mycelium_core 0.1.1

use std::io;

pub fn setup_logging(verbosity: usize) -> Result<(), fern::InitError> {
    let mut base_config = fern::Dispatch::new();

    base_config = match verbosity {
        0 => {
            // Let's say we depend on something which whose "info" level messages are too
            // verbose to include in end-user output. If we don't need them,
            // let's not include them.
            base_config
                .level(log::LevelFilter::Info)
                .level_for("overly-verbose-target", log::LevelFilter::Warn)
        }
        1 => base_config
            .level(log::LevelFilter::Debug)
            .level_for("overly-verbose-target", log::LevelFilter::Info),
        2 => base_config.level(log::LevelFilter::Debug),
        _3_or_more => base_config.level(log::LevelFilter::Trace),
    };

    // Separate file config so we can include year, month and day in file logs
    let file_config = fern::Dispatch::new()
        .format(|out, message, record| {
            out.finish(format_args!(
                "{}[{}][{}] {}",
                chrono::Local::now().format("[%Y-%m-%d][%H:%M:%S]"),
                record.target(),
                record.level(),
                message
            ))
        })
        .chain(fern::log_file("program.log")?);

    let stdout_config = fern::Dispatch::new()
        .format(|out, message, record| {
            // special format for debug messages coming from our own crate.
            if record.level() > log::LevelFilter::Info && record.target() == "cmd_program" {
                out.finish(format_args!(
                    "---\nDEBUG: {}: {}\n---",
                    chrono::Local::now().format("%H:%M:%S"),
                    message
                ))
            } else {
                out.finish(format_args!(
                    "[{}][{}][{}] {}",
                    chrono::Local::now().format("%H:%M"),
                    record.target(),
                    record.level(),
                    message
                ))
            }
        })
        .chain(io::stdout());

    base_config
        .chain(file_config)
        .chain(stdout_config)
        .apply()?;

    Ok(())
}