import {
  allowSuperAdminFallback,
  getSuperAdminBases,
  isSuperAdminUrl,
  resolveTenantDomain,
  SA_RETRY_ROUNDS,
} from '@/config/superadmin'

type VersionResponse =
  | string
  | number
  | {
      version?: string | number
      data?: string | number | { version?: string | number; value?: string | number }
      value?: string | number
      user?: unknown
    }

const VERSION_SUCCESS_URL_KEY = 'VERSION_Success_URL'
export const VERSION_RETRY_ROUNDS = SA_RETRY_ROUNDS

let versionFetchPromise: Promise<string | null> | null = null

/** فقط SuperAdmin — بدون رجیستری قدیمی */
function getVersionUrls() {
  const domain = encodeURIComponent(resolveTenantDomain())
  return getSuperAdminBases().map((base) => `${base}/get_version?domain=${domain}`)
}

function sortVersionUrls(urls: string[]) {
  const lastSuccessUrl = localStorage.getItem(VERSION_SUCCESS_URL_KEY)
  if (!lastSuccessUrl || !urls.includes(lastSuccessUrl) || !isSuperAdminUrl(lastSuccessUrl)) {
    if (lastSuccessUrl && !isSuperAdminUrl(lastSuccessUrl)) {
      localStorage.removeItem(VERSION_SUCCESS_URL_KEY)
    }
    return [...urls]
  }
  return [lastSuccessUrl, ...urls.filter((url) => url !== lastSuccessUrl)]
}

function clearStaleVersionSuccessUrl(url: string) {
  if (localStorage.getItem(VERSION_SUCCESS_URL_KEY) === url) {
    localStorage.removeItem(VERSION_SUCCESS_URL_KEY)
  }
}

function readUserVersion(user: unknown) {
  if (!user || typeof user !== 'object' || Array.isArray(user)) {
    return ''
  }

  const record = user as { version?: string | number; value?: string | number }
  const version = record.version ?? record.value

  return version === undefined || version === null ? '' : String(version).trim()
}

function normalizeVersionResponse(response: VersionResponse) {
  if (typeof response === 'string' || typeof response === 'number') {
    return String(response).trim()
  }

  if (!response) return ''

  if (typeof response.data === 'string' || typeof response.data === 'number') {
    return String(response.data).trim()
  }

  const directVersion =
    response.version ??
    response.value ??
    (typeof response.data === 'object' ? response.data?.version ?? response.data?.value : undefined)

  if (directVersion !== undefined && directVersion !== null) {
    return String(directVersion).trim()
  }

  return readUserVersion(response.user)
}

async function fetchVersion(url: string, timeout = 3500): Promise<string | null> {
  const controller = new AbortController()
  const timeoutId = window.setTimeout(() => controller.abort(), timeout)

  try {
    const response = await fetch(url, {
      method: 'GET',
      headers: {
        Accept: 'application/json',
      },
      cache: 'no-store',
      signal: controller.signal,
    })

    if (!response.ok) {
      throw new Error(`Version request failed with status ${response.status}`)
    }

    const contentType = response.headers.get('content-type') ?? ''
    if (!contentType.includes('application/json')) {
      throw new Error('Version response is not JSON')
    }

    const data = (await response.json()) as VersionResponse

    const version = normalizeVersionResponse(data)

    if (!version) {
      throw new Error('Version response is empty')
    }

    localStorage.setItem(VERSION_SUCCESS_URL_KEY, url)
    return version
  } finally {
    window.clearTimeout(timeoutId)
  }
}

async function tryFetchVersionFromUrls(
  urls: string[],
  rounds: number,
): Promise<string | null> {
  if (!urls.length) return null

  for (let round = 1; round <= rounds; round++) {
    for (let index = 0; index < urls.length; index++) {
      const url = urls[index]
      const timeout = index === urls.length - 1 ? 6000 : 3500

      try {
        const version = await fetchVersion(url, timeout)
        if (version) {
          return version
        }
      } catch (error) {
        clearStaleVersionSuccessUrl(url)
        console.warn(`Version failed from ${url}. Round: ${round}`, error)
      }
    }
  }

  return null
}

async function fetchVersionWithRetry(rounds = VERSION_RETRY_ROUNDS): Promise<string | null> {
  const urls = sortVersionUrls(getVersionUrls())
  const saUrls = urls.filter(isSuperAdminUrl)
  const otherUrls = urls.filter((url) => !isSuperAdminUrl(url))

  const lists =
    saUrls.length > 0
      ? allowSuperAdminFallback()
        ? [saUrls, otherUrls]
        : [saUrls]
      : [urls]

  for (const list of lists) {
    const version = await tryFetchVersionFromUrls(list, rounds)
    if (version) return version
  }

  return null
}

export function resetVersionCheckCache() {
  versionFetchPromise = null
}

export async function loadRemoteAppVersion(options?: {
  rounds?: number
  force?: boolean
}): Promise<string | null> {
  const rounds = options?.rounds ?? VERSION_RETRY_ROUNDS
  const force = options?.force ?? false

  if (force) {
    resetVersionCheckCache()
  }

  if (versionFetchPromise) {
    return versionFetchPromise
  }

  versionFetchPromise = fetchVersionWithRetry(rounds).finally(() => {
    versionFetchPromise = null
  })

  return versionFetchPromise
}