balise-cli 0.1.0-alpha.3

//! The Balise CLI of one version. Users run it through `balise`, which picks the version of
//! their project.

use std::io::{IsTerminal, Write};
use std::process::ExitCode;

use balise_cli::{Context, Outcome, System, execute, person_at_terminal, style};

fn main() -> ExitCode {
    let args: Vec<String> = std::env::args().skip(1).collect();
    let stdin = std::io::stdin();
    let mut input = stdin.lock();
    let mut questions = std::io::stderr();
    let mut context = Context {
        cwd: std::env::current_dir().unwrap_or_default(),
        interactive: person_at_terminal(),
        input: &mut input,
        output: &mut questions,
        // Questions go to standard error, results to standard output: both must be a terminal.
        color: style::wanted(std::io::stdout().is_terminal())
            && style::wanted(std::io::stderr().is_terminal()),
        machine: &System,
    };
    let json = args.iter().any(|arg| arg == "--json");
    let Outcome {
        text: out,
        exit,
        failed,
    } = execute(&args, &mut context);
    // A result goes to standard output, as JSON for programs, even when it ends in failure
    // (`balise check` finding errors); an error otherwise goes to standard error.
    match (failed, json) {
        // A hook says what it has to say on standard error, itself.
        (false, _) if out.is_empty() => {}
        (_, true) => println!("{out}"),
        (false, false) => match style::wanted(std::io::stdout().is_terminal()) {
            true => println!("{}", style::colorize(&out)),
            false => println!("{out}"),
        },
        (true, false) => {
            let (label, out) = match style::wanted(std::io::stderr().is_terminal()) {
                true => (style::error_label(), style::colorize(&out)),
                false => ("error".to_string(), out),
            };
            let _ = writeln!(std::io::stderr(), "{label} {out}");
        }
    }
    ExitCode::from(exit)
}