import test from 'brittle'
import fs from 'fs'
import os from 'os'
import path from 'path'
import {
  bareOsQvacModelsGuestPath,
  bareOsQvacModelsHostPath,
  bareOsQvacModelsStripHashPrefix,
  bareOsQvacHostGgufMatchesSize,
  bareOsQvacPrepareHostCacheConfig,
  bareOsQvacMaterializeGgufToHost,
  bareOsQvacMirrorHostGgufToHdms,
  bareOsQvacListHdmsGgufs,
  bareOsQvacFindHdmsGguf,
  BARE_OS_QVAC_MODELS_GUEST_ROOT
} from './lib/bare-os-qvac-models-store.mjs'

test('guest/host path + hash prefix mapping', async (t) => {
  t.is(
    bareOsQvacModelsGuestPath('5b8aae816570a09d_Qwen3-0.6B-Q4_0.gguf'),
    BARE_OS_QVAC_MODELS_GUEST_ROOT + '/5b8aae816570a09d_Qwen3-0.6B-Q4_0.gguf'
  )
  t.is(
    bareOsQvacModelsStripHashPrefix('5b8aae816570a09d_Qwen3-0.6B-Q4_0.gguf'),
    'Qwen3-0.6B-Q4_0.gguf'
  )
  t.is(
    bareOsQvacModelsStripHashPrefix('Qwen3-0.6B-Q4_0.gguf'),
    'Qwen3-0.6B-Q4_0.gguf'
  )
  const host = bareOsQvacModelsHostPath('a.gguf', '/tmp/qvac-cache')
  t.is(host, path.join('/tmp/qvac-cache', 'a.gguf'))
})

test('skip materialize when host size matches', async (t) => {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'bare-os-qvac-models-'))
  const hostPath = path.join(dir, 'model.gguf')
  const payload = Buffer.from('GGUF-fake-payload-0123456789')
  fs.writeFileSync(hostPath, payload)
  t.ok(bareOsQvacHostGgufMatchesSize(hostPath, payload.byteLength))
  t.absent(bareOsQvacHostGgufMatchesSize(hostPath, payload.byteLength + 1))

  /** @type {Record<string, Buffer>} */
  const files = {
    [BARE_OS_QVAC_MODELS_GUEST_ROOT + '/model.gguf']: payload
  }
  const vfs = {
    async stat(p) {
      const b = files[p]
      if (!b) throw new Error('ENOENT')
      return { size: b.byteLength }
    },
    async readFile(p) {
      const b = files[p]
      if (!b) throw new Error('ENOENT')
      return b
    },
    async writeFile() {
      throw new Error('should not write')
    },
    async readdir() {
      return ['model.gguf']
    }
  }

  const r = await bareOsQvacMaterializeGgufToHost({
    vfs,
    guestPath: BARE_OS_QVAC_MODELS_GUEST_ROOT + '/model.gguf',
    hostPath,
    guestSize: payload.byteLength
  })
  t.ok(r.ok)
  t.ok(r.skipped)
  t.is(r.reason, 'size_match')

  fs.rmSync(dir, { recursive: true, force: true })
})

test('materialize + mirror round-trip via fake vfs', async (t) => {
  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'bare-os-qvac-models-'))
  const hostPath = path.join(dir, 'hash_demo.gguf')
  const payload = Buffer.from('GGUF-roundtrip-bytes')
  /** @type {Record<string, Buffer>} */
  const files = {
    [BARE_OS_QVAC_MODELS_GUEST_ROOT + '/hash_demo.gguf']: payload
  }
  const vfs = {
    async stat(p) {
      const b = files[p]
      if (!b) throw new Error('ENOENT')
      return { size: b.byteLength }
    },
    async readFile(p) {
      const b = files[p]
      if (!b) throw new Error('ENOENT')
      return b
    },
    async writeFile(p, buf) {
      files[p] = Buffer.from(buf)
    },
    async readdir() {
      return Object.keys(files).map((p) => path.basename(p))
    }
  }

  const mat = await bareOsQvacMaterializeGgufToHost({
    vfs,
    guestPath: BARE_OS_QVAC_MODELS_GUEST_ROOT + '/hash_demo.gguf',
    hostPath
  })
  t.ok(mat.ok)
  t.absent(mat.skipped)
  t.is(fs.readFileSync(hostPath).equals(payload), true)

  // Change host and mirror back
  const next = Buffer.from('GGUF-roundtrip-bytes-UPDATED')
  fs.writeFileSync(hostPath, next)
  const mir = await bareOsQvacMirrorHostGgufToHdms({
    vfs,
    hostPath,
    guestName: 'hash_demo.gguf'
  })
  t.ok(mir.ok)
  t.absent(mir.skipped)
  t.ok(
    files[BARE_OS_QVAC_MODELS_GUEST_ROOT + '/hash_demo.gguf'].equals(next)
  )

  const names = await bareOsQvacListHdmsGgufs(vfs)
  t.ok(names.includes('hash_demo.gguf'))
  const found = await bareOsQvacFindHdmsGguf(vfs, 'hash_demo.gguf')
  t.is(found, BARE_OS_QVAC_MODELS_GUEST_ROOT + '/hash_demo.gguf')

  fs.rmSync(dir, { recursive: true, force: true })
})

test('prepareHostCacheConfig writes absolute cacheDirectory', async (t) => {
  const prev = process.env.BARE_OS_HOST_DATA
  const prevCfg = process.env.QVAC_CONFIG_PATH
  const prevRequire = globalThis.require
  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'bare-os-host-data-'))
  process.env.BARE_OS_HOST_DATA = root
  try {
    delete globalThis.require
    const cacheDir = path.join(root, 'qvac', 'models')
    const prepared = bareOsQvacPrepareHostCacheConfig({ cacheDir })
    t.is(prepared.cacheDir, cacheDir)
    t.ok(fs.existsSync(prepared.configPath))
    const body = JSON.parse(fs.readFileSync(prepared.configPath, 'utf8'))
    t.is(body.cacheDirectory, cacheDir)
    t.is(body.loggerLevel, 'error')
    t.is(body.loggerConsoleOutput, true)
    t.is(process.env.QVAC_CONFIG_PATH, prepared.configPath)
    t.is(typeof globalThis.require, 'function')
    const viaRequire = globalThis.require(prepared.configPath)
    t.is(viaRequire.cacheDirectory, cacheDir)
  } finally {
    if (prevRequire === undefined) delete globalThis.require
    else globalThis.require = prevRequire
    if (prev === undefined) delete process.env.BARE_OS_HOST_DATA
    else process.env.BARE_OS_HOST_DATA = prev
    if (prevCfg === undefined) delete process.env.QVAC_CONFIG_PATH
    else process.env.QVAC_CONFIG_PATH = prevCfg
    fs.rmSync(root, { recursive: true, force: true })
  }
})