yubikey.rs/cli/src/terminal.rs

//! Status messages

use lazy_static::lazy_static;
use std::io::{self, Write};
use std::sync::Mutex;
use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};

/// Print a success status message (in green if colors are enabled)
#[macro_export]
macro_rules! status_ok {
    ($status:expr, $msg:expr) => {
        $crate::terminal::Status::new()
            .justified()
            .bold()
            .color(termcolor::Color::Green)
            .status($status)
            .print_stdout($msg);
    };
    ($status:expr, $fmt:expr, $($arg:tt)+) => {
        $crate::status_ok!($status, format!($fmt, $($arg)+));
    };
}

/// Print a warning status message (in yellow if colors are enabled)
#[macro_export]
macro_rules! status_warn {
    ($msg:expr) => {
        $crate::terminal::Status::new()
            .bold()
            .color(termcolor::Color::Yellow)
            .status("warning:")
            .print_stdout($msg);
    };
    ($fmt:expr, $($arg:tt)+) => {
        $crate::status_warn!(format!($fmt, $($arg)+));
    };
}

/// Print an error message (in red if colors are enabled)
#[macro_export]
macro_rules! status_err {
    ($msg:expr) => {
        $crate::terminal::Status::new()
            .bold()
            .color(termcolor::Color::Red)
            .status("error:")
            .print_stderr($msg);
    };
    ($fmt:expr, $($arg:tt)+) => {
        $crate::status_err!(format!($fmt, $($arg)+));
    };
}

lazy_static! {
    /// Color configuration
    static ref COLOR_CHOICE: Mutex<Option<ColorChoice>> = Mutex::new(None);

    /// Standard output
    pub static ref STDOUT: StandardStream = StandardStream::stdout(get_color_choice());

    /// Standard error
    pub static ref STDERR: StandardStream = StandardStream::stderr(get_color_choice());
}

/// Obtain the color configuration.
///
/// Panics if no configuration has been provided.
fn get_color_choice() -> ColorChoice {
    let choice = COLOR_CHOICE.lock().unwrap();
    *choice
        .as_ref()
        .expect("terminal stream accessed before initialized!")
}

/// Set the color configuration.
///
/// Panics if the terminal has already been configured.
pub(super) fn set_color_choice(color_choice: ColorChoice) {
    let mut choice = COLOR_CHOICE.lock().unwrap();
    assert!(choice.is_none(), "terminal colors already configured!");
    *choice = Some(color_choice);
}

/// Status message builder
#[derive(Clone, Debug, Default)]
pub struct Status {
    /// Should the status be justified?
    justified: bool,

    /// Should colors be bold?
    bold: bool,

    /// Color in which status should be displayed
    color: Option<Color>,

    /// Prefix of the status message (e.g. `Success`)
    status: Option<String>,
}

impl Status {
    /// Create a new status message with default settings
    pub fn new() -> Self {
        Self::default()
    }

    /// Justify status on display
    pub fn justified(mut self) -> Self {
        self.justified = true;
        self
    }

    /// Make colors bold
    pub fn bold(mut self) -> Self {
        self.bold = true;
        self
    }

    /// Set the colors used to display this message
    pub fn color(mut self, c: Color) -> Self {
        self.color = Some(c);
        self
    }

    /// Set a status message to display
    pub fn status<S>(mut self, msg: S) -> Self
    where
        S: ToString,
    {
        self.status = Some(msg.to_string());
        self
    }

    /// Print the given message to stdout
    pub fn print_stdout(self, msg: impl AsRef<str>) {
        self.print(&*STDOUT, msg)
            .expect("error printing to stdout!")
    }

    /// Print the given message to stderr
    pub fn print_stderr(self, msg: impl AsRef<str>) {
        self.print(&*STDERR, msg)
            .expect("error printing to stderr!")
    }

    /// Print the given message
    fn print(self, stream: &StandardStream, msg: impl AsRef<str>) -> io::Result<()> {
        let mut s = stream.lock();
        s.reset()?;
        s.set_color(ColorSpec::new().set_fg(self.color).set_bold(self.bold))?;

        if let Some(status) = self.status {
            if self.justified {
                write!(s, "{:>12}", status)?;
            } else {
                write!(s, "{}", status)?;
            }
        }

        s.reset()?;
        writeln!(s, " {}", msg.as_ref())?;
        s.flush()?;

        Ok(())
    }
}