import { applyPromotion, listPromotionCandidates } from '../models/psadtModel.js';
import { getGraphConnectionSystem } from '../models/graphModel.js';
import { setRingIntent } from './intunePromotionService.js';
import { buildAssignmentsPayload } from './intunePublishService.js';
import { assignWin32App } from './graphService.js';
import { logger } from './logger.js';

// Scheduled auto-promotion: after a deployment's soak window elapses, advance
// its configured rollout ring's intent. When the linked Graph connection is
// write-enabled and not approval-gated, the new assignments are also pushed to
// the tenant; otherwise the plan is promoted and an operator pushes it.

// Pure eligibility decision so the timing logic is unit-tested.
export function evaluatePromotion(deployment, nowMs = Date.now()) {
  const hours = Number(deployment.autoPromoteAfterHours) || 0;
  if (hours <= 0) return { due: false, reason: 'auto-promote disabled' };
  if (!deployment.autoPromoteRing) return { due: false, reason: 'no target ring' };
  if (deployment.promotedAt) return { due: false, reason: 'already promoted' };
  if (!deployment.soakStartedAt) return { due: false, reason: 'soak not started' };
  const soakStart = Date.parse(deployment.soakStartedAt);
  if (Number.isNaN(soakStart)) return { due: false, reason: 'invalid soak timestamp' };
  const elapsedHours = (nowMs - soakStart) / 3_600_000;
  if (elapsedHours < hours) return { due: false, reason: `soaking (${elapsedHours.toFixed(1)}/${hours}h)` };
  return { due: true, reason: 'soak window elapsed' };
}

export async function runAutoPromotions({ nowMs = Date.now(), pusher = assignWin32App } = {}) {
  const summary = { evaluated: 0, promoted: 0, pushed: 0, errors: 0 };
  for (const deployment of listPromotionCandidates()) {
    summary.evaluated += 1;
    const decision = evaluatePromotion(deployment, nowMs);
    if (!decision.due) continue;
    try {
      const { assignments, changed } = setRingIntent(deployment.assignments, deployment.autoPromoteRing, deployment.autoPromoteIntent);
      applyPromotion(deployment.id, changed ? assignments : deployment.assignments);
      summary.promoted += 1;

      // Optionally push to the tenant when it is safe to do so automatically.
      if (deployment.graphAppId && deployment.graphConnectionId) {
        const connection = getGraphConnectionSystem(deployment.graphConnectionId);
        if (connection?.allow_write && !connection?.require_approval) {
          const built = buildAssignmentsPayload({ ...deployment, assignments });
          await pusher(connection, deployment.graphAppId, built.assignments);
          summary.pushed += 1;
        }
      }
    } catch (error) {
      summary.errors += 1;
      logger.error('auto-promotion failed', { deploymentId: deployment.id, error: error.message });
    }
  }
  return summary;
}

let timer = null;

export function startPromotionWorker() {
  const minutes = Number(process.env.AUTO_PROMOTE_INTERVAL_MINUTES || 0);
  if (!Number.isFinite(minutes) || minutes <= 0) return null;
  timer = setInterval(() => {
    runAutoPromotions()
      .then((summary) => logger.info('auto-promotion run complete', summary))
      .catch((error) => logger.error('auto-promotion run failed', { error: error.message }));
  }, minutes * 60 * 1000);
  timer.unref?.();
  logger.info(`auto-promotion scheduled every ${minutes} minute(s)`);
  return timer;
}

export function stopPromotionWorker() {
  if (timer) clearInterval(timer);
  timer = null;
}