import { comfyConfigured, comfyFetch, getComfyHost } from '~/server/utils/comfy'
import { getBeastImageHost, imageComfyFetch, sameImageHost } from '~/server/utils/imageComfy'
import {
  XAIGEN_LORA_MESSAGE,
  MINIMAX_TURBO_LORA,
  filterLorasForStudio,
  imageLoraEngineMismatchMessage,
  imageLoraEngineOf,
  isXaigenOnlyLora,
  loraIdentityKey,
  normalizeLoraName,
  normalizeLoraStack,
  persistLoraFields,
  resolveComfyLoraName,
  type LoraKind,
  type LoraStackItem
} from '~/utils/loras'
import { isXaigenStudio, LTX_DISTILLED_LORA } from '~/utils/videoModels'

type WorkflowNode = { class_type: string; inputs: Record<string, unknown>; _meta?: { title?: string } }
type WorkflowGraph = Record<string, WorkflowNode>

const LORA_LOADER = 'LoraLoader'
const LORA_MODEL_ONLY = 'LoraLoaderModelOnly'
const OBJECT_INFO_NODES = [
  LORA_LOADER,
  LORA_MODEL_ONLY,
  'Power Lora Loader (rgthree)',
  'Lora Loader Stack (rgthree)',
  'LoraLoaderModelOnly [10]',
  'WanVideoLoraSelect',
  'LoraLoaderStacked'
]
const MODEL_FEED_CLASSES = new Set(['BasicGuider', 'CFGGuider', 'KSampler', 'KSamplerAdvanced'])
const CACHE_MS = 20_000
const SYSTEM_LORA_PREFERRED = [MINIMAX_TURBO_LORA, LTX_DISTILLED_LORA]

type LoraCache = {
  at: number
  image: string[]
  video: string[]
}

let cache: LoraCache | null = null
let inflight: Promise<LoraCache> | null = null
let inflightFresh = false
let loadSeq = 0

function uniqueNames(values: unknown[]) {
  const seen = new Set<string>()
  const out: string[] = []
  for (const value of values) {
    const name = String(value || '').trim()
    if (!name || seen.has(name)) continue
    seen.add(name)
    out.push(name)
  }
  return out
}

function comboFromSpec(spec: unknown): string[] {
  if (!Array.isArray(spec)) return []
  const first = spec[0]
  if (Array.isArray(first)) return first.filter((item): item is string => typeof item === 'string' && item.trim().length > 0)
  if (typeof first === 'string' && first.trim()) return spec.filter((item): item is string => typeof item === 'string' && item.trim().length > 0)
  return []
}

function namesFromObjectInfoNode(info: unknown) {
  if (!info || typeof info !== 'object') return [] as string[]
  const input = (info as { input?: { required?: Record<string, unknown>; optional?: Record<string, unknown> } }).input
  const buckets = [input?.required, input?.optional]
  const names: string[] = []
  for (const bucket of buckets) {
    if (!bucket) continue
    for (const [key, spec] of Object.entries(bucket)) {
      if (!/lora/i.test(key)) continue
      names.push(...comboFromSpec(spec))
    }
  }
  return uniqueNames(names)
}

async function fetchJson(path: string, via: 'video' | 'image', timeoutMs = 8000) {
  const res = via === 'image'
    ? await imageComfyFetch(path, { signal: AbortSignal.timeout(timeoutMs) })
    : await comfyFetch(path, { signal: AbortSignal.timeout(timeoutMs) })
  if (!res.ok) return null
  return res.json().catch(() => null)
}

function collectObjectInfoLoras(all: Record<string, unknown>) {
  const image: string[] = []
  const video: string[] = []
  let any = false
  for (const node of OBJECT_INFO_NODES) {
    const info = all[node]
    if (!info || typeof info !== 'object') continue
    const names = namesFromObjectInfoNode(info)
    if (!names.length) continue
    any = true
    if (node === LORA_LOADER) image.push(...names)
    else video.push(...names)
    if (node !== LORA_LOADER && node !== LORA_MODEL_ONLY) {
      image.push(...names)
      video.push(...names)
    }
  }
  if (any) return { image: uniqueNames(image), video: uniqueNames(video) }

