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pt/members/libpt-cli/src/args.rs

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//! Utilities for parsing options and arguments on the start of a CLI application
use clap::Parser;
#[cfg(feature = "log")]
use libpt_log::Level;
#[cfg(feature = "log")]
use log;
/// Custom help template for displaying command-line usage information
///
/// This template modifies the default template provided by Clap to include additional information
/// and customize the layout of the help message.
///
/// Differences from the default template:
/// - Includes the application version and author information at the end
///
/// Apply like this:
/// ```
/// # use libpt_cli::args::HELP_TEMPLATE;
/// use clap::Parser;
/// #[derive(Parser, Debug, Clone, PartialEq, Eq, Hash)]
/// #[command(help_template = HELP_TEMPLATE)]
/// pub struct MyArgs {
/// /// show more details
/// #[arg(short, long)]
/// pub verbose: bool,
/// }
/// ```
///
/// ## Example
///
/// Don't forget to set `authors` in your `Cargo.toml`!
///
/// ```bash
/// $ cargo run -- -h
/// about: short
///
/// Usage: aaa [OPTIONS]
///
/// Options:
/// -v, --verbose show more details
/// -h, --help Print help (see more with '--help')
/// -V, --version Print version
///
/// aaa: 0.1.0
/// Author: Christoph J. Scherr <software@cscherr.de>
///
/// ```
pub const HELP_TEMPLATE: &str = r#"{about-section}
{usage-heading} {usage}
{all-args}{tab}
{name}: {version}
Author: {author-with-newline}
"#;
/// Transform -v and -q flags to some kind of loglevel
///
/// # Example
///
/// Include this into your [clap] derive struct like this:
///
/// ```
/// use libpt_cli::args::VerbosityLevel;
/// use clap::Parser;
///
/// #[derive(Parser, Debug)]
/// pub struct Opts {
/// #[command(flatten)]
/// pub verbose: VerbosityLevel,
/// #[arg(short, long)]
/// pub mynum: usize,
/// }
///
/// ```
///
/// Get the loglevel like this:
///
/// ```no_run
/// # use libpt_cli::args::VerbosityLevel;
/// use libpt_log::Level;
/// # use clap::Parser;
/// use log;
///
/// # #[derive(Parser, Debug)]
/// # pub struct Opts {
/// # #[command(flatten)]
/// # pub verbose: VerbosityLevel,
/// # }
///
/// fn main() {
/// let opts = Opts::parse();
///
/// // Level might be None if the user wants no output at all.
/// // for the 'tracing' level:
/// let level: Option<Level> = opts.verbose.level();
/// // for the 'log' level:
/// let llevel: Option<log::Level> = opts.verbose.level_for_log_crate();
/// }
/// ```
#[derive(Parser, Clone, PartialEq, Eq, Hash)]
#[cfg(feature = "log")]
pub struct VerbosityLevel {
/// make the output more verbose
#[arg(
long,
short = 'v',
action = clap::ArgAction::Count,
global = true,
// help = L::verbose_help(),
// long_help = L::verbose_long_help(),
)]
verbose: u8,
/// make the output less verbose
///
/// ( -qqq for completely quiet)
#[arg(
long,
short = 'q',
action = clap::ArgAction::Count,
global = true,
conflicts_with = "verbose",
)]
quiet: u8,
}
impl VerbosityLevel {
/// true only if no verbose and no quiet was set (user is using defaults)
#[inline]
pub fn changed(&self) -> bool {
self.verbose != 0 || self.quiet != 0
}
#[inline]
fn value(&self) -> i8 {
let v = Self::level_value(Level::INFO) - (self.quiet as i8) + (self.verbose as i8);
if v > Self::level_value(Level::TRACE) {
Self::level_value(Level::TRACE)
} else {
v
}
}
/// get the [Level] for that VerbosityLevel
///
/// [None] means that absolutely no output is wanted (completely quiet)
#[inline]
pub fn level(&self) -> Option<Level> {
Some(match self.value() {
0 => Level::ERROR,
1 => Level::WARN,
2 => Level::INFO,
3 => Level::DEBUG,
4 => Level::TRACE,
_ => return None,
})
}
/// get the [log::Level] for that VerbosityLevel
///
/// This is the method for the [log] crate, which I use less often.
///
/// [None] means that absolutely no output is wanted (completely quiet)
#[inline]
pub fn level_for_log_crate(&self) -> Option<log::Level> {
self.level().map(|ll| match ll {
Level::TRACE => log::Level::Trace,
Level::DEBUG => log::Level::Debug,
Level::INFO => log::Level::Info,
Level::WARN => log::Level::Warn,
Level::ERROR => log::Level::Error,
})
}
#[inline]
fn level_value(level: Level) -> i8 {
match level {
Level::TRACE => 4,
Level::DEBUG => 3,
Level::INFO => 2,
Level::WARN => 1,
Level::ERROR => 0,
}
}
}
impl std::fmt::Debug for VerbosityLevel {
#[inline]
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{:?}", self.level())
}
}