/*
<MODULE_CONTRACT>
<purpose>Maintains packages/share/src/semantic/jsonld/shared.ts as an authored share authored module so agents can evolve it without rediscovering local boundaries.</purpose>
<non-goals>
  <item>Do not modify node structure.</item>
</non-goals>
</MODULE_CONTRACT>
<CHANGE_SUMMARY>
  <item>RFC-1097: step 6 — compass.migrate codemod run

Mechanical v1 to v2 header migration across the workspace: 942 files rewritten — CHANGE_SUMMARY windows collapsed into history, forbidden v1 blocks stripped, KEY_DECISIONS seeded from @ai-invariant comments (5 files) or TODO placeholders (103 files), blocks reordered to canonical order.</item>
  <item>RFC-1097: sweep — werkstatt-engine clean

Sweep batch 4: 73 Compass headers on headerless engine files (certification, component-runtime, isolation, evolution, testing), real KEY_DECISIONS on 75 files (kernel, cache, dht, swim, gitmesh, runtime), ~80 purpose expansions (CONTRACT-02/PURPOSE-02), non-goals on 13 CONTRACT-03 files, CS-07 history literal fix repo-wide (253 files). Policy: .template.ts/.template.astro excludedPaths. werkstatt-engine now 0 diagnostics.</item>
</CHANGE_SUMMARY>
*/

import type { JsonLdNode } from "./types.ts";

export function dedupeGraph(nodes: JsonLdNode[]): JsonLdNode[] {
  const seenIds = new Set<string>();

  return nodes.filter((node) => {
    const nodeId = typeof node["@id"] === "string" ? node["@id"] : null;
    if (!nodeId) {
      return true;
    }

    if (seenIds.has(nodeId)) {
      return false;
    }

    seenIds.add(nodeId);
    return true;
  });
}