  const imageAll: string[] = []
  const videoAll: string[] = []
  for (const [classType, info] of Object.entries(all)) {
    if (!/lora/i.test(classType)) continue
    const names = namesFromObjectInfoNode(info)
    if (classType === LORA_LOADER) imageAll.push(...names)
    else videoAll.push(...names)
  }
  return { image: uniqueNames(imageAll), video: uniqueNames(videoAll) }
}

async function fetchModelsLoras(via: 'video' | 'image') {
  const payload = await fetchJson('/models/loras', via)
  if (Array.isArray(payload)) return uniqueNames(payload)
  if (payload && typeof payload === 'object' && Array.isArray((payload as { loras?: unknown[] }).loras)) {
    return uniqueNames((payload as { loras: unknown[] }).loras)
  }
  return [] as string[]
}

async function fetchObjectInfoLoras(via: 'video' | 'image', fresh = false) {
  // Full /object_info is Comfy's model-list refresh (UI Refresh) and lists LoraLoader / model-only / rgthree / WanVideoLoraSelect.
  if (fresh) {
    const all = await fetchJson('/object_info', via, 45_000)
    if (all && typeof all === 'object') return collectObjectInfoLoras(all as Record<string, unknown>)
    return { image: [] as string[], video: [] as string[] }
  }

  const image: string[] = []
  const video: string[] = []
  let any = false
  for (const node of OBJECT_INFO_NODES) {
    const info = await fetchJson(`/object_info/${encodeURIComponent(node)}`, via)
    if (!info || typeof info !== 'object') continue
    const record = info as Record<string, unknown>
    const body = record[node] || (Object.keys(record).length === 1 ? record[Object.keys(record)[0] as string] : record)
    const names = namesFromObjectInfoNode(body)
    if (!names.length) continue
    any = true
    if (node === LORA_LOADER) image.push(...names)
    else video.push(...names)
    if (node !== LORA_LOADER && node !== LORA_MODEL_ONLY) {
      image.push(...names)
      video.push(...names)
    }
  }
  if (any) {
    return { image: uniqueNames(image), video: uniqueNames(video) }
  }

  const all = await fetchJson('/object_info', via, 45_000)
  if (!all || typeof all !== 'object') return { image: [] as string[], video: [] as string[] }
  return collectObjectInfoLoras(all as Record<string, unknown>)
}

async function discoverFromHost(via: 'video' | 'image', fresh = false) {
  const fromInfo = await fetchObjectInfoLoras(via, fresh).catch(() => ({ image: [] as string[], video: [] as string[] }))
  const models = await fetchModelsLoras(via).catch(() => [] as string[])
  const image = uniqueNames([...fromInfo.image, ...models])
  const video = uniqueNames([...fromInfo.video, ...models])
  if (!image.length && video.length) return { image: video, video }
  if (!video.length && image.length) return { image, video: image }
  return { image, video }
}

