use std::{env, fs, io, result::Result, str::FromStr};

use docker_registry::{reference, v2::manifest::Manifest};
use tracing::{error, info, warn};

#[tokio::main]
async fn main() {
  tracing_subscriber::fmt()
    .pretty()
    .with_max_level(tracing::Level::INFO)
    .init();

  let dkr_ref = match std::env::args().nth(1) {
    Some(ref x) => reference::Reference::from_str(x),
    None => reference::Reference::from_str("quay.io/steveej/cincinnati-test-labels:0.0.0"),
  }
  .unwrap();
  let registry = dkr_ref.registry();

  info!("[{registry}] downloading image {dkr_ref}");

  let mut user = None;
  let mut password = None;
  let home = dirs::home_dir().unwrap();
  let cfg = fs::File::open(home.join(".docker/config.json"));
  if let Ok(fp) = cfg {
    let creds = docker_registry::get_credentials(io::BufReader::new(fp), &registry);
    if let Ok(user_pass) = creds {
      user = user_pass.0;
      password = user_pass.1;
    } else {
      warn!("[{registry}] no credentials found in config.json");
    }
  } else {
    user = env::var("DOCKER_REGISTRY_USER").ok();
    if user.is_none() {
      warn!("[{registry}] no $DOCKER_REGISTRY_USER for login user");
    }
    password = env::var("DOCKER_REGISTRY_PASSWD").ok();
    if password.is_none() {
      warn!("[{registry}] no $DOCKER_REGISTRY_PASSWD for login password");
    }
  };

  let res = run(&dkr_ref, user, password).await;

  if let Err(e) = res {
    error!("[{registry}] {e}");
    std::process::exit(1);
  };
}

async fn run(
  dkr_ref: &reference::Reference,
  user: Option<String>,
  passwd: Option<String>,
) -> Result<(), docker_registry::errors::Error> {
  let client = docker_registry::v2::Client::configure()
    .registry(&dkr_ref.registry())
    .insecure_registry(false)
    .username(user)
    .password(passwd)
    .build()?;

  let image = dkr_ref.repository();
  let login_scope = format!("repository:{image}:pull");
  let version = dkr_ref.version();

  let client = client.authenticate(&[&login_scope]).await?;
  let manifest = client.get_manifest(&image, &version).await?;

  if let Manifest::S1Signed(s1s) = manifest {
    let labels = s1s.get_labels(0);
    info!("got labels: {:#?}", labels);
  } else {
    info!("got no labels");
  }

  Ok(())
}