use color_eyre::eyre::Result;
use std::env;
use tracing_error::ErrorLayer;
use tracing_subscriber::{filter::LevelFilter, fmt, prelude::*, EnvFilter};

pub fn install() -> Result<LevelFilter> {
    let fmt_layer = fmt::layer();

    let (filter_layer, current_filter) = match EnvFilter::try_from_default_env() {
        Err(_) => (EnvFilter::try_new("off").unwrap(), LevelFilter::OFF),
        Ok(layer) => {
            let level = layer.max_level_hint().unwrap_or(LevelFilter::OFF);
            (layer, level)
        }
    };

    let registry = tracing_subscriber::registry()
        .with(filter_layer)
        .with(ErrorLayer::default());

    if current_filter == LevelFilter::OFF {
        registry.with(fmt_layer.without_time()).init()
    } else {
        registry.with(fmt_layer).init()
    }

    if env::var("RUST_BACKTRACE").is_err() && current_filter == LevelFilter::TRACE {
        env::set_var("RUST_BACKTRACE", "1");
    }

    let debug = current_filter >= LevelFilter::DEBUG;

    color_eyre::config::HookBuilder::new()
        .capture_span_trace_by_default(debug)
        .display_location_section(debug)
        .display_env_section(false)
        .install()?;

    Ok(current_filter)
}