import { readFileSync, readdirSync } from 'node:fs'
import { fileURLToPath } from 'node:url'
import { dirname, join } from 'node:path'
import { describe, expect, it } from 'vitest'
import { createClientHandshake, createHostHandshake } from '../src/handshake.js'
import { nobleEd25519Signer, nobleEd25519Verifier } from '../src/ed25519.js'
import { createE2ESession } from '../src/session.js'
import { MemoryDevicePinStore } from '../src/keystore.js'
import { MAX_FRAME_BYTES } from '../src/envelope.js'
import { boundProofProvider, fromUtf8, makeHostIdentity, utf8, verifyBoundProof } from './helpers.js'

const HERE = dirname(fileURLToPath(import.meta.url))
const SRC = join(HERE, '..', 'src')

/** A passthrough "relay" that records every byte payload it forwards (the INV2 spy). */
class RelaySpy {
  readonly captured: Uint8Array[] = []
  forward(payload: Uint8Array): Uint8Array {
    expect(payload.length).toBeLessThanOrEqual(MAX_FRAME_BYTES) // §4.1 payloadLen guard
    this.captured.push(payload.slice())
    return payload
  }
  snapshot(): string {
    return this.captured.map((b) => Buffer.from(b).toString('latin1')).join(' ')
  }
}

async function establish() {
  const id = makeHostIdentity()
  const client = createClientHandshake({
    aeadOffer: ['xchacha20-poly1305', 'aes-256-gcm'],
    deviceAuthProofProvider: boundProofProvider(),
    verifier: nobleEd25519Verifier(),
    pinStore: new MemoryDevicePinStore(),
    hostId: 'h1',
  })
  const host = createHostHandshake({
    signer: nobleEd25519Signer(id.privateKey),
    agentPubkey: id.agentPubkey,
    supported: ['xchacha20-poly1305', 'aes-256-gcm'],
    verifyDeviceProof: async (p, b) => verifyBoundProof(p, b),
  })
  const spy = new RelaySpy()
  const ch = await client.start()
  const hh = await host.onClientHello(ch) // relay forwards these as opaque DATA
  const rc = await client.onHostHello(hh, id.agentPubkey)
  return {
    spy,
    clientSession: createE2ESession('client', rc),
    hostSession: createE2ESession('host', host.result!),
  }
}

describe('T12 integration + INV2 tripwire', () => {
  it('full loop through the relay spy: bidirectional plaintext round-trips', async () => {
    const { spy, clientSession, hostSession } = await establish()
    const up = spy.forward(clientSession.seal(utf8('echo test')))
    expect(fromUtf8(hostSession.open(up))).toBe('echo test')
    const down = spy.forward(hostSession.seal(utf8('echo reply')))
    expect(fromUtf8(clientSession.open(down))).toBe('echo reply')
  })

  it('INV2 tripwire (merge-blocking): the plaintext canary appears NOWHERE in the relay spy', async () => {
    const { spy, clientSession, hostSession } = await establish()
    const canary = `E2E_PLAINTEXT_CANARY_${crypto.randomUUID()}`
    const wire = spy.forward(clientSession.seal(utf8(canary)))
    expect(fromUtf8(hostSession.open(wire))).toBe(canary)
    // The marker must not transit in cleartext anywhere the relay can see.
    expect(spy.snapshot()).not.toContain(canary)
    for (const buf of spy.captured) {
      expect(Buffer.from(buf).toString('latin1')).not.toContain(canary)
      expect(Buffer.from(buf).toString('utf8')).not.toContain(canary)
    }
  })

  it('INV11-adjacent isolation: src imports no ws/pg/xterm/DOM-runtime/node builtins', () => {
    const forbidden = /from\s+['"](ws|pg|xterm|jsdom|node:[a-z]+|@xterm)/
    for (const file of readdirSync(SRC).filter((f) => f.endsWith('.ts'))) {
      const text = readFileSync(join(SRC, file), 'utf8')
      expect(text, `${file} must stay a pure isomorphic crypto core`).not.toMatch(forbidden)
    }
  })

  it('no console.* in src (coding-style)', () => {
    for (const file of readdirSync(SRC).filter((f) => f.endsWith('.ts'))) {
      expect(readFileSync(join(SRC, file), 'utf8')).not.toMatch(/console\.\w+/)
    }
  })

  it('vector freeze: all vector files parse to their expected shape (agent↔browser parity anchor)', () => {
    const dir = join(HERE, 'vectors')
    const files = readdirSync(dir).filter((f) => f.endsWith('.json'))
    expect(files.sort()).toEqual(['aead.json', 'envelope.json', 'fingerprint.json', 'hkdf.json'])
    const aead = JSON.parse(readFileSync(join(dir, 'aead.json'), 'utf8')) as unknown[]
    expect(aead.length).toBe(2)
    const fpr = JSON.parse(readFileSync(join(dir, 'fingerprint.json'), 'utf8')) as { enrollFpr: string }
    expect(fpr.enrollFpr.startsWith('sha256:')).toBe(true)
  })
})