import { existsSync } from 'node:fs'
import type { Job, JobEvent } from '~/server/utils/jobs'
import { getJob, restoreJob } from '~/server/utils/jobs'
import type { PendingJob } from '~/server/utils/pending'
import { isLastChainShot, libraryFromPending, pendingFromJob, remainingAfterCurrentShot, writePendingJob, deletePendingJob } from '~/server/utils/pending'
import { syncQueueFromJob } from '~/server/utils/shotQueue'

function classifyError(message: string) {
  const lower = message.toLowerCase()
  if (lower.includes('out of memory') || (lower.includes('cuda') && lower.includes('alloc')) || lower.includes('vram')) {
    return 'ComfyUI VRAM allocation failed. Try Turbo or a smaller aspect ratio.'
  }
  if (lower.includes('econnrefused') || lower.includes('unreachable') || lower.includes('fetch failed')) {
    return 'ComfyUI host connection dropped. Confirm the desktop instance is running and reachable on the LAN.'
  }
  if (lower.includes('timeout')) {
    return 'Network timeout talking to ComfyUI. The job may still be running on the desktop.'
  }
  return message
}

function sleep(ms: number) {
  return new Promise(resolve => setTimeout(resolve, ms))
}

function chainMeta(job: Job) {
  const total = Math.max(1, job.library?.chainTotal || 1)
  const index = job.library?.chainIndex ?? 0
  return {
    total,
    index,
    step: index + 1,
    label: job.library?.chainLabel || (index === 0 ? 'Initial' : `Extension ${index}`),
    chained: total > 1
  }
}

export function mapChainProgress(job: Job, localPct: number) {
  const { total, index, chained } = chainMeta(job)
  const local = Math.max(0, Math.min(100, localPct))
  if (!chained) return Math.round(local)
  const share = 100 / total
  return Math.min(99, Math.round(index * share + (Math.min(local, 99) / 100) * share))
}

export function formatChainMessage(job: Job, message: string, samplePct?: number) {
  const { chained, step, total, label } = chainMeta(job)
  if (!chained) return message
  if (typeof samplePct === 'number') {
    return `Step ${step}/${total}: Generating ${label} (${samplePct}%)`
  }
  if (/waiting 3s buffer/i.test(message)) {
    return `Step ${step}/${total}: Waiting 3s buffer...`
  }
  return `Step ${step}/${total}: ${message}`
}

export function emitChainJob(job: Job, event: JobEvent, samplePct?: number) {
  const { chained, step, total, label } = chainMeta(job)
  const next: JobEvent = { ...event }
  if (next.message) {
    next.message = formatChainMessage(job, next.message, samplePct)
  }
  if (chained && typeof next.progress === 'number' && next.type !== 'complete' && next.type !== 'checkpoint') {
    next.overallProgress = mapChainProgress(job, next.progress)
  }
  if (chained) {
    next.chainStep = step
    next.chainTotal = total
    next.chainLabel = label
  }
  emitJob(job, next)
}

export function watchComfyJob(job: Job, options: { persist?: boolean } = {}): Promise<void> {
  const persist = options.persist !== false
  job.socketReady = false
  job.saving = false
  const ws = new WebSocket(comfyWsUrl(job.clientId))
  let settled = false
  let finishing = false
  let pollTimer: ReturnType<typeof setInterval> | null = null
  let timeout: ReturnType<typeof setTimeout> | null = null

  return new Promise((resolve) => {
    let localProgress = 0
    const startedAt = Date.now()
    let lastActivity = Date.now()
    const IDLE_MS = 30 * 60 * 1000
    const ABSOLUTE_MS = 3 * 60 * 60 * 1000

    const markActivity = () => {
      lastActivity = Date.now()
    }

    const emitLocal = (event: JobEvent, samplePct?: number) => {
      markActivity()
      if (typeof event.progress === 'number') localProgress = event.progress
      emitChainJob(job, event, samplePct)
    }

    const cleanup = () => {
      if (timeout) clearTimeout(timeout)
      if (pollTimer) clearInterval(pollTimer)
      timeout = null
      pollTimer = null
      try { ws.close() } catch { /* ignore */ }
    }

    const armIdle = () => {
      if (timeout) clearTimeout(timeout)
      if (settled) return
      const absLeft = ABSOLUTE_MS - (Date.now() - startedAt)
      if (absLeft <= 0) {
        void fail('Timed out waiting for ComfyUI (3 hours).')
        return
      }
      const idleLeft = IDLE_MS - (Date.now() - lastActivity)
      timeout = setTimeout(() => {
        if (settled || finishing) return
        if (Date.now() - lastActivity >= IDLE_MS) {
          void fail('Timed out waiting for ComfyUI progress (30 minutes with no updates). The desktop job may still be running.')
          return
        }
        armIdle()
      }, Math.max(1000, Math.min(idleLeft, absLeft)))
    }