async function loadLoraCache(options: { fresh?: boolean } = {}): Promise<LoraCache> {
  const fresh = options.fresh === true
  const now = Date.now()
  if (!fresh && cache && now - cache.at < CACHE_MS) return cache
  // Fresh must not reuse a non-fresh inflight (stale list / frozen CACHE_MS window).
  if (inflight && (!fresh || inflightFresh)) return inflight
  const seq = ++loadSeq
  inflightFresh = fresh
  inflight = (async () => {
    const videoHost = comfyConfigured() ? getComfyHost() : ''
    const imageHost = getBeastImageHost()
    const same = Boolean(videoHost && imageHost && sameImageHost(videoHost, imageHost))
    const video = videoHost
      ? await discoverFromHost('video', fresh).catch(() => ({ image: [] as string[], video: [] as string[] }))
      : { image: [] as string[], video: [] as string[] }
    const image = imageHost && !same
      ? await discoverFromHost('image', fresh).catch(() => ({ image: [] as string[], video: [] as string[] }))
      : video
    const next: LoraCache = {
      at: Date.now(),
      image: uniqueNames([...image.image, ...video.image]),
      video: uniqueNames([...video.video, ...image.video])
    }
    // Comfy asleep / unreachable returns empty. Keep the last good list so the picker
    // does not vanish — but do NOT refresh `at`, or a blip freezes new folder drops out.
    // Never merge a shorter live list into the old one: deletes must disappear; adds must appear.
    if (!next.image.length && !next.video.length && cache && (cache.image.length || cache.video.length)) {
      return cache
    }
    // Superseded non-fresh must not overwrite a newer fresh result.
    if (seq !== loadSeq) return cache || next
    cache = next
    return next
  })().finally(() => {
    if (seq === loadSeq) {
      inflight = null
      inflightFresh = false
    }
  })
  return inflight
}

export async function listStudioLoras(options: { fresh?: boolean } = {}) {
  const xaigen = isXaigenStudio()
  try {
    const listed = await loadLoraCache(options)
    return {
      at: listed.at,
      image: filterLorasForStudio(listed.image, xaigen),
      video: filterLorasForStudio(listed.video, xaigen)
    }
  } catch {
    if (cache) {
      return {
        at: cache.at,
        image: filterLorasForStudio(cache.image, xaigen),
        video: filterLorasForStudio(cache.video, xaigen)
      }
    }
    return { at: 0, image: [] as string[], video: [] as string[] }
  }
}

/** Unfiltered Comfy filenames for graph system LoRAs (MiniMax turbo, LTX distilled). Reuses the listing cache. */
export function cachedComfyLoraNames(kind?: LoraKind) {
  if (!cache) return [] as string[]
  if (kind === 'image') return uniqueNames([...cache.image, ...cache.video])
  if (kind === 'video') return uniqueNames([...cache.video, ...cache.image])
  return uniqueNames([...cache.image, ...cache.video])
}

export async function ensureComfyLoraNames(kind?: LoraKind) {
  try {
    await loadLoraCache()
  } catch {
    /* keep whatever was cached */
  }
  return cachedComfyLoraNames(kind)
}

export function resolveGraphLoraNames(graph: WorkflowGraph, kind?: LoraKind) {
  const names = cachedComfyLoraNames(kind)
  for (const node of Object.values(graph)) {
    if (node.class_type !== LORA_LOADER && node.class_type !== LORA_MODEL_ONLY) continue
    const current = String(node.inputs.lora_name || '').trim()
    if (!current) continue
    const preferred = SYSTEM_LORA_PREFERRED.find(item => loraIdentityKey(item) === loraIdentityKey(current)) || current
    node.inputs.lora_name = names.length ? resolveComfyLoraName(preferred, names) : preferred
  }
}

function allowedLoraNames(kind?: LoraKind) {
  return filterLorasForStudio(cachedComfyLoraNames(kind), isXaigenStudio())
}

function resolveUserLoraName(name: string, kind?: LoraKind) {
  const allowed = allowedLoraNames(kind)
  if (!allowed.length) return name
  return resolveComfyLoraName(name, allowed)
}

export function assertLoraAllowed(raw: unknown, kind: LoraKind) {
  const name = normalizeLoraName(raw)
  if (!name) return ''
  if (isXaigenOnlyLora(name) && !isXaigenStudio()) {
    throw createError({ statusCode: 400, statusMessage: XAIGEN_LORA_MESSAGE })
  }
  const allowed = allowedLoraNames(kind)
  if (allowed.length) {
    const identity = loraIdentityKey(name)
    const listed = allowed.some((item) => {
      const path = item.replace(/\\/g, '/')
      return path === name || path.toLowerCase() === name.toLowerCase() || loraIdentityKey(item) === identity
    })
    if (!listed) {
      throw createError({ statusCode: 400, statusMessage: `Unknown ${kind} LoRA` })
    }
    return resolveUserLoraName(name, kind)
  }
  return name
}

