import { Buffer } from 'buffer'
import { scaffoldProducts, scaffoldAvailability } from '@/src/trpc/apis/common-apis/common'
import { scaffoldEssentialConsts } from '@/src/trpc/apis/common-apis/common-trpc-index'
import { scaffoldStores } from '@/src/trpc/apis/user-apis/apis/stores'
import { scaffoldSlotsWithProducts } from '@/src/trpc/apis/user-apis/apis/slots'
import { scaffoldBanners } from '@/src/trpc/apis/user-apis/apis/banners'
import { scaffoldStoreWithProducts } from '@/src/trpc/apis/user-apis/apis/stores'
import { getStoresSummary, incrementCacheVersion, incrementAvailabilityVersionNum, incrementSlotsVersionNum } from '@/src/dbService'
import { imageUploadS3 } from '@/src/lib/s3-client'
import { getApiCacheKey, getCloudflareApiToken, getCloudflareZoneId, getAssetsDomain } from '@/src/lib/env-exporter'
import { CACHE_FILENAMES } from '@packages/shared'
import { retryWithExponentialBackoff } from '@/src/lib/retry'

const buildCachePath = (path: string, version: number) => `v-${version}/${path}`

const buildAvailabilityPath = (version: number) => `av-${version}/${CACHE_FILENAMES.availability}`

const buildSlotsPath = (version: number) => `slots/v-${version}/${CACHE_FILENAMES.slots}`

function constructCacheUrl(path: string, version: number): string {
  return `${getAssetsDomain()}${getApiCacheKey()}/${buildCachePath(path, version)}`
}

function constructAvailabilityUrl(version: number): string {
  return `${getAssetsDomain()}${buildAvailabilityPath(version)}`
}

function constructSlotsUrl(version: number): string {
  return `${getAssetsDomain()}${buildSlotsPath(version)}`
}

export interface CreateAllCacheFilesResult {
  cacheVersion: number
  products: string
  essentialConsts: string
  stores: string
  slotsVersion: number
  availabilityVersion: number
  banners: string
  individualStores: string[]
}

export async function createAllCacheFiles(): Promise<CreateAllCacheFilesResult> {
  console.log('Starting creation of all cache files...')

  const cacheVersion = await incrementCacheVersion()

  // Create all global cache files in parallel
  const [
    productsKey,
    essentialConstsKey,
    storesKey,
    slotsVersion,
    availabilityVersion,
    bannersKey,
    individualStoreKeys,
  ] = await Promise.all([
    createProductsFileInternal(cacheVersion),
    createEssentialConstsFileInternal(cacheVersion),
    createStoresFileInternal(cacheVersion),
    createSlotsCacheFile(),
    createAvailabilityCacheFile(),
    createBannersFileInternal(cacheVersion),
    createAllStoresFilesInternal(cacheVersion),
  ])

  const stores = await getStoresSummary()

  // Collect all URLs for batch cache purge
  const urls = [
    constructCacheUrl(CACHE_FILENAMES.products, cacheVersion),
    constructCacheUrl(CACHE_FILENAMES.essentialConsts, cacheVersion),
    constructCacheUrl(CACHE_FILENAMES.stores, cacheVersion),
    constructSlotsUrl(slotsVersion),
    constructAvailabilityUrl(availabilityVersion),
    constructCacheUrl(CACHE_FILENAMES.banners, cacheVersion),
    ...stores.map((store) => constructCacheUrl(`stores/${store.id}.json`, cacheVersion)),
  ]

  // Purge all caches in one batch with retry
  try {
    await retryWithExponentialBackoff(() => clearUrlCache(urls))
    console.log(`Cache purged for all ${urls.length} files`)
  } catch (error) {
    console.error(`Failed to purge cache for all files after 3 retries`, error)
  }

  console.log('All cache files created successfully')

  return {
    cacheVersion,
    products: productsKey,
    essentialConsts: essentialConstsKey,
    stores: storesKey,
    slotsVersion,
    availabilityVersion,
    banners: bannersKey,
    individualStores: individualStoreKeys,
  }
}

// Internal versions that skip cache purging (for batch operations)
async function createProductsFileInternal(version: number): Promise<string> {
  const productsData = await scaffoldProducts()
  const jsonContent = JSON.stringify(productsData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  const filePath = `${getApiCacheKey()}/${buildCachePath(CACHE_FILENAMES.products, version)}`

  console.log(filePath)
  return await imageUploadS3(
    buffer,
    'application/json',
    filePath
      )

