import { FastifyPluginAsync } from 'fastify'
import { createWriteStream, mkdirSync, unlink } from 'fs'
import { join, extname, basename } from 'path'
import { randomUUID } from 'crypto'
import { pipeline } from 'stream/promises'

const UPLOADS_DIR = process.env.UPLOADS_DIR ?? join(process.cwd(), 'uploads')
const CDN_HOST    = process.env.CDN_HOST ?? 'cdn.hotelsync.ru'

const ALLOWED_FOLDERS = ['categories', 'rooms', 'hotels', 'guests', 'tasks', 'chat'] as const
type UploadFolder = typeof ALLOWED_FOLDERS[number]

const ALLOWED_TYPES = ['image/jpeg', 'image/png', 'image/webp', 'image/gif']
const MAX_SIZE = 10 * 1024 * 1024 // 10MB

// Ensure base uploads directory exists
mkdirSync(UPLOADS_DIR, { recursive: true })

const upload: FastifyPluginAsync = async (fastify) => {
  // POST /api/upload?folder=categories — upload a single image, returns { url }
  fastify.post(
    '/api/upload',
    { onRequest: [fastify.authenticate] },
    async (request, reply) => {
      const { folder } = request.query as { folder?: string }
      const dir: UploadFolder = ALLOWED_FOLDERS.includes(folder as UploadFolder)
        ? (folder as UploadFolder)
        : 'rooms'

      const data = await request.file({ limits: { fileSize: MAX_SIZE } })
      if (!data) return reply.code(400).send({ error: 'No file provided' })

      if (!ALLOWED_TYPES.includes(data.mimetype)) {
        return reply.code(400).send({ error: 'Only images allowed (jpg, png, webp, gif)' })
      }

      const subDir = join(UPLOADS_DIR, dir)
      mkdirSync(subDir, { recursive: true })

      const ext      = extname(data.filename) || '.jpg'
      const filename = `${randomUUID()}${ext}`
      const filepath = join(subDir, filename)

      await pipeline(data.file, createWriteStream(filepath))

      return { url: `https://${CDN_HOST}/${dir}/${filename}` }
    },
  )

  // DELETE /api/upload?url=https://cdn.hotelsync.ru/categories/uuid.jpg
  fastify.delete(
    '/api/upload',
    { onRequest: [fastify.authenticate] },
    async (request, reply) => {
      const { url } = request.query as { url?: string }
      if (!url) return reply.code(400).send({ error: 'url is required' })

      // Extract path after CDN host: /categories/uuid.jpg → categories/uuid.jpg
      let relPath: string
      try {
        const parsed = new URL(url)
        // pathname is like /categories/uuid.jpg — strip leading slash
        relPath = parsed.pathname.replace(/^\//, '')
      } catch {
        return reply.code(400).send({ error: 'Invalid url' })
      }

      // Security: ensure path stays within UPLOADS_DIR (no ../.. traversal)
      const filepath = join(UPLOADS_DIR, relPath)
      if (!filepath.startsWith(UPLOADS_DIR + '/') && filepath !== UPLOADS_DIR) {
        return reply.code(400).send({ error: 'Invalid path' })
      }

      // Only allow known folders
      const folder = relPath.split('/')[0]
      if (!ALLOWED_FOLDERS.includes(folder as UploadFolder)) {
        return reply.code(400).send({ error: 'Invalid folder' })
      }

      // Only allow uuid-like filenames to prevent abuse
      const file = basename(relPath)
      if (!/^[0-9a-f-]{36}\.[a-z]+$/.test(file)) {
        return reply.code(400).send({ error: 'Invalid filename' })
      }

      await new Promise<void>((resolve, reject) =>
        unlink(filepath, err => err ? reject(err) : resolve())
      )

      return { ok: true }
    },
  )
}

export default upload