export function parsePostedLora(raw: unknown, kind: LoraKind) {
  return parsePostedLoraStack(raw, kind)[0]?.name || ''
}

export function parsePostedLoraStack(raw: unknown, kind: LoraKind): LoraStackItem[] {
  const out: LoraStackItem[] = []
  for (const item of normalizeLoraStack(raw)) {
    const name = assertLoraAllowed(item.name, kind)
    if (!name) continue
    out.push({ ...item, name })
  }
  return out
}

export function parseShotLoras(raw: unknown, shotCount: number, kind: LoraKind = 'video') {
  return parseShotLoraStacks(raw, shotCount, kind).map(stack => stack[0]?.name || '')
}

export function parseShotLoraStacks(raw: unknown, shotCount: number, kind: LoraKind = 'video'): LoraStackItem[][] {
  const empty = Array.from({ length: shotCount }, () => [] as LoraStackItem[])
  if (!raw) return empty
  let parsed: unknown = raw
  if (typeof raw === 'string') {
    try {
      parsed = JSON.parse(raw)
    } catch {
      return empty
    }
  }
  if (!Array.isArray(parsed)) return empty
  return Array.from({ length: shotCount }, (_, index) => parsePostedLoraStack(parsed[index], kind))
}

export { persistLoraFields }

function linkSource(value: unknown): string | null {
  return Array.isArray(value) && typeof value[0] === 'string' ? value[0] : null
}

function alreadyHasLora(graph: WorkflowGraph, name: string) {
  const wanted = loraIdentityKey(name)
  if (!wanted) return false
  return Object.values(graph).some((node) => {
    if (node.class_type !== LORA_LOADER && node.class_type !== LORA_MODEL_ONLY) return false
    return loraIdentityKey(String(node.inputs.lora_name || '')) === wanted
  })
}

function injectAfter(
  graph: WorkflowGraph,
  sourceId: string,
  nodeId: string,
  node: WorkflowNode
) {
  if (!graph[sourceId] || graph[nodeId]) return
  graph[nodeId] = node
  for (const [id, other] of Object.entries(graph)) {
    if (id === nodeId) continue
    for (const [key, value] of Object.entries(other.inputs)) {
      const src = linkSource(value)
      if (src === sourceId && Array.isArray(value)) {
        other.inputs[key] = [nodeId, value[1]]
      }
    }
  }
}

function findModelFeed(graph: WorkflowGraph) {
  for (const node of Object.values(graph)) {
    if (!MODEL_FEED_CLASSES.has(node.class_type)) continue
    const source = linkSource(node.inputs.model)
    if (source && graph[source]) return source
  }
  return ''
}

function bypassLoraNode(graph: WorkflowGraph, id: string) {
  const node = graph[id]
  if (!node) return
  const model = Array.isArray(node.inputs.model) ? node.inputs.model : null
  const clip = Array.isArray(node.inputs.clip) ? node.inputs.clip : null
  for (const [otherId, other] of Object.entries(graph)) {
    if (otherId === id) continue
    for (const [key, value] of Object.entries(other.inputs)) {
      const src = linkSource(value)
      if (src !== id || !Array.isArray(value)) continue
      const slot = value[1]
      if (slot === 0 && model) other.inputs[key] = [model[0], model[1]]
      else if (slot === 1 && clip) other.inputs[key] = [clip[0], clip[1]]
    }
  }
  delete graph[id]
}

