use kube_leader_election::{LeaseLock, LeaseLockParams};
use std::time::Duration;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    std::env::set_var(
        "RUST_LOG",
        std::env::var("RUST_LOG").unwrap_or_else(|_| "info".to_string()),
    );
    env_logger::init();

    // Configure the LeaseLock mechanism
    //
    // One should try to renew/acquire the lease before `lease_ttl` runs out.
    // E.g. if `lease_ttl` is set to 15 seconds, one should renew it every 5 seconds.
    let leadership = LeaseLock::new(
        kube::Client::try_default().await?,
        "default",
        LeaseLockParams {
            holder_id: "simple-lease".into(),
            lease_name: "simple-lease-example".into(),
            lease_ttl: Duration::from_secs(15),
        },
    );

    // Run this in a background task and share the result with the rest of your application
    let _lease = leadership.try_acquire_or_renew().await?;
    // `lease.acquired_lease` can be used to determine if we're leading or not

    log::info!("waiting 5 seconds, then stepping down again");
    tokio::time::sleep(Duration::from_secs(5)).await;

    // To give up leadership, call `step_down`.
    //
    // This will set the current ttl on the lease to 1s and remove the current holder identity,
    // so all other candidates start to race for the lock on the lease.
    leadership.step_down().await?;

    Ok(())
}