//! Prometheus metrics for the server.
//!
//! All counters/histograms/gauges use the `metrics` crate and are exported
//! via metrics-exporter-prometheus on a configurable HTTP port (e.g. /metrics).

/// Record one enqueue (success). Call after a message is enqueued.
pub fn record_enqueue_total() {
    metrics::counter!("enqueue_total").increment(1);
}

/// Record enqueued payload size in bytes.
pub fn record_enqueue_bytes(bytes: u64) {
    metrics::counter!("enqueue_bytes_total").increment(bytes);
}

/// Record one fetch (success). Call when fetch returns.
pub fn record_fetch_total() {
    metrics::counter!("fetch_total").increment(1);
}

/// Record one fetch_wait (success). Call when fetch_wait returns.
pub fn record_fetch_wait_total() {
    metrics::counter!("fetch_wait_total").increment(1);
}

/// Set the delivery queue depth gauge (sample). Updated at enqueue/fetch time.
pub fn record_delivery_queue_depth(depth: usize) {
    metrics::gauge!("delivery_queue_depth").set(depth as f64);
}

/// Record one KeyPackage upload (success).
pub fn record_key_package_upload_total() {
    metrics::counter!("key_package_upload_total").increment(1);
}

/// Record successful auth login (session token issued).
pub fn record_auth_login_success_total() {
    metrics::counter!("auth_login_success_total").increment(1);
}

/// Record failed auth login attempt.
pub fn record_auth_login_failure_total() {
    metrics::counter!("auth_login_failure_total").increment(1);
}

/// Record rate limit hit (enqueue rejected).
pub fn record_rate_limit_hit_total() {
    metrics::counter!("rate_limit_hit_total").increment(1);
}