const billing = require("./billing");

const SETTLEMENT_INTERVAL_MS = 5 * 60 * 1000;
const LEAK_THRESHOLD_MINUTES = 10;

let timerId = null;

async function settleOrphanedLeases() {
  const { pool, withTransaction } = require("./db");
  const now = new Date();
  const leakCutoff = new Date(now.getTime() - LEAK_THRESHOLD_MINUTES * 60 * 1000).toISOString();

  const { rows: releasedUnsettled } = await pool.query(`
    SELECT id FROM key_leases
    WHERE settled = 0 AND released_at IS NOT NULL
  `);

  const { rows: leaked } = await pool.query(
    `
    SELECT id, key_id FROM key_leases
    WHERE settled = 0 AND released_at IS NULL AND leased_at < $1
  `,
    [leakCutoff],
  );

  if (leaked.length > 0) {
    await withTransaction(async (client) => {
      for (const lease of leaked) {
        await client.query("UPDATE key_leases SET released_at = NOW() WHERE id = $1", [lease.id]);
        await client.query(
          "UPDATE api_keys SET active_count = GREATEST(0, active_count - 1) WHERE id = $1",
          [lease.key_id],
        );
      }
    });
  }

  const allOrphaned = [...releasedUnsettled, ...leaked];
  let settled = 0;
  let failed = 0;

  for (const lease of allOrphaned) {
    try {
      await billing.forceSettleLease(lease.id);
      settled++;
    } catch (err) {
      console.error("[settlementWorker] failed to settle lease", lease.id, err.message);
      failed++;
    }
  }

  if (settled > 0 || failed > 0) {
    console.log(
      `[settlementWorker] settled=${settled} failed=${failed} released_unsettled=${releasedUnsettled.length} leaked=${leaked.length}`,
    );
  }
}

function startSettlementWorker() {
  if (timerId) return;

  settleOrphanedLeases().catch((err) => {
    console.error("[settlementWorker] initial run failed", err.message);
  });

  timerId = setInterval(() => {
    settleOrphanedLeases().catch((err) => {
      console.error("[settlementWorker] periodic run failed", err.message);
    });
  }, SETTLEMENT_INTERVAL_MS);

  if (timerId.unref) {
    timerId.unref();
  }

  console.log(
    `[settlementWorker] started (interval=${SETTLEMENT_INTERVAL_MS}ms, leakThreshold=${LEAK_THRESHOLD_MINUTES}min)`,
  );
}

function stopSettlementWorker() {
  if (timerId) {
    clearInterval(timerId);
    timerId = null;
    console.log("[settlementWorker] stopped");
  }
}

module.exports = { startSettlementWorker, stopSettlementWorker, settleOrphanedLeases };