/** Optional Klein-style LoraLoader: user stack only. Empty stack bypasses model/CLIP around the loader. */
export function applyOptionalLoraLoaders(graph: WorkflowGraph, stack?: unknown, kind: LoraKind = 'image') {
  const loaders = Object.entries(graph).filter(([, node]) => node.class_type === LORA_LOADER)
  const xaigen = isXaigenStudio()
  const items = normalizeLoraStack(stack)
    .filter(item => xaigen || !isXaigenOnlyLora(item.name))
    .map(item => ({
      ...item,
      name: resolveUserLoraName(item.name, kind)
    }))
    .filter(item => item.name && (xaigen || !isXaigenOnlyLora(item.name)))
  if (!loaders.length) {
    applyUserLoraToGraph(graph, items)
    return
  }
  if (!items.length) {
    for (const [id] of loaders) bypassLoraNode(graph, id)
    return
  }
  for (const [id] of loaders) {
    const first = items[0]
    graph[id].inputs.lora_name = first.name
    graph[id].inputs.strength_model = first.strengthModel
    graph[id].inputs.strength_clip = first.strengthClip
    graph[id]._meta = { title: items.length === 1 ? 'User LoRA' : 'User LoRA 1' }
    let sourceId = id
    for (const [index, item] of items.slice(1).entries()) {
      const nodeId = `user:lora:${id}:${index + 1}`
      injectAfter(graph, sourceId, nodeId, {
        class_type: LORA_LOADER,
        inputs: {
          lora_name: item.name,
          strength_model: item.strengthModel,
          strength_clip: item.strengthClip,
          model: [sourceId, 0],
          clip: [sourceId, 1]
        },
        _meta: { title: `User LoRA ${index + 2}` }
      })
      sourceId = nodeId
    }
  }
}

function linkRef(value: unknown): [string, number] | null {
  return Array.isArray(value) && typeof value[0] === 'string' && Number.isFinite(Number(value[1]))
    ? [value[0], Number(value[1])]
    : null
}

export function assertImageV2LoraStack(stack: unknown, engine: 'flux' | 'krea') {
  const items = normalizeLoraStack(stack)
  const wrong = items.find((item) => {
    const tagged = imageLoraEngineOf(item.name)
    return tagged != null && tagged !== engine
  })
  if (wrong) {
    throw createError({ statusCode: 400, statusMessage: imageLoraEngineMismatchMessage(wrong.name, engine) })
  }
  return items
}

function stripExistingLoraLoaders(graph: WorkflowGraph) {
  const remaining = new Set(
    Object.entries(graph)
      .filter(([, node]) => node.class_type === LORA_LOADER)
      .map(([id]) => id)
  )
  while (remaining.size) {
    const id = [...remaining].find(candidate => (
      ![...remaining].some(other => other !== candidate && linkSource(graph[other]?.inputs.model) === candidate)
    )) || [...remaining][0]
    bypassLoraNode(graph, id)
    remaining.delete(id)
  }
}

function modelConsumers(graph: WorkflowGraph) {
  return Object.values(graph).filter(node => MODEL_FEED_CLASSES.has(node.class_type) && linkRef(node.inputs.model))
}

function clipConsumers(graph: WorkflowGraph) {
  return Object.values(graph).filter(node => node.class_type === 'CLIPTextEncode' && linkRef(node.inputs.clip))
}

/**
 * Replace any template LoRA loaders with the posted chain, in list order.
 * Strength 0 skips that card (off). Empty chain leaves UNET/CLIP wired straight to the sampler.
 */
export function applyImageV2UserLoras(
  graph: WorkflowGraph,
  stack?: unknown,
  engine: 'flux' | 'krea' = 'flux'
) {
  stripExistingLoraLoaders(graph)

  const xaigen = isXaigenStudio()
  const items = normalizeLoraStack(stack)
    .filter(item => xaigen || !isXaigenOnlyLora(item.name))
    .map(item => ({
      ...item,
      name: resolveUserLoraName(item.name, 'image')
    }))
    .filter(item => item.name && (xaigen || !isXaigenOnlyLora(item.name)) && (item.strengthModel !== 0 || item.strengthClip !== 0))

  const wrong = items.find((item) => {
    const tagged = imageLoraEngineOf(item.name)
    return tagged != null && tagged !== engine
  })
  if (wrong) {
    throw createError({ statusCode: 400, statusMessage: imageLoraEngineMismatchMessage(wrong.name, engine) })
  }

