function isComfyBusyTimeout(error: unknown) {
  const err = error as { statusCode?: number; status?: number; data?: { code?: string }; message?: string; statusMessage?: string }
  if (err?.statusCode === 409 || err?.status === 409 || err?.data?.code === 'COMFY_BUSY') return true
  const text = `${err?.statusMessage || ''} ${err?.message || ''}`
  return text.includes('still busy after 3 minutes')
}

function parseDuration(raw: string) {
  const seconds = Number(raw)
  if (!Number.isFinite(seconds)) return 5
  return Math.min(120, Math.max(0.5, seconds))
}

const SAMPLERS = new Set(['res_multistep', 'euler', 'dpmpp_2m'])
const SCHEDULERS = new Set(['simple', 'ddim_uniform', 'sgm_uniform'])

function frameLength(seconds: number, fps: number) {
  return Math.max(5, Math.floor(seconds * fps))
}

function parseFps(raw: string | undefined) {
  const fps = Number(raw)
  return fps === 12 || fps === 30 || fps === 24 ? fps : 24
}

function parseCfg(raw: string | undefined, turbo: boolean) {
  const fallback = turbo ? 1.5 : 4
  const value = Number(raw)
  if (!Number.isFinite(value)) return fallback
  const snapped = Math.round(value * 2) / 2
  return Math.min(10, Math.max(1, snapped))
}

function parseSampler(raw: string | undefined) {
  return SAMPLERS.has(raw || '') ? raw! : 'res_multistep'
}

function parseScheduler(raw: string | undefined) {
  return SCHEDULERS.has(raw || '') ? raw! : 'simple'
}

export default defineEventHandler(async (event) => {
  const form = await readMultipartFormData(event)
  if (!form?.length) {
    throw createError({ statusCode: 400, statusMessage: 'Expected multipart form data' })
  }

  const fields: Record<string, string> = {}
  let image: { filename: string; data: Buffer; type?: string } | null = null
  for (const part of form) {
    if (part.name === 'image' && part.filename && part.data?.length) {
      image = { filename: part.filename, data: part.data, type: part.type }
    } else if (part.name && part.data) {
      fields[part.name] = part.data.toString('utf8')
    }
  }

  if (!image) {
    throw createError({ statusCode: 400, statusMessage: 'An initial image is required' })
  }
  const prompt = (fields.prompt || '').trim()
  if (!prompt) {
    throw createError({ statusCode: 400, statusMessage: 'A motion prompt is required' })
  }

  const { width, height } = resolveOutputSize(fields.aspect, image.data, Number(fields.width), Number(fields.height))
  const turbo = fields.turbo !== 'false'
  const steps = Number(fields.steps || (turbo ? 8 : 20))
  const seed = fields.seed && fields.seed !== 'random'
    ? Number(fields.seed)
    : Math.floor(Math.random() * 2_147_483_647)
  const durationSeconds = parseDuration(fields.duration || '5')
  const fps = parseFps(fields.fps)
  const cfg = parseCfg(fields.cfg, turbo)
  const samplerName = parseSampler(fields.sampler_name)
  const scheduler = parseScheduler(fields.scheduler)
  const length = frameLength(durationSeconds, fps)
  const hideThumbnail = fields.hideThumbnail === 'true'
  const hideInput = fields.hideInput === 'true'
  const sound = fields.sound !== 'false'
  const clipName = (fields.name || '').trim().slice(0, 80)
  const ownerKey = libraryOwnerKey(event)
  const library = publicLibrary(event)
  const folderId = library.folders.some(folder => folder.id === fields.folderId)
    ? fields.folderId
    : library.folders[0]?.id
  if (!folderId) {
    throw createError({ statusCode: 400, statusMessage: 'Create a library folder before generating' })
  }
  const destFolder = library.folders.find(folder => folder.id === folderId)
  const folderLocked = Boolean(destFolder?.protected && !destFolder.unlocked)
  assertFolderExists(event, folderId)
  const still = await saveStill({
    ownerKey,
    folderId,
    filename: image.filename,
    data: image.data,
    width,
    height,
    hideInput
  })

  const job = createJob()
  job.maxStep = steps
  job.hideThumbnail = hideThumbnail
  job.library = {
    ownerKey,
    folderId,
    hideThumbnail,
    hideInput,
    folderLocked,
    name: clipName,
    prompt,
    aspect: fields.aspect || 'auto',
    width,
    height,
    steps,
    turbo,
    seed,
    cfg,
    fps,
    samplerName,
    scheduler,
    thumb: image.data,
    stillId: still.id,
    stillFilename: still.filename,
    duration: durationSeconds,
    sound,
    draftId: (fields.draftId || '').trim() || undefined
  }
  emitJob(job, { type: 'status', message: 'Checking ComfyUI...', progress: 1 })

