#!/usr/bin/env node
/**
 * sync-sources.mjs — keep the kustomization mirror in sync with the
 * source-of-truth config files (TASK-0135, phase-15).
 *
 * kustomize's configMapGenerator cannot read files outside the
 * kustomization's directory, so infrastructure/kubernetes/observability/
 * carries MIRROR copies of the files authored in
 * infrastructure/observability/. This script is the guard:
 *
 *   node infrastructure/kubernetes/observability/scripts/sync-sources.mjs          # check (CI)
 *   node .../sync-sources.mjs --write                                              # re-mirror after editing sources
 *
 * Exit 0 = in sync, 1 = drift (check mode) or failure.
 */
import { copyFileSync, existsSync, readFileSync } from "node:fs";
import { dirname, join, relative } from "node:path";
import { fileURLToPath } from "node:url";

const here = dirname(fileURLToPath(import.meta.url));
const kdir = join(here, ".."); // infrastructure/kubernetes/observability
const sdir = join(here, "..", "..", "..", "observability"); // infrastructure/observability

const PAIRS = [
  ["prometheus/scrape.yaml", "prometheus/scrape.yaml"],
  ["prometheus/recording-rules.yaml", "prometheus/recording-rules.yaml"],
  ["prometheus/alerts.yaml", "prometheus/alerts.yaml"],
  ["alertmanager/alertmanager.yaml", "alertmanager/alertmanager.yaml"],
  ["grafana/provisioning/datasources/datasource.yaml", "grafana/provisioning/datasources/datasource.yaml"],
  ["grafana/provisioning/dashboards/dashboards.yaml", "grafana/provisioning/dashboards/dashboards.yaml"],
  ["grafana/dashboards/api-overview.json", "grafana/dashboards/api-overview.json"],
  ["grafana/dashboards/realtime.json", "grafana/dashboards/realtime.json"],
  ["grafana/dashboards/workers-queues.json", "grafana/dashboards/workers-queues.json"],
  ["grafana/dashboards/search.json", "grafana/dashboards/search.json"],
  ["grafana/dashboards/ai.json", "grafana/dashboards/ai.json"],
  ["grafana/dashboards/infra.json", "grafana/dashboards/infra.json"]
];

const write = process.argv.includes("--write");
let bad = 0;

for (const [srcRel, mirrorRel] of PAIRS) {
  const src = join(sdir, srcRel);
  const mirror = join(kdir, mirrorRel);
  if (!existsSync(src)) {
    console.error(`MISSING SOURCE: ${srcRel}`);
    bad++;
    continue;
  }
  if (!existsSync(mirror) || readFileSync(src, "utf8") !== readFileSync(mirror, "utf8")) {
    if (write) {
      copyFileSync(src, mirror);
      console.log(`re-mirrored ${mirrorRel}`);
    } else {
      console.error(`DRIFT: ${mirrorRel} != ${srcRel}`);
      bad++;
    }
  }
}

if (write && bad === 0) {
  console.log("OK: mirror is in sync (write mode)");
} else if (bad === 0) {
  console.log(`OK: ${PAIRS.length} mirror files are in sync with infrastructure/observability/`);
} else {
  console.error(`${bad} file(s) out of sync — run: node ${relative(process.cwd(), join(here, "sync-sources.mjs"))} --write`);
  process.exit(1);
}