// Makes the repository knotless-serve's archive tests read: a few dozen
// records, the MST made by @atproto/repo, as atproto's reference makes it,
// written as a CAR and as STAR-lite version 0 (microcosm's, as hubble
// serves it), with the DID and the key that signed its commit.
//
//   node harness/star-fixture.mjs crates/knotless-serve/fixtures
//
// STAR-lite: `*l\0`, the MST root's CID (36 bytes), the commit without its
// `data` (a varint length, then DRISL), then each record in key order as a
// varint key length, the key, a varint record length and the record.
// https://tangled.org/microcosm.blue/star/tree/main/v0-star/star-lite

import { writeFileSync } from 'node:fs'
import { join } from 'node:path'
import { encode } from '@atproto/lex-cbor'
import { Secp256k1Keypair } from '@atproto/crypto'
import { MemoryBlockstore, Repo, WriteOpAction, blocksToCarFile } from '@atproto/repo'

const out = process.argv[2]
if (!out) throw new Error('usage: node harness/star-fixture.mjs <dir>')

// A fixed key, so the fixture's DID stays the same each time it is made.
const keypair = await Secp256k1Keypair.import(
  '9085d2bef69286a6cbb51623c8fa258629945cd55ca705cc4e66700396894e0c',
)
const did = 'did:plc:archivefixture00000000000'
const writes = []
for (let i = 0; i < 30; i++) {
  const rkey = `3l${String(i).padStart(11, 'a')}`
  writes.push({
    action: WriteOpAction.Create,
    collection: 'dev.knotless.repo',
    rkey,
    record: {
      $type: 'dev.knotless.repo',
      name: `r${i}`,
      key: `k${i}`,
      createdAt: '2026-11-01T00:00:00.000Z',
    },
  })
  writes.push({
    action: WriteOpAction.Create,
    collection: 'app.bsky.feed.post',
    rkey,
    record: {
      $type: 'app.bsky.feed.post',
      text: `post ${i}`,
      createdAt: '2026-11-01T00:00:00.000Z',
    },
  })
}
const storage = new MemoryBlockstore()
const repo = await Repo.create(storage, did, keypair, writes)

const car = await blocksToCarFile(repo.cid, storage.blocks)

const varint = (n) => {
  const bytes = []
  while (n >= 0x80) {
    bytes.push((n & 0x7f) | 0x80)
    n >>>= 7
  }
  bytes.push(n)
  return Buffer.from(bytes)
}
const { data, ...partial } = repo.commit
const commit = Buffer.from(encode(partial))
const parts = [
  Buffer.from([0x2a, 0x6c, 0x00]),
  Buffer.from(data.bytes),
  varint(commit.length),
  commit,
]
for (const leaf of await repo.data.list()) {
  const record = Buffer.from(await storage.getBytes(leaf.value))
  const key = Buffer.from(leaf.key, 'ascii')
  parts.push(varint(key.length), key, varint(record.length), record)
}
const star = Buffer.concat(parts)

writeFileSync(join(out, 'repo.car'), car)
writeFileSync(join(out, 'repo.star'), star)
writeFileSync(
  join(out, 'repo.json'),
  `${JSON.stringify({ did, key: keypair.did(), rev: repo.commit.rev, records: writes.length }, null, 2)}\n`,
)
console.log(`${writes.length} records, CAR ${car.length} bytes, STAR-lite ${star.length} bytes`)