import assert from "node:assert/strict";
import crypto from "node:crypto";
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
const outputPath = path.join(root, "tests/golden/corrective/rehydration/M12-manifest-sha-drift.json");
const sha256 = (file) => crypto.createHash("sha256").update(fs.readFileSync(file)).digest("hex");
const relative = (file) => path.relative(root, file).replaceAll(path.sep, "/");
const write = process.argv.includes("--write");

const entries = [];
for (const task of fs.readdirSync(path.join(root, "tests/golden")).filter((name) => /^M12-/u.test(name)).sort()) {
  const manifestPath = path.join(root, "tests/golden", task, "manifest.json");
  if (!fs.existsSync(manifestPath)) continue;
  const manifest = JSON.parse(fs.readFileSync(manifestPath, "utf8"));
  for (const [artifact, binding] of Object.entries(manifest.artifacts ?? {})) {
    if (!binding?.path || !binding.sha256) continue;
    const artifactPath = path.join(root, binding.path);
    if (!fs.existsSync(artifactPath)) continue;
    const observedSha256 = sha256(artifactPath);
    if (observedSha256 !== binding.sha256) {
      entries.push({
        task,
        artifact,
        path: binding.path,
        originalSha256: binding.sha256,
        observedSha256,
        provenanceState: "BLOCKED_SOURCE_LOST",
      });
    }
  }
}

const evidence = {
  schemaVersion: 1,
  operation: "M12_LEGACY_MANIFEST_DRIFT_REHYDRATION",
  historicalEvidencePreserved: true,
  immutableSourceSnapshotAvailable: false,
  provenanceState: "BLOCKED_SOURCE_LOST",
  entries,
};

if (write) {
  fs.mkdirSync(path.dirname(outputPath), { recursive: true });
  fs.writeFileSync(outputPath, `${JSON.stringify(evidence, null, 2)}\n`);
} else {
  assert.ok(fs.existsSync(outputPath), "M12 drift evidence is missing; run with --write");
  const recorded = JSON.parse(fs.readFileSync(outputPath, "utf8"));
  assert.deepEqual(recorded, evidence, "M12 drift evidence is stale or current artifacts changed");
}

process.stdout.write(`m12-manifest-drift-ok entries=${entries.length} paths=${new Set(entries.map((entry) => entry.path)).size} provenance=${evidence.provenanceState} write=${write}\n`);