@ -1,36 +1,354 @@
 use color_eyre::eyre::WrapErr;
-use color_eyre::{Help, Report, Result};
-use std::process::Command;
-use tracing::instrument;
+use color_eyre::{Report, Result};
+use serde::Deserialize;
+use std::fmt::{Display, Formatter};
+use std::process::Stdio;
+use tokio::io::{AsyncBufReadExt, BufReader};
+use tokio::process::Command;
+use tokio::sync::mpsc;
+use tokio::time::sleep;
+use tokio::{select, spawn};
+use tracing::{error, warn};
 
-/// Attempts to execute a given command,
-/// waiting for it to finish.
-/// If the command returns status 0,
-/// the `stdout` is returned.
-/// Otherwise, an `Err` variant
-/// containing the `stderr` is returned.
-#[instrument]
-pub fn exec_command(command: &str) -> Result<String> {
-    let output = Command::new("sh")
-        .arg("-c")
-        .arg(command)
-        .output()
-        .wrap_err("Failed to get script output")?;
+#[derive(Debug, Deserialize, Clone)]
+#[serde(untagged)]
+pub enum ScriptInput {
+    String(String),
+    Struct(Script),
+}
 
-    if output.status.success() {
-        let stdout = String::from_utf8(output.stdout)
-            .map(|output| output.trim().to_string())
-            .wrap_err("Script stdout not valid UTF-8")?;
+#[derive(Debug, Deserialize, Clone, Copy, Eq, PartialEq)]
+#[serde(rename_all = "snake_case")]
+pub enum ScriptMode {
+    Poll,
+    Watch,
+}
 
-        Ok(stdout)
-    } else {
-        let stderr = String::from_utf8(output.stderr)
-            .map(|output| output.trim().to_string())
-            .wrap_err("Script stderr not valid UTF-8")?;
+#[derive(Debug, Clone)]
+pub enum OutputStream {
+    Stdout(String),
+    Stderr(String),
+}
 