  const guiders = modelConsumers(graph)
  const encodes = clipConsumers(graph)
  const modelFrom = linkRef(guiders[0]?.inputs.model) || (graph['4'] ? ['4', 0] as [string, number] : null)
  const clipFrom = linkRef(encodes[0]?.inputs.clip) || (graph['5'] ? ['5', 0] as [string, number] : null)
  if (!modelFrom || !clipFrom) {
    throw createError({ statusCode: 500, statusMessage: 'v2 graph has no model/CLIP feed for user LoRAs.' })
  }
  if (!items.length) return [] as LoraStackItem[]
  if (!guiders.length || !encodes.length) {
    throw createError({
      statusCode: 500,
      statusMessage: 'Image v2 LoRA chain is not connected to the sampler. Refusing to run without those adapters.'
    })
  }

  let model: [string, number] = modelFrom
  let clip: [string, number] = clipFrom
  const ids: string[] = []
  for (const [index, item] of items.entries()) {
    const nodeId = String(70 + index)
    if (graph[nodeId]) {
      throw createError({ statusCode: 500, statusMessage: `v2 graph already has node ${nodeId}. Refusing to overwrite it with a LoRA.` })
    }
    graph[nodeId] = {
      class_type: LORA_LOADER,
      inputs: {
        lora_name: item.name,
        strength_model: item.strengthModel,
        strength_clip: item.strengthClip,
        model,
        clip
      },
      _meta: { title: items.length === 1 ? 'LoRA' : `LoRA ${index + 1}` }
    }
    ids.push(nodeId)
    model = [nodeId, 0]
    clip = [nodeId, 1]
  }
  for (const node of guiders) node.inputs.model = model
  for (const node of encodes) node.inputs.clip = clip

  const hooked = guiders.every(node => linkRef(node.inputs.model)?.[0] === ids[ids.length - 1])
    && encodes.every(node => linkRef(node.inputs.clip)?.[0] === ids[ids.length - 1])
  if (!hooked) {
    throw createError({
      statusCode: 500,
      statusMessage: 'Image v2 LoRA chain is not connected to the sampler. Refusing to run without those adapters.'
    })
  }
  return items
}

export function applyUserLoraToGraph(graph: WorkflowGraph, stack?: unknown) {
  const xaigen = isXaigenStudio()
  const items = normalizeLoraStack(stack)
    .filter(item => xaigen || !isXaigenOnlyLora(item.name))
    .map(item => ({ ...item, name: resolveUserLoraName(item.name) }))
    .filter(item => item.name && (xaigen || !isXaigenOnlyLora(item.name)) && !alreadyHasLora(graph, item.name))
  if (!items.length) return

  const clipLoaders = Object.entries(graph).filter(([, node]) => node.class_type === LORA_LOADER)
  if (clipLoaders.length) {
    for (const [id] of clipLoaders) {
      let sourceId = id
      for (const [index, item] of items.entries()) {
        const nodeId = `user:lora:${id}:${index}`
        injectAfter(graph, sourceId, nodeId, {
          class_type: LORA_LOADER,
          inputs: {
            lora_name: item.name,
            strength_model: item.strengthModel,
            strength_clip: item.strengthClip,
            model: [sourceId, 0],
            clip: [sourceId, 1]
          },
          _meta: { title: items.length === 1 ? 'User LoRA' : `User LoRA ${index + 1}` }
        })
        sourceId = nodeId
      }
    }
    return
  }

  let source = findModelFeed(graph)
  if (!source) return
  for (const [index, item] of items.entries()) {
    const nodeId = index === 0 ? 'user:lora' : `user:lora:${index}`
    injectAfter(graph, source, nodeId, {
      class_type: LORA_MODEL_ONLY,
      inputs: {
        lora_name: item.name,
        strength_model: item.strengthModel,
        model: [source, 0]
      },
      _meta: { title: items.length === 1 ? 'User LoRA' : `User LoRA ${index + 1}` }
    })
    source = nodeId
  }
}