import config from '@payload-config'
import crypto from 'crypto'
import 'dotenv/config'
import fs from 'fs/promises'
import path from 'path'
import { getPayload, type File, type Payload } from 'payload'

const root = process.cwd()
const spaDir = path.join(root, 'src/spa')
const publicDir = path.join(root, 'public')

const mediaExtensions = new Set([
  '.avif',
  '.gif',
  '.jpeg',
  '.jpg',
  '.mov',
  '.mp4',
  '.png',
  '.svg',
  '.webm',
  '.webp',
  '.zip',
])

const mimeByExt: Record<string, string> = {
  '.avif': 'image/avif',
  '.gif': 'image/gif',
  '.jpeg': 'image/jpeg',
  '.jpg': 'image/jpeg',
  '.mov': 'video/quicktime',
  '.mp4': 'video/mp4',
  '.png': 'image/png',
  '.svg': 'image/svg+xml',
  '.webm': 'video/webm',
  '.webp': 'image/webp',
  '.zip': 'application/zip',
}

async function walk(dir: string): Promise<string[]> {
  const entries = await fs.readdir(dir, { withFileTypes: true })
  const files = await Promise.all(
    entries.map((entry) => {
      const full = path.join(dir, entry.name)
      return entry.isDirectory() ? walk(full) : Promise.resolve([full])
    }),
  )
  return files.flat()
}

function isMediaSource(value: string) {
  try {
    const parsed = value.startsWith('http') ? new URL(value) : undefined
    const pathname = parsed?.pathname || value.split('?')[0]
    return mediaExtensions.has(path.extname(pathname).toLowerCase()) || value.includes('images.unsplash.com')
  } catch {
    return false
  }
}

async function findSpaSources() {
  const files = (await walk(spaDir)).filter((file) => /\.(tsx?|jsx?)$/.test(file))
  const sources = new Set<string>()
  const quotedUrl = /["'`]((?:https?:\/\/images\.unsplash\.com\/[^"'`\s)]+)|(?:\/(?:images\/)?[^"'`\s)]+\.(?:avif|gif|jpe?g|mov|mp4|png|svg|webm|webp|zip)(?:\?[^"'`\s)]*)?))["'`]/gi
  const cssUrl = /url\((['"]?)(.*?)\1\)/g

  for (const file of files) {
    const content = await fs.readFile(file, 'utf8')
    for (const match of content.matchAll(quotedUrl)) {
      if (isMediaSource(match[1])) sources.add(match[1])
    }
    for (const match of content.matchAll(cssUrl)) {
      if (isMediaSource(match[2])) sources.add(match[2])
    }
  }

  return sources
}

async function findPublicMedia() {
  const sources = new Set<string>()
  const files = await walk(publicDir)
  for (const file of files) {
    const relative = path.relative(publicDir, file).split(path.sep).join('/')
    if (relative.startsWith('media/')) continue

    const ext = path.extname(file).toLowerCase()
    if (!mediaExtensions.has(ext)) continue
    sources.add(`/${relative}`)
  }
  return sources
}

function safeRemoteName(url: string) {
  const parsed = new URL(url)
  const ext = path.extname(parsed.pathname) || '.jpg'
  const hash = crypto.createHash('sha1').update(url).digest('hex').slice(0, 10)
  return `${parsed.hostname.replace(/[^a-z0-9]+/gi, '-')}-${hash}${ext}`.toLowerCase()
}

async function fileForSource(source: string): Promise<File> {
  if (source.startsWith('http')) {
    const res = await fetch(source)
    if (!res.ok) throw new Error(`Failed to fetch ${source}: ${res.status}`)
    const data = Buffer.from(await res.arrayBuffer())
    const name = safeRemoteName(source)
    return {
      name,
      data,
      mimetype: res.headers.get('content-type')?.split(';')[0] || mimeByExt[path.extname(name)] || 'application/octet-stream',
      size: data.byteLength,
    }
  }

  const cleanSource = source.split('?')[0]
  const fullPath = path.join(publicDir, cleanSource.replace(/^\//, ''))
  const data = await fs.readFile(fullPath)
  const ext = path.extname(fullPath).toLowerCase()
  return {
    name: path.basename(fullPath),
    data,
    mimetype: mimeByExt[ext] || 'application/octet-stream',
    size: data.byteLength,
  }
}

function altForSource(source: string) {
  const basename = source.startsWith('http') ? safeRemoteName(source) : path.basename(source.split('?')[0])
  return basename.replace(/\.[^.]+$/, '').replace(/[-_]+/g, ' ')
}

async function findExistingMedia(payload: Payload, filename: string) {
  const existing = await payload.find({
    collection: 'media',
    depth: 0,
    limit: 1,
    where: { filename: { equals: filename } },
  })
  return existing.docs[0]
}

async function main() {
  const payload = await getPayload({ config })
  const sources = new Set([...(await findPublicMedia()), ...(await findSpaSources())])
  const sortedSources = [...sources].sort((a, b) => a.localeCompare(b))
  const assets: { source: string; media: number | string }[] = []

  payload.logger.info(`Migrating ${sortedSources.length} SPA media assets into Payload...`)

  for (const source of sortedSources) {
    const file = await fileForSource(source)
    let doc = await findExistingMedia(payload, file.name)

    if (!doc) {
      doc = await payload.create({
        collection: 'media',
        data: { alt: altForSource(source) },
        file,
      })
      payload.logger.info(`created media: ${source} -> ${doc.filename}`)
    } else {
      payload.logger.info(`reused media: ${source} -> ${doc.filename}`)
    }

    assets.push({ source, media: doc.id })
  }

  const bySource = new Map(assets.map((asset) => [asset.source, asset]))
  const assetId = (source: string) => bySource.get(source)?.media
  await Promise.all([
    assetId('/bmp-logo.png')
      ? payload.updateGlobal({
          slug: 'header',
          data: { logo: assetId('/bmp-logo.png') } as never,
          context: { disableRevalidate: true },
        })
      : Promise.resolve(),
    assetId('/bmp-logo.png')
      ? payload.updateGlobal({
          slug: 'footer',
          data: {
            logo: assetId('/bmp-logo.png'),
            partnerLogos: [
              { alt: 'EWIF – Europäisches Wirtschaftsforum', image: assetId('/images/ewif-logo.png') },
              {
                alt: 'Hochschule für angewandtes Management · Gipfeldialog Altaussee',
                image: assetId('/images/partner-logos.png'),
              },
            ].filter((item) => item.image),
          } as never,
          context: { disableRevalidate: true },
        })
      : Promise.resolve(),
    assetId('/munich-skyline.jpg')
      ? payload.updateGlobal({
          slug: 'site-settings',
          data: { skylineImage: assetId('/munich-skyline.jpg') } as never,
          context: { disableRevalidate: true },
        })
      : Promise.resolve(),
  ])

  payload.logger.info('SPA media migration complete.')
  process.exit(0)
}

main().catch((error) => {
  console.error(error)
  process.exit(1)
})