-        Err(Report::msg(stderr)
-            .wrap_err("Script returned non-zero error code")
-            .suggestion("Check the path to your script")
-            .suggestion("Check the script for errors"))
+impl From<&str> for ScriptMode {
+    fn from(str: &str) -> Self {
+        match str {
+            "poll" | "p" => Self::Poll,
+            "watch" | "w" => Self::Watch,
+            _ => {
+                warn!("Invalid script mode: '{str}', falling back to polling");
+                ScriptMode::Poll
+            }
+        }
+    }
+}
+
+impl Default for ScriptMode {
+    fn default() -> Self {
+        Self::Poll
+    }
+}
+
+impl Display for ScriptMode {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                ScriptMode::Poll => "poll",
+                ScriptMode::Watch => "watch",
+            }
+        )
+    }
+}
+
+impl ScriptMode {
+    fn try_parse(str: &str) -> Result<Self> {
+        match str {
+            "poll" | "p" => Ok(Self::Poll),
+            "watch" | "w" => Ok(Self::Watch),
+            _ => Err(Report::msg(format!("Invalid script mode: {str}"))),
+        }
+    }
+}
+
+#[derive(Debug, Deserialize, Clone)]
+pub struct Script {
+    #[serde(default = "ScriptMode::default")]
+    pub(crate) mode: ScriptMode,
+    pub cmd: String,
+    #[serde(default = "default_interval")]
+    pub(crate) interval: u64,
+}
+
+const fn default_interval() -> u64 {
+    5000
+}
+
+impl Default for Script {
+    fn default() -> Self {
+        Self {
+            mode: ScriptMode::default(),
+            interval: default_interval(),
+            cmd: String::new(),
+        }
+    }
+}
+
+impl From<ScriptInput> for Script {
+    fn from(input: ScriptInput) -> Self {
+        match input {
+            ScriptInput::String(string) => Self::from(string.as_str()),
+            ScriptInput::Struct(script) => script,
+        }
+    }
+}
+
+#[derive(Debug)]
+enum ScriptInputToken {
+    Mode(ScriptMode),
+    Interval(u64),
+    Cmd(String),
+    Colon,
+}
+
+impl From<&str> for Script {
+    fn from(str: &str) -> Self {
+        let mut script = Self::default();
+        let mut tokens = vec![];
+
+        let mut chars = str.chars().collect::<Vec<_>>();
+        while !chars.is_empty() {
+            let char = chars[0];
+
+            let (token, skip) = match char {
+                ':' => (ScriptInputToken::Colon, 1),
+                // interval
+                '0'..='9' => {
+                    let interval_str = chars
+                        .iter()
+                        .take_while(|c| c.is_ascii_digit())
+                        .collect::<String>();
+                    (
+                        ScriptInputToken::Interval(
+                            interval_str.parse::<u64>().expect("Invalid interval"),
+                        ),
+                        interval_str.len(),
+                    )
+                }
+                // watching or polling
+                'w' | 'p' => {
+                    let mode_str = chars.iter().take_while(|&c| c != &':').collect::<String>();
+                    let len = mode_str.len();
+
+                    let token = ScriptMode::try_parse(&mode_str)
+                        .map_or(ScriptInputToken::Cmd(mode_str), |mode| {
+                            ScriptInputToken::Mode(mode)
+                        });
+
+                    (token, len)
+                }
+                _ => {
+                    let cmd_str = chars.iter().take_while(|_| true).collect::<String>();
+                    let len = cmd_str.len();
+                    (ScriptInputToken::Cmd(cmd_str), len)
+                }
+            };
+
+            tokens.push(token);
+            chars.drain(..skip);
+        }
+
+        for token in tokens {
+            match token {
+                ScriptInputToken::Mode(mode) => script.mode = mode,
+                ScriptInputToken::Interval(interval) => script.interval = interval,
+                ScriptInputToken::Cmd(cmd) => script.cmd = cmd,
+                ScriptInputToken::Colon => {}
+            }
+        }
+
+        script
+    }
+}
+
+impl Script {
+    pub fn new_polling(input: ScriptInput) -> Self {
+        let mut script = Self::from(input);
+        script.mode = ScriptMode::Poll;
+        script
+    }
+
+    pub async fn run<F>(&self, callback: F)
+    where
+        F: Fn((OutputStream, bool)),
+    {
+        loop {
+            match self.mode {
+                ScriptMode::Poll => match self.get_output().await {
+                    Ok(output) => callback(output),
+                    Err(err) => error!("{err:?}"),
+                },
+                ScriptMode::Watch => match self.spawn().await {
+                    Ok(mut rx) => {
+                        while let Some(msg) = rx.recv().await {
+                            callback((msg, true));
+                        }
+                    }
+                    Err(err) => error!("{err:?}"),
+                },
+            };
+
+            sleep(tokio::time::Duration::from_millis(self.interval)).await;
+        }
+    }
+
+    /// Attempts to execute a given command,
+    /// waiting for it to finish.
+    /// If the command returns status 0,
+    /// the `stdout` is returned.
+    /// Otherwise, an `Err` variant
+    /// containing the `stderr` is returned.
+    pub async fn get_output(&self) -> Result<(OutputStream, bool)> {
+        let output = Command::new("sh")
+            .args(["-c", &self.cmd])
+            .output()
+            .await
+            .wrap_err("Failed to get script output")?;
+
+        if output.status.success() {
+            let stdout = String::from_utf8(output.stdout)
+                .map(|output| output.trim().to_string())
+                .wrap_err("Script stdout not valid UTF-8")?;
+
+            Ok((OutputStream::Stdout(stdout), true))
+        } else {
+            let stderr = String::from_utf8(output.stderr)
+                .map(|output| output.trim().to_string())
+                .wrap_err("Script stderr not valid UTF-8")?;
+
+            Ok((OutputStream::Stderr(stderr), false))
+        }
+    }
+
+    pub async fn spawn(&self) -> Result<mpsc::Receiver<OutputStream>> {
+        let mut handle = Command::new("sh")
+            .args(["-c", &self.cmd])
+            .stdout(Stdio::piped())
+            .stderr(Stdio::piped())
+            .stdin(Stdio::null())
+            .spawn()?;
+
+        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();
+
+        let (tx, rx) = mpsc::channel(32);
+
+        spawn(async move {
+            loop {
+                select! {
+                    _ = handle.wait() => break,
+                    Ok(Some(line)) = stdout_lines.next_line() => {
+                        tx.send(OutputStream::Stdout(line)).await.expect("Failed to send stdout");
+                    }
+                    Ok(Some(line)) = stderr_lines.next_line() => {
+                        tx.send(OutputStream::Stderr(line)).await.expect("Failed to send stderr");
+                    }
+                }
+            }
+        });
+
+        Ok(rx)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_basic() {
+        let cmd = "echo 'hello'";
+        let script = Script::from(cmd);
+
+        assert_eq!(script.cmd, cmd);
+        assert_eq!(script.interval, default_interval());
+        assert_eq!(script.mode, ScriptMode::default());
+    }
+
+    #[test]
+    fn test_parse_full() {
+        let cmd = "echo 'hello'";
+        let mode = ScriptMode::Watch;
+        let interval = 300;
+
+        let full_cmd = format!("{mode}:{interval}:{cmd}");
+        let script = Script::from(full_cmd.as_str());
+
+        assert_eq!(script.cmd, cmd);
+        assert_eq!(script.mode, mode);
+        assert_eq!(script.interval, interval);
+    }
+
+    #[test]
+    fn test_parse_interval_and_cmd() {
+        let cmd = "echo 'hello'";
+        let interval = 300;
+
+        let full_cmd = format!("{interval}:{cmd}");
+        let script = Script::from(full_cmd.as_str());
+
+        assert_eq!(script.cmd, cmd);
+        assert_eq!(script.interval, interval);
+        assert_eq!(script.mode, ScriptMode::default());
+    }
+
+    #[test]
+    fn test_parse_mode_and_cmd() {
+        let cmd = "echo 'hello'";
+        let mode = ScriptMode::Watch;
+
+        let full_cmd = format!("{mode}:{cmd}");
+        let script = Script::from(full_cmd.as_str());
+
+        assert_eq!(script.cmd, cmd);
+        assert_eq!(script.interval, default_interval());
+        assert_eq!(script.mode, mode);
+    }
+
+    #[test]
+    fn test_parse_cmd_with_colon() {
+        let cmd = "uptime | awk '{print \"Uptime: \" $1}'";
+        let script = Script::from(cmd);
+
+        assert_eq!(script.cmd, cmd);
+        assert_eq!(script.interval, default_interval());
+        assert_eq!(script.mode, ScriptMode::default());
+    }
+
+    #[test]
+    fn test_no_cmd() {
+        let mode = ScriptMode::Watch;
+        let interval = 300;
+
+        let full_cmd = format!("{mode}:{interval}");
+        let script = Script::from(full_cmd.as_str());
+
+        assert_eq!(script.cmd, ""); // TODO: Probably better handle this case
+        assert_eq!(script.interval, interval);
+        assert_eq!(script.mode, mode);
     }
 }