    const fail = async (error: string) => {
      if (settled || finishing) return
      settled = true
      cleanup()
      job.status = job.status === 'cancelled' ? 'cancelled' : 'error'
      job.error = classifyError(error)
      emitChainJob(job, { type: 'error', error: job.error, message: job.error })
      await syncQueueFromJob(job).catch(() => null)
      if (job.id) deletePendingJob(job.id)
      removeExtendTemp(job.library?.extendTmpDir)
      await purgeComfyArtifacts({
        imageName: job.library?.imageName,
        imageSubfolder: job.library?.imageSubfolder,
        extraImageNames: job.library?.referenceImageNames
      })
      resolve()
    }

    const succeed = async () => {
      if (settled || finishing || !job.promptId) return false
      finishing = true
      job.saving = true
      try {
        const history = await fetchHistory(job.promptId)
        const video = extractVideo(history, job.promptId)
        if (!video) {
          finishing = false
          job.saving = false
          return false
        }
        if (settled) return false
        settled = true
        cleanup()
        try {
          job.video = video
          const stitching = Boolean(job.library?.extendPart1Path && job.library.extendTmpDir)
          emitLocal({
            type: 'status',
            message: stitching ? 'Extracting last frame & stitching extension...' : (persist ? 'Saving to library...' : 'Downloading segment...'),
            progress: stitching ? 97 : 98
          })
          if (job.library) {
            let buffer = await downloadComfyVideo(video)
            if (stitching) {
              if (!existsSync(job.library.extendPart1Path!)) {
                throw new Error('Extension source clip was missing during stitch')
              }
              buffer = await stitchExtension({
                part1Path: job.library.extendPart1Path!,
                part2: buffer,
                tmpDir: job.library.extendTmpDir!
              })
            }
            const clip = await saveClip({
              ownerKey: job.library.ownerKey,
              folderId: job.library.folderId,
              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,
              hideThumbnail: job.library.hideThumbnail,
              hideInput: job.library.hideInput,
              video: buffer,
              thumb: (job.library.parentClipId || (job.library.chainIndex || 0) > 0 || /last[\s._-]*frame/i.test(job.library.imageName || ''))
                ? undefined
                : job.library.thumb,
              comfyFilename: video.filename,
              cfg: job.library.cfg,
              fps: job.library.fps,
              samplerName: job.library.samplerName,
              scheduler: job.library.scheduler,
              familyId: job.library.familyId || (job.library.familyId = crypto.randomUUID()),
              parentClipId: job.library.parentClipId,
              chainIndex: job.library.chainIndex,
              workflow: job.library.workflow,
              stillId: job.library.stillId,
              sound: job.library.sound
            })
            job.clipId = clip.id
            job.savedPromptId = job.promptId
            job.hideThumbnail = clip.hideThumbnail
            job.library.thumb = undefined
            job.library.name = nextClipPartName(clip.name)
            job.library.parentClipId = clip.id
            await syncQueueFromJob(job, clip.id).catch(() => null)
            await purgeComfyArtifacts({
              video,
              imageName: job.library.imageName,
              imageSubfolder: job.library.imageSubfolder,
              extraImageNames: job.library.referenceImageNames,
              promptId: job.promptId
            })
            if (!persist) {
              job.segmentBuffer = buffer
              job.status = 'running'
              writePendingJob(pendingFromJob(job, {
                promptId: '',
                currentClipId: clip.id
              }))
              job.saving = false
              emitLocal({
                type: 'checkpoint',
                message: stitching ? 'Extension checkpoint saved' : 'Initial segment saved',
                progress: chainMeta(job).chained ? mapChainProgress(job, 99) : 99,
                clipId: clip.id,
                hideThumbnail: job.hideThumbnail,
                folderLocked: job.library.folderLocked
              })
              resolve()
              return true
            }
            removeExtendTemp(job.library.extendTmpDir)
            job.library.extendTmpDir = undefined
          }
          job.status = 'complete'
          const queuedRemaining = job.library ? remainingAfterCurrentShot(job.library).length : 0
          emitJob(job, {
            type: 'complete',
            message: job.library?.folderLocked
              ? 'Saved to the locked folder. Unlock it to view.'
              : queuedRemaining > 0
                ? `Shot ${chainMeta(job).step} of ${chainMeta(job).total} saved. ${queuedRemaining} remaining on Queue.`
                : (job.library?.extendSourceClipId || (job.library?.chainTotal || 1) > 1 ? 'Extended video ready' : 'Video ready'),
            progress: 100,
            filename: job.library?.folderLocked ? undefined : video.filename,
            subfolder: job.library?.folderLocked ? undefined : video.subfolder,
            mediaType: job.library?.folderLocked ? undefined : video.type,
            clipId: job.clipId,
            hideThumbnail: job.hideThumbnail,
            folderLocked: job.library?.folderLocked,
            chainStep: job.library?.chainStep,
            chainTotal: job.library?.chainTotal,
            chainLabel: job.library?.chainLabel,
            queuedRemaining,
            queueId: job.library?.queueId
          })
          deletePendingJob(job.id)
          job.saving = false
        } catch (saveError) {
          job.saving = false
          removeExtendTemp(job.library?.extendTmpDir)
          const message = saveError instanceof Error ? saveError.message : String(saveError)
          job.status = 'error'
          job.error = persist
            ? `Video generated but library save failed: ${message}`
            : `Segment finished but could not be prepared: ${message}`
          emitChainJob(job, { type: 'error', error: job.error, message: job.error })
        }
        resolve()
        return true
      } catch (error) {
        finishing = false
        job.saving = false
        throw error
      }
    }