}

export async function createAvailabilityCacheFile(): Promise<number> {
  const version = await incrementAvailabilityVersionNum()
  const availabilityData = await scaffoldAvailability()
  const jsonContent = JSON.stringify(availabilityData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  const filePath = buildAvailabilityPath(version)

  console.log(filePath)
  await imageUploadS3(
    buffer,
    'application/json',
    filePath
  )

  return version
}

async function createEssentialConstsFileInternal(version: number): Promise<string> {
  const essentialConstsData = await scaffoldEssentialConsts()
  const jsonContent = JSON.stringify(essentialConstsData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  return await imageUploadS3(
    buffer,
    'application/json',
    `${getApiCacheKey()}/${buildCachePath(CACHE_FILENAMES.essentialConsts, version)}`
  )
}

async function createStoresFileInternal(version: number): Promise<string> {
  const storesData = await scaffoldStores()
  const jsonContent = JSON.stringify(storesData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  return await imageUploadS3(
    buffer,
    'application/json',
    `${getApiCacheKey()}/${buildCachePath(CACHE_FILENAMES.stores, version)}`
  )
}

export async function createSlotsCacheFile(): Promise<number> {
  const version = await incrementSlotsVersionNum()
  const slotsData = await scaffoldSlotsWithProducts()
  const jsonContent = JSON.stringify(slotsData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  const filePath = buildSlotsPath(version)

  console.log(filePath)
  await imageUploadS3(
    buffer,
    'application/json',
    filePath
  )

  return version
}

async function createBannersFileInternal(version: number): Promise<string> {
  const bannersData = await scaffoldBanners()
  const jsonContent = JSON.stringify(bannersData, null, 2)
  const buffer = Buffer.from(jsonContent, 'utf-8')
  return await imageUploadS3(
    buffer,
    'application/json',
    `${getApiCacheKey()}/${buildCachePath(CACHE_FILENAMES.banners, version)}`
  )
}

async function createAllStoresFilesInternal(version: number): Promise<string[]> {
  /*
  // Old implementation - direct DB queries:
  import { db } from '@/src/db/db_index'
  import { storeInfo } from '@/src/db/schema'

  const stores = await db.select({ id: storeInfo.id }).from(storeInfo)
  */

  const stores = await getStoresSummary()
  const results: string[] = []

  for (const store of stores) {
    const storeData = await scaffoldStoreWithProducts(store.id)
    const jsonContent = JSON.stringify(storeData, null, 2)
    const buffer = Buffer.from(jsonContent, 'utf-8')
    const s3Key = await imageUploadS3(
      buffer,
      'application/json',
      `${getApiCacheKey()}/${buildCachePath(`stores/${store.id}.json`, version)}`
    )
    results.push(s3Key)
  }

  console.log(`Created ${results.length} store cache files`)
  return results
}

export async function clearUrlCache(urls: string[]): Promise<{ success: boolean; errors?: string[] }> {
  const cloudflareApiToken = getCloudflareApiToken()
  const cloudflareZoneId = getCloudflareZoneId()
  if (!cloudflareApiToken || !cloudflareZoneId) {
    console.warn('Cloudflare credentials not configured, skipping cache clear')
    return { success: false, errors: ['Cloudflare credentials not configured'] }
  }

  try {
    const resp = await fetch(
      `https://api.cloudflare.com/client/v4/zones/${cloudflareZoneId}/purge_cache`,
      {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${cloudflareApiToken}`,
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ files: urls }),
      }
    )

    const result = await resp.json() as { success: boolean; errors?: { message: string }[] }

    if (!result.success) {
      const errorMessages = result.errors?.map(e => e.message) || ['Unknown error']
      console.error(`Cloudflare cache purge failed for URLs: ${urls.join(', ')}`, errorMessages)
      return { success: false, errors: errorMessages }
    }

    console.log(`Successfully purged ${urls.length} URLs from Cloudflare cache: ${urls.join(', ')}`)
    return { success: true }
  } catch (error) {
    console.log(error)
    const errorMessage = error instanceof Error ? error.message : 'Unknown error'
    console.error(`Error clearing Cloudflare cache for URLs: ${urls.join(', ')}`, errorMessage)
    return { success: false, errors: [errorMessage] }
  }
}

export async function clearAllCache(): Promise<{ success: boolean; errors?: string[] }> {
  const cloudflareApiToken = getCloudflareApiToken()
  const cloudflareZoneId = getCloudflareZoneId()
  if (!cloudflareApiToken || !cloudflareZoneId) {
    console.warn('Cloudflare credentials not configured, skipping cache clear')
    return { success: false, errors: ['Cloudflare credentials not configured'] }
  }

  try {
    const resp = await fetch(
      `https://api.cloudflare.com/client/v4/zones/${cloudflareZoneId}/purge_cache`,
      {
        method: 'POST',
        headers: {
          'Authorization': `Bearer ${cloudflareApiToken}`,
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ purge_everything: true }),
      }
    )

    const result = await resp.json() as { success: boolean; errors?: { message: string }[] }

    if (!result.success) {
      const errorMessages = result.errors?.map(e => e.message) || ['Unknown error']
      console.error('Cloudflare cache purge failed:', errorMessages)
      return { success: false, errors: errorMessages }
    }

    console.log('Successfully purged all cache from Cloudflare')
    return { success: true }
  } catch (error) {
    const errorMessage = error instanceof Error ? error.message : 'Unknown error'
    console.error('Error clearing Cloudflare cache:', errorMessage)
    return { success: false, errors: [errorMessage] }
  }
}