import { existsSync, mkdirSync, readdirSync, readFileSync, writeFileSync, renameSync, unlinkSync } from 'node:fs'
import { join } from 'node:path'
import { createJob, emitJob, getJob, restoreMusicJob, type Job } from './jobs'
import { saveTrack, findYue2Track } from './library'
import { sharedGpuHeaders } from './sharedGpu'
import type { MusicJobParams } from './musicChain'

function settings() {
  const config = useRuntimeConfig()
  return { url: String(config.comfyControlUrl || process.env.COMFY_CONTROL_URL || '').replace(/\/$/, ''),
    token: String(config.comfyControlToken || process.env.COMFY_CONTROL_TOKEN || '') }
}
export function yue2Configured() { return Boolean(settings().url) }
function pendingRoot() { return join(String(useRuntimeConfig().libraryDir || process.env.LIBRARY_DIR || '/data/library'), 'yue2-pending') }
export function yue2PendingAlive(jobId: string) {
  if (!jobId) return false
  return existsSync(join(pendingRoot(), `${jobId}.json`))
}
async function request(path: string, body?: unknown) {
  const { url, token } = settings()
  if (!url) throw new Error('YuE2 host is not configured. Set COMFY_CONTROL_URL.')
  const response = await fetch(`${url}/yue2/${path}`, {
    method: body === undefined ? 'GET' : 'POST',
    headers: { ...(token ? { Authorization: `Bearer ${token}` } : {}),
      ...(body === undefined ? {} : { ...sharedGpuHeaders(), 'Content-Type': 'application/json' }) },
    body: body === undefined ? undefined : JSON.stringify(body), signal: AbortSignal.timeout(60_000)
  })
  if (!response.ok) {
    const detail = await response.json().catch(() => ({})) as { message?: string; error?: string }
    throw Object.assign(new Error(detail.message || detail.error || `YuE2 host returned ${response.status}`), { statusCode: response.status })
  }
  return response
}
function persist(job: Job) {
  mkdirSync(pendingRoot(), { recursive: true })
  const path = join(pendingRoot(), `${job.id}.json`)
  writeFileSync(path + '.tmp', JSON.stringify({ id: job.id, clientId: job.clientId, startedAt: job.startedAt, library: job.library, trackId: job.trackId }))
  renameSync(path + '.tmp', path)
}
async function settle(job: Job) {
  const { onLiveVideoSettled } = await import('./studioQueue')
  await onLiveVideoSettled(job)
  const path = join(pendingRoot(), `${job.id}.json`)
  if (existsSync(path)) unlinkSync(path)
}
export async function cancelYue2Job(job: Job) {
  await request(`jobs/${job.id}/cancel`, {})
  job.status = 'cancelled'
  emitJob(job, { type: 'error', error: 'Cancelled', message: 'Cancelled' })
}

async function watch(job: Job) {
  let failures = 0
  while (job.status !== 'cancelled') {
    try {
      const state = await (await request(`jobs/${job.id}`)).json() as {
        status: string; message: string; error?: string; stage?: string; progress?: number; step?: number; maxStep?: number; duration?: number
      }
      if (job.status === 'cancelled') { await settle(job); return }
      job.musicActivity = { checkedAt: Date.now(), running: ['starting', 'running', 'cancelling'].includes(state.status) }
      if (state.status === 'error' || state.status === 'cancelled') {
        job.status = state.status === 'cancelled' ? 'cancelled' : 'error'
        job.error = state.error || state.message
        if (/out of memory/i.test(job.error || '')) job.error += ' YuE2 does not switch engines automatically.'
        emitJob(job, { type: 'error', error: job.error, message: job.error })
        await settle(job)
        return
      }
      if (state.status === 'complete') {
        job.saving = true
        emitJob(job, { type: 'status', message: 'Saving audio to library…', progress: 98 })
        const lib = job.library!
        lib.audioExt = 'wav'
        job.trackId ||= findYue2Track(lib.ownerKey, job.id)?.id
        if (!job.trackId) {
          const audio = Buffer.from(await (await request(`jobs/${job.id}/audio`)).arrayBuffer())
          const track = await saveTrack({ ownerKey: lib.ownerKey, folderId: lib.folderId, name: lib.name,
            tags: lib.tags || lib.prompt, lyrics: lib.lyrics || '', duration: state.duration || lib.duration || 60,
            seed: lib.seed, steps: 0, cfg: 0, instrumental: lib.instrumental === true,
            engine: 'yue2', audio, ext: 'wav', comfyFilename: `yue2-${job.id}.wav` })
          job.trackId = track.id
          persist(job)
        }
        job.status = 'complete'; job.saving = false
        emitJob(job, { type: 'complete', message: lib.folderLocked ? 'Saved to the locked folder.' : 'Track ready',
          progress: 100, trackId: job.trackId, folderLocked: lib.folderLocked, audioExt: 'wav' })
        await settle(job)
        return
      }
      failures = 0
      job.status = 'running'
      const percent = Number(state.progress || 0)
      emitJob(job, { type: 'progress', message: `${state.message}${state.maxStep ? ` · ${state.step}/${state.maxStep}` : ''}`,
        progress: Math.min(95, Math.max(1, percent)), step: state.step || 0, maxStep: state.maxStep || 0 })
    } catch (error) {
      failures++
      job.saving = false
      emitJob(job, { type: 'status', message: `YuE2 connection/save check failed; retrying: ${error instanceof Error ? error.message : String(error)}` })
      if (failures >= 10) {
        job.status = 'error'; job.error = 'YuE2 host unreachable or audio save failed. Job files are retained for recovery.'
        emitJob(job, { type: 'error', error: job.error, message: job.error })
        const { onLiveVideoSettled } = await import('./studioQueue')
        await onLiveVideoSettled(job)
        return
      }
    }
    await new Promise(resolve => setTimeout(resolve, 2000))
  }
  await settle(job)
}

export function startYue2Job(params: MusicJobParams) {
  const job = createJob('music')
  job.yue2 = true
  job.library = { ...params, prompt: params.tags, engine: 'yue2', aspect: 'audio', width: 0, height: 0,
    hideThumbnail: false, turbo: false, sound: true }
  persist(job)
  setTimeout(() => { void (async () => {
    try {
      if (job.status === 'cancelled') { await settle(job); return }
      await request('jobs', { id: job.id, tags: params.tags, lyrics: params.lyrics,
        duration: params.duration, seed: params.seed })
      await watch(job)
    } catch (error) {
      const statusCode = (error as { statusCode?: number })?.statusCode
      if (statusCode && statusCode >= 400 && statusCode < 500) {
        job.status = 'error'; job.error = error instanceof Error ? error.message : String(error)
        emitJob(job, { type: 'error', error: job.error, message: job.error })
        await settle(job)
        return
      }
      emitJob(job, { type: 'status', message: `Checking YuE2 submission: ${error instanceof Error ? error.message : String(error)}` })
      await watch(job)
    }
  })() }, 0)
  return job
}

export function resumeYue2Jobs() {
  if (!existsSync(pendingRoot())) return
  for (const file of readdirSync(pendingRoot()).filter(file => /^[a-zA-Z0-9-]+\.json$/.test(file))) {
    try {
      const record = JSON.parse(readFileSync(join(pendingRoot(), file), 'utf8'))
      if (getJob(record.id)) continue
      const job = restoreMusicJob(record)
      job.yueGp = false
      job.yue2 = true
      job.message = 'Reconnecting to YuE2'
      void watch(job)
    } catch { /* Preserve invalid records for diagnosis. */ }
  }
}