    let dropMisses = 0

    const pollHistory = async () => {
      if (settled || finishing || !job.promptId) return
      try {
        const inspected = inspectHistory(await fetchHistory(job.promptId), job.promptId)
        if (inspected.error) {
          await fail(inspected.error)
          return
        }
        if (inspected.video) {
          await succeed()
          return
        }
        markActivity()
        if (await isComfyPromptDropped(job.promptId)) {
          dropMisses += 1
          if (dropMisses >= 20) {
            await fail('ComfyUI dropped this job. Reloading the Comfy interface clears the queue. Generate again.')
          }
        } else {
          dropMisses = 0
        }
      } catch {
        // Transient ComfyUI history misses are expected while the graph is still running.
      }
    }

    armIdle()

    pollTimer = setInterval(() => {
      void pollHistory()
    }, 2000)

    ws.addEventListener('open', () => {
      job.socketReady = true
      emitLocal({ type: 'status', message: 'Connected to ComfyUI', progress: Math.max(localProgress, 4) })
    })

    ws.addEventListener('close', () => {
      if (settled || finishing || !job.promptId) return
      void pollHistory()
    })

    ws.addEventListener('message', async (event) => {
      let payload: { type?: string; data?: Record<string, unknown> }
      try {
        payload = JSON.parse(String(event.data))
      } catch {
        return
      }
      const data = payload.data || {}
      if (job.promptId && data.prompt_id && data.prompt_id !== job.promptId) return

      if (payload.type === 'progress') {
        const value = Number(data.value || 0)
        const max = Number(data.max || 1)
        const pct = 12 + Math.round((value / Math.max(max, 1)) * 70)
        const samplePct = Math.round((value / Math.max(max, 1)) * 100)
        job.status = 'running'
        emitLocal({
          type: 'progress',
          step: value,
          maxStep: max,
          progress: pct,
          node: data.node ? String(data.node) : null,
          message: `Sampling step ${value}/${max} (${samplePct}%)`
        }, samplePct)
      }

      if (payload.type === 'executing') {
        const node = data.node === null || data.node === undefined ? null : String(data.node)
        if (node === null) {
          const saved = await succeed()
          if (!saved) {
            emitLocal({ type: 'status', message: 'Waiting for ComfyUI to save the MP4...', progress: 96 })
          }
          return
        }
        const label = NODE_LABELS[node] || `Running node ${node}`
        const encoding = isEncodingNode(node)
        emitLocal({
          type: 'executing',
          node,
          progress: encoding ? 90 : Math.max(localProgress, 10),
          message: encoding ? 'Encoding video...' : `${label}...`
        })
      }

      if (payload.type === 'execution_error') {
        const message = String(data.exception_message || data.message || 'ComfyUI node execution failed')
        await fail(message)
      }

      if (payload.type === 'execution_interrupted') {
        job.status = 'cancelled'
        await fail('Job interrupted.')
      }
    })
  })
}

export async function waitForComfySocket(job: Job, ms = 4000) {
  const started = Date.now()
  while (Date.now() - started < ms) {
    if (job.socketReady) return
    await sleep(100)
  }
}

const pendingWatches = new Set<string>()

export function ensurePendingWatch(pending: PendingJob) {
  const existing = getJob(pending.jobId)
  if (existing) return existing
  const lastShot = isLastChainShot(pending)
  const job = restoreJob({
    id: pending.jobId,
    clientId: pending.clientId,
    promptId: pending.promptId,
    startedAt: pending.startedAt,
    hideThumbnail: pending.hideThumbnail,
    library: libraryFromPending(pending)
  })
  if (pending.currentClipId) job.clipId = pending.currentClipId
  if (!pendingWatches.has(job.id)) {
    pendingWatches.add(job.id)
    const resume = async () => {
      try {
        if (pending.promptId) {
          await watchComfyJob(job, { persist: lastShot })
        }
        if (job.status === 'error' || job.status === 'cancelled' || job.status === 'complete') return
        if (!lastShot) {
          const { continueQueuedExtensionsIfNeeded } = await import('~/server/utils/videoChain')
          await continueQueuedExtensionsIfNeeded(job)
        }
      } catch (error) {
        const message = error instanceof Error ? error.message : String(error)
        if (job.status === 'error' || job.status === 'cancelled') return
        job.status = 'error'
        job.error = message
        emitChainJob(job, { type: 'error', error: message, message })
      } finally {
        pendingWatches.delete(job.id)
      }
    }
    void resume()
  }
  return job
}