/**
 * Aggregation helper that surfaces advisory_raw duplicate candidates prior to enabling the
 * idempotency unique index. Intended for staging/offline snapshots.
 *
 * Usage:
 *   mongo concelier ops/devops/scripts/check-advisory-raw-duplicates.js
 *
 * Environment variables:
 *   LIMIT - optional cap on number of duplicate groups to print (default 50).
 */
(function () {
  function toInt(value, fallback) {
    var parsed = parseInt(value, 10);
    return Number.isFinite(parsed) && parsed > 0 ? parsed : fallback;
  }

  var limit = typeof LIMIT !== "undefined" ? toInt(LIMIT, 50) : 50;
  var database = db.getName ? db.getSiblingDB(db.getName()) : db;
  if (!database) {
    throw new Error("Unable to resolve database handle");
  }

  print("");
  print("== advisory_raw duplicate audit ==");
  print("Database: " + database.getName());
  print("Limit   : " + limit);
  print("");

  var pipeline = [
    {
      $group: {
        _id: {
          vendor: "$source.vendor",
          upstreamId: "$upstream.upstream_id",
          contentHash: "$upstream.content_hash",
          tenant: "$tenant"
        },
        ids: { $addToSet: "$_id" },
        count: { $sum: 1 }
      }
    },
    { $match: { count: { $gt: 1 } } },
    {
      $project: {
        _id: 0,
        vendor: "$_id.vendor",
        upstreamId: "$_id.upstreamId",
        contentHash: "$_id.contentHash",
        tenant: "$_id.tenant",
        count: 1,
        ids: 1
      }
    },
    { $sort: { count: -1, vendor: 1, upstreamId: 1 } },
    { $limit: limit }
  ];

  var cursor = database.getCollection("advisory_raw").aggregate(pipeline, { allowDiskUse: true });
  var any = false;
  while (cursor.hasNext()) {
    var doc = cursor.next();
    any = true;
    print("---");
    print("vendor      : " + doc.vendor);
    print("upstream_id : " + doc.upstreamId);
    print("tenant      : " + doc.tenant);
    print("content_hash: " + doc.contentHash);
    print("count       : " + doc.count);
    print("ids         : " + doc.ids.join(", "));
  }

  if (!any) {
    print("No duplicate advisory_raw documents detected.");
  }

  print("");
})();