//! systemd daemon-health alert/recovery messages. Domain half of the Alerter
//! split; shared dispatch/cooldown plumbing lives in the parent module.

use tracing::instrument;

use super::{AlertCategory, AlertMeta, Alerter};

impl Alerter {
    /// Fire when a host's watched daemons transition from all-healthy into a
    /// degraded (crash-loop / host-wide failed unit) or down (a watched unit
    /// inactive or unloaded) state. Carries the issue lines that fired.
    #[instrument(skip_all)]
    pub async fn send_systemd_alert(
        &self,
        target: &str,
        label: &str,
        status: &str,
        issues: &[String],
    ) {
        let alert_key = format!("systemd:{target}");
        let subject = format!("[PoM] {label}: daemons {status}");
        let body = format!(
            "Target: {label} ({target})\n\
             Status: {status}\n\
             Issues:\n{}\n\
             Instance: {}\n\
             Time: {}\n\n\
             - PoM",
            issues
                .iter()
                .map(|i| format!("  - {i}"))
                .collect::<Vec<_>>()
                .join("\n"),
            self.instance_name,
            chrono::Utc::now().to_rfc3339(),
        );

        let priority = if status == "down" { "critical" } else { "high" };
        self.fire_failure(
            &subject,
            &body,
            priority,
            "pom-systemd",
            Some(target),
            AlertMeta {
                key: &alert_key,
                category: AlertCategory::SystemdFailure,
                from: None,
                to: Some(status),
                error: None,
            },
        )
        .await;
    }

    /// Fire on recovery, every watched daemon healthy again and no host-wide
    /// failed unit.
    #[instrument(skip_all)]
    pub async fn send_systemd_recovery(&self, target: &str, label: &str) {
        let alert_key = format!("systemd:{target}");
        let subject = format!("[PoM] {label}: daemons recovered");
        let body = format!(
            "Target: {label} ({target})\n\
             All watched daemons are healthy.\n\
             Instance: {}\n\
             Time: {}\n\n\
             - PoM",
            self.instance_name,
            chrono::Utc::now().to_rfc3339(),
        );

        self.fire_recovery(
            &subject,
            &body,
            AlertMeta {
                key: &alert_key,
                category: AlertCategory::SystemdRecovery,
                from: None,
                to: Some("operational"),
                error: None,
            },
        )
        .await;
    }
}