use once_cell::sync::OnceCell;
use ops_sat_rs::config::LOG_FOLDER;
use std::path::{Path, PathBuf};

pub static LOGFILE_PATH: OnceCell<PathBuf> = OnceCell::new();

pub fn setup_logger() -> Result<(), fern::InitError> {
    if !Path::new(LOG_FOLDER).exists() && std::fs::create_dir_all(LOG_FOLDER).is_err() {
        eprintln!("Failed to create log folder '{}'", LOG_FOLDER);
    }
    let mut path_buf = PathBuf::from(LOG_FOLDER);
    path_buf.push(
        format!(
            "output_{}.log",
            humantime::format_rfc3339_seconds(std::time::SystemTime::now())
        )
        .replace(':', "_"),
    );
    println!("Creating logfile {:?}", path_buf);
    LOGFILE_PATH
        .set(path_buf.clone())
        .expect("Error setting global logfile path");
    fern::Dispatch::new()
        .format(move |out, message, record| {
            out.finish(format_args!(
                "[{}][{}][{}] {}",
                humantime::format_rfc3339_millis(std::time::SystemTime::now()),
                std::thread::current().name().unwrap_or("unnamed_thread"),
                record.level(),
                message
            ))
        })
        .level(log::LevelFilter::Debug)
        .chain(std::io::stdout())
        .chain(fern::log_file(path_buf.as_os_str())?)
        .apply()?;
    Ok(())
}