wash-cli 0.16.1

//! A temporary module to parse NATS credsfiles and translate
//! their contents into a JWT and Seed value
use std::path::Path;

use anyhow::{anyhow, Result};
use regex::Regex;
use tokio::fs::read_to_string;

type Jwt = String;
type Seed = String;

// The code below is largely copied from https://github.com/nats-io/nats.rs/blob/main/async-nats/src/auth_utils.rs
// This is a temporary solution to the fact that a host does not support credsfile authentication

/// Helper function to parse a credsfile from a path and return a tuple
/// with the JWT and Seed values that were in the credsfile
pub(crate) async fn parse_credsfile<P>(path: P) -> Result<(Jwt, Seed)>
where
    P: AsRef<Path>,
{
    let contents = read_to_string(path).await?;
    let jwt = parse_decorated_jwt(&contents)?;
    let seed = parse_decorated_nkey(&contents)?;

    Ok((jwt, seed))
}

fn user_config_re() -> Result<Regex> {
    Ok(Regex::new(
        r"\s*(?:(?:[-]{3,}.*[-]{3,}\r?\n)([\w\-.=]+)(?:\r?\n[-]{3,}.*[-]{3,}\r?\n))",
    )?)
}

/// Parses a credentials file and returns its user JWT.
fn parse_decorated_jwt(contents: &str) -> Result<String> {
    let capture = user_config_re()?
        .captures_iter(contents)
        .next()
        .ok_or_else(|| anyhow!("cannot parse user JWT from the credentials file"))?;
    Ok(capture[1].to_string())
}

/// Parses a credentials file and returns its nkey.
fn parse_decorated_nkey(contents: &str) -> Result<String> {
    let capture = user_config_re()?
        .captures_iter(contents)
        .nth(1)
        .ok_or_else(|| anyhow!("cannot parse user seed from the credentials file"))?;
    Ok(capture[1].to_string())
}