/**
 * @module tests/integration/reserved-root-mint
 * @description THE RESERVED-ROOT MINT EXEMPTION (the release's final fix):
 * existing brains mint the VFS root (the all-zeros UUID) as int 0 by
 * construction at genesis — the one legitimate zero in the id space. The
 * adoption path must accept it (every real depot brain refused adoption
 * over this); a zero mint for ANY OTHER id remains a corrupt-mint refusal.
 */
import { describe, it, expect, afterEach } from 'vitest'
import { mkdtempSync, rmSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { Brainy } from '../../src/index.js'
import { NounType } from '../../src/types/graphTypes.js'

const ROOT = '00000000-0000-0000-0000-000000000000'
const dirs: string[] = []
const brains: Brainy[] = []
afterEach(async () => {
  for (const b of brains.splice(0)) await b.close().catch(() => {})
  for (const d of dirs.splice(0)) rmSync(d, { recursive: true, force: true })
})

type MapperBox = {
  metadataIndex: {
    getIdMapper(): {
      uuidToInt: Map<string, number>
      intToUuid: Map<number, string>
      dirty?: boolean
    }
  }
}

describe('reserved-root mint exemption', () => {
  it('adoption succeeds on a brain whose VFS root carries int 0 (the depot-brain shape)', async () => {
    const dir = mkdtempSync(join(tmpdir(), 'brainy-root0-'))
    dirs.push(dir)
    // Build the brain in 'defer' so we control the adoption moment.
    const brain = new Brainy({
      storage: { type: 'filesystem', path: dir },
      requireSubtype: false,
      logAuthority: 'defer'
    })
    await brain.init()
    brains.push(brain)
    await brain.add({ data: 'depot row', type: NounType.Document, metadata: { k: 1 } })

    // The genesis-era shape: the root's mint is 0 (white-box — real depot
    // brains carry this in their persisted mapper).
    const mapper = (brain as unknown as MapperBox).metadataIndex.getIdMapper()
    const currentInt = mapper.uuidToInt.get(ROOT)
    if (currentInt !== undefined) mapper.intToUuid.delete(currentInt)
    mapper.uuidToInt.set(ROOT, 0)
    mapper.intToUuid.set(0, ROOT)

    // THE PIN: adoption goes green — the backfill re-commits the root with
    // its legitimate int 0 instead of refusing the whole brain.
    const report = await brain.adoptLogAuthority()
    expect(report.verdict).toBe('green')
    expect(brain.logAuthority().authority).toBe('log')
    // And the brain keeps serving + writing after the flip.
    const fresh = await brain.add({ data: 'post-adopt', type: NounType.Document, metadata: { k: 2 } })
    expect((await brain.get(fresh))!.data).toContain('post-adopt')
  }, 120000)

  it('a zero mint for a NON-root id still refuses at the mint seam, loudly and typed', async () => {
    const dir = mkdtempSync(join(tmpdir(), 'brainy-nonroot0-'))
    dirs.push(dir)
    const brain = new Brainy({
      storage: { type: 'filesystem', path: dir },
      requireSubtype: false,
      logAuthority: 'defer'
    })
    await brain.init()
    brains.push(brain)
    const victim = await brain.add({ data: 'poisoned mint target', type: NounType.Document, metadata: {} })

    // Corrupt shape: some OTHER id maps to 0. (A full update() SELF-HEALS
    // this — the index cycle re-mints before the fact is written, which is
    // the correct outcome — so the pin holds the guard at its real seam:
    // the fact log's minter, which is what stands between a surviving zero
    // and the wire.)
    const mapper = (brain as unknown as MapperBox).metadataIndex.getIdMapper()
    const currentInt = mapper.uuidToInt.get(victim)
    if (currentInt !== undefined) mapper.intToUuid.delete(currentInt)
    mapper.uuidToInt.set(victim, 0)
    mapper.intToUuid.set(0, victim)

    const factLog = (brain as unknown as {
      generationStore: { getFactLog(): { intMinter(kind: string, id: string): bigint } }
    }).generationStore.getFactLog()
    expect(() => factLog.intMinter('noun', victim)).toThrow(
      /reserved for the VFS root|minted ints are positive/
    )
    // And the reserved root itself passes the same seam with 0.
    mapper.uuidToInt.set(ROOT, 0)
    mapper.intToUuid.set(0, ROOT)
    expect(factLog.intMinter('noun', ROOT)).toBe(0n)
  }, 120000)
})