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 indexPath = path.join(root, "tests/golden/M15-03A/task-index.json");
const index = JSON.parse(fs.readFileSync(indexPath, "utf8"));
const sha256File = (file) => crypto.createHash("sha256").update(fs.readFileSync(file)).digest("hex");
const resolve = (value) => path.join(root, value);
const planPath = resolve(index.source.path);
const catalogPath = resolve(index.catalog.path);
assert.equal(index.schemaVersion, 1);
assert.equal(sha256File(planPath), index.source.sha256, "task index source plan is stale; regenerate it");
assert.equal(sha256File(catalogPath), index.catalog.sha256, "task catalog hash mismatch");
assert.equal(Object.keys(index.entries).length, index.taskCount);

const catalog = fs.openSync(catalogPath, "r");
let activeCount = 0;
try {
  const bytes = fs.statSync(catalogPath).size;
  let previousEnd = 0;
  for (const [id, entry] of Object.entries(index.entries)) {
    assert.equal(entry.offset, previousEnd, `${id} offset is not contiguous`);
    assert.ok(entry.length > 0, `${id} has an empty record`);
    assert.ok(entry.offset + entry.length <= bytes, `${id} points past catalog`);
    const buffer = Buffer.alloc(entry.length);
    fs.readSync(catalog, buffer, 0, entry.length, entry.offset);
    const record = JSON.parse(buffer.toString("utf8"));
    assert.equal(record.id, id);
    assert.ok(record.gapId && record.ownerFamily && record.targetImplementationClass);
    if (record.state === "active") activeCount += 1;
    previousEnd += entry.length;
  }
  assert.equal(previousEnd, bytes, "catalog has unindexed bytes");
} finally {
  fs.closeSync(catalog);
}
assert.ok(index.entries[index.activeTask]?.previous, "active task must have a parent");
assert.equal(activeCount, 1, "task index must contain exactly one active task");
process.stdout.write(`task-index-ok tasks=${index.taskCount} active=${index.activeTask} catalog=${index.catalog.path}\n`);