import { Router } from 'express'
import fs from 'node:fs'
import { config } from './config.js'
import { db, blobPath } from './db.js'
import { newBlobId } from './ids.js'
import { checkDeviceToken } from './auth.js'
import { insertBlobRecord } from './blobs.js'

export const router = Router()

interface BlobRow {
  id: string
  kind: 'clip' | 'shot'
  content_type: string
  size_bytes: number
  created_at: number
  expires_at: number
}

router.post('/blobs', (req, res) => {
  if (!checkDeviceToken(req)) {
    res.status(401).json({ error: 'bad device token' })
    return
  }

  const kind = req.get('X-Blob-Kind')
  if (kind !== 'clip' && kind !== 'shot') {
    res.status(400).json({ error: 'X-Blob-Kind must be "clip" or "shot"' })
    return
  }

  const contentLength = Number(req.get('Content-Length') ?? 0)
  if (contentLength > config.maxUploadBytes) {
    res.status(413).json({ error: 'blob too large' })
    return
  }

  const id = newBlobId()
  const dest = blobPath(id)
  const writeStream = fs.createWriteStream(dest, { flags: 'wx' })

  let bytesReceived = 0
  req.on('data', (chunk: Buffer) => {
    bytesReceived += chunk.length
    if (bytesReceived > config.maxUploadBytes) {
      req.destroy()
      writeStream.destroy()
      fs.rm(dest, { force: true }, () => {})
    }
  })

  req.pipe(writeStream)

  writeStream.on('finish', () => {
    insertBlobRecord(id, kind, req.get('Content-Type') ?? 'application/octet-stream', bytesReceived)
    res.json({ id, url: kind === 'shot' ? `/s/${id}` : null })
  })

  writeStream.on('error', () => {
    fs.rm(dest, { force: true }, () => {})
    if (!res.headersSent) res.status(500).json({ error: 'write failed' })
  })
})

// Latest non-expired clip, for the pull side of clipboard sync — no
// history, no listing, just "what's the newest thing I copied elsewhere."
router.get('/clip/latest', (req, res) => {
  if (!checkDeviceToken(req)) {
    res.status(401).json({ error: 'bad device token' })
    return
  }

  const now = Math.floor(Date.now() / 1000)
  const row = db
    .prepare(
      `SELECT * FROM blobs WHERE kind = 'clip' AND expires_at > ? ORDER BY created_at DESC LIMIT 1`,
    )
    .get(now) as BlobRow | undefined

  if (!row) {
    res.status(204).end()
    return
  }

  res.set('Content-Type', row.content_type)
  res.set('X-Blob-Id', row.id)
  res.set('X-Blob-Created-At', String(row.created_at))
  fs.createReadStream(blobPath(row.id)).pipe(res)
})