//! Background expiry/retention sweeper. Mirrors the durable-run worker: a single
//! periodic loop that deletes overdue/stale rows so security-relevant tables
//! (auth sessions, oauth states) don't leak credentials and journal/audit tables
//! don't grow unbounded. Best-effort — a failed sweep is logged and retried next
//! tick. The first tick fires immediately on boot.

use std::time::Duration;

use sqlx::PgPool;

use cm_db::repo::cleanup;

// Retention windows (days). Security-relevant rows expire with no grace.
const OUTBOX_SENT_DAYS: i32 = 7;
const RUN_EVENTS_DAYS: i32 = 14; // beyond the live SSE-replay window
const ROUTINE_RUNS_DAYS: i32 = 30;
const TOPOLOGY_RUNS_DAYS: i32 = 90; // user-visible run history
const CONSUMED_GRANTS_DAYS: i32 = 7;

/// Spawn the cleanup sweeper, running every `interval` (e.g. hourly).
pub fn spawn(pool: PgPool, interval: Duration) {
    tokio::spawn(async move {
        let mut tick = tokio::time::interval(interval);
        loop {
            tick.tick().await;
            sweep_once(&pool).await;
        }
    });
}

async fn sweep_once(pool: &PgPool) {
    let steps: [(&str, Result<u64, cm_db::DbError>); 7] = [
        ("auth_sessions", cleanup::expire_auth_sessions(pool).await),
        ("oauth_states", cleanup::expire_oauth_states(pool).await),
        (
            "outbox",
            cleanup::prune_sent_outbox(pool, OUTBOX_SENT_DAYS).await,
        ),
        (
            "run_events",
            cleanup::prune_run_events(pool, RUN_EVENTS_DAYS).await,
        ),
        (
            "routine_runs",
            cleanup::prune_routine_runs(pool, ROUTINE_RUNS_DAYS).await,
        ),
        (
            "topology_runs",
            cleanup::prune_topology_runs(pool, TOPOLOGY_RUNS_DAYS).await,
        ),
        (
            "execution_grants",
            cleanup::prune_consumed_grants(pool, CONSUMED_GRANTS_DAYS).await,
        ),
    ];
    let mut total = 0u64;
    for (table, result) in steps {
        match result {
            Ok(n) => total += n,
            Err(e) => eprintln!("cleanup_sweeper: {table} sweep failed: {e}"),
        }
    }
    if total > 0 {
        eprintln!("cleanup_sweeper: removed {total} stale row(s)");
    }
}