use prometheus_exporter_base::prelude::*;
use std::{fs::read_dir, net::SocketAddr};

#[derive(Debug, Clone, Default)]
struct MyOptions {}

fn calculate_file_size(path: &str) -> Result<u64, std::io::Error> {
    let mut total_size: u64 = 0;
    for entry in read_dir(path)? {
        let p = entry?.path();
        if p.is_file() {
            total_size += p.metadata()?.len();
        }
    }

    Ok(total_size)
}

#[tokio::main]
async fn main() {
    env_logger::init();

    let addr: SocketAddr = ([0, 0, 0, 0], 32221).into();
    let password = "SimplePassword".to_owned();

    let server_options = ServerOptions {
        addr,
        authorization: Authorization::Basic(password),
    };
    println!("starting exporter with options {:?}", addr);

    render_prometheus(
        server_options,
        MyOptions::default(),
        |request, options| async move {
            println!(
                "in our render_prometheus(request == {:?}, options == {:?})",
                request, options
            );

            let total_size_log = calculate_file_size("/var/log").unwrap();

            Ok(PrometheusMetric::build()
                .with_name("folder_size")
                .with_metric_type(MetricType::Counter)
                .with_help("Size of the folder")
                .build()
                .render_and_append_instance(
                    &PrometheusInstance::new()
                        .with_label("folder", "/var/log")
                        .with_value(total_size_log)
                        .with_current_timestamp()
                        .expect("error getting the UNIX epoch"),
                )
                .render())
        },
    )
    .await;
}