  void runGeneration(job, { prompt, image, width, height, steps, seed, turbo, length, sound, cfg, fps, samplerName, scheduler }).catch(async (error) => {
    if (isComfyBusyTimeout(error) && job.library) {
      try {
        const draft = await saveRetryDraft({
          ownerKey: job.library.ownerKey,
          id: job.library.draftId,
          folderId: job.library.folderId,
          stillId: job.library.stillId,
          stillFilename: job.library.stillFilename,
          name: job.library.name,
          prompt: job.library.prompt,
          aspect: job.library.aspect,
          width: job.library.width,
          height: job.library.height,
          steps: job.library.steps,
          turbo: job.library.turbo,
          seed: job.library.seed,
          duration: job.library.duration || durationSeconds,
          hideThumbnail: job.library.hideThumbnail,
          hideInput: job.library.hideInput === true,
          sound: job.library.sound !== false,
          cfg: job.library.cfg,
          fps: job.library.fps,
          samplerName: job.library.samplerName,
          scheduler: job.library.scheduler
        })
        job.library.draftId = draft.id
        job.status = 'deferred'
        const message = 'ComfyUI was still busy after 3 minutes. Saved this job — click it under Held jobs to restore the form.'
        emitJob(job, { type: 'deferred', draftId: draft.id, message, progress: job.progress })
        return
      } catch {
        // fall through to a normal error if the held job could not be saved
      }
    }
    const message = error instanceof Error ? error.message : String(error)
    job.status = 'error'
    job.error = message
    emitJob(job, { type: 'error', error: message, message })
  })

  return {
    jobId: job.id,
    clientId: job.clientId,
    seed,
    width,
    height,
    aspect: fields.aspect || 'auto',
    cfg,
    fps,
    sampler_name: samplerName,
    scheduler,
    steps,
    turbo,
    folderId,
    hideThumbnail,
    folderLocked
  }
})

async function runGeneration(
  job: ReturnType<typeof createJob>,
  params: {
    prompt: string
    image: { filename: string; data: Buffer; type?: string }
    width: number
    height: number
    steps: number
    seed: number
    turbo: boolean
    length: number
    sound: boolean
    cfg: number
    fps: number
    samplerName: string
    scheduler: string
  }
) {
  await ensureComfyReady((status) => {
    emitJob(job, {
      type: status.state === 'busy' ? 'busy' : 'status',
      message: status.message,
      progress: status.state === 'online' ? Math.max(job.progress, 3) : Math.max(job.progress, 1),
      busy: status.state === 'busy',
      queueRunning: status.queueRunning,
      queuePending: status.queuePending
    })
  })

  const done = watchComfyJob(job)
  job.status = 'uploading'
  emitJob(job, { type: 'status', message: 'Uploading image to ComfyUI...', progress: 4 })
  const uploaded = await uploadImage(params.image, job.id)
  if (job.library) {
    job.library.imageName = uploaded.name
    job.library.imageSubfolder = uploaded.subfolder
  }
  emitJob(job, { type: 'status', message: 'Queueing MiniMax H3 job...', progress: 6 })
  await waitForComfySocket(job, 4000)

  const graph = buildWorkflow({
    prompt: params.prompt,
    imageName: uploaded.name,
    width: params.width,
    height: params.height,
    steps: params.steps,
    seed: params.seed,
    turbo: params.turbo,
    length: params.length,
    cfg: params.cfg,
    fps: params.fps,
    samplerName: params.samplerName,
    scheduler: params.scheduler,
    filenamePrefix: comfyFilenamePrefix(),
    sound: params.sound
  })

  const queued = await queuePrompt(graph, job.clientId)
  job.promptId = queued.prompt_id
  job.status = 'running'
  if (job.library?.draftId) {
    await deleteRetryDraft(job.library.ownerKey, job.library.draftId).catch(() => null)
    job.library.draftId = undefined
  }
  if (job.library && job.promptId) {
    writePendingJob({
      jobId: job.id,
      promptId: job.promptId,
      clientId: job.clientId,
      ownerKey: job.library.ownerKey,
      folderId: job.library.folderId,
      hideThumbnail: job.library.hideThumbnail,
      folderLocked: job.library.folderLocked,
      name: job.library.name,
      prompt: job.library.prompt,
      aspect: job.library.aspect,
      width: job.library.width,
      height: job.library.height,
      steps: job.library.steps,
      turbo: job.library.turbo,
      seed: job.library.seed,
      startedAt: job.startedAt,
      imageName: job.library.imageName,
      imageSubfolder: job.library.imageSubfolder,
      extendTmpDir: job.library.extendTmpDir,
      extendPart1Path: job.library.extendPart1Path
    })
  }
  emitJob(job, { type: 'status', message: 'Job queued on ComfyUI', progress: 8 })
  await done
}