import { ref, watch, type Ref } from 'vue'
import { useAuthStore } from '~/stores/auth.store'

export function useSftp(sessionId: Ref<string | null>) {
  const auth = useAuthStore()
  let ws: WebSocket | null = null
  const entries = ref<any[]>([])
  const currentPath = ref('/')
  const fileContent = ref<{ path: string; content: string } | null>(null)
  const transfers = ref<any[]>([])
  const activeDownloads = new Map<string, { path: string; chunks: string[]; total: number }>()

  let pendingList: string | null = null

  function connect() {
    const wsUrl = `${location.protocol === 'https:' ? 'wss' : 'ws'}://${location.host}/api/ws/sftp?token=${auth.token}`
    ws = new WebSocket(wsUrl)

    ws.onopen = () => {
      console.log('[SFTP] WS open, sessionId=', sessionId.value, 'pendingList=', pendingList)
      if (pendingList !== null) {
        // Send directly — don't rely on send() guard since we know WS is open
        const path = pendingList
        pendingList = null
        if (sessionId.value) {
          ws!.send(JSON.stringify({ type: 'list', path, sessionId: sessionId.value }))
        } else {
          console.warn('[SFTP] No sessionId available yet, cannot list')
          pendingList = path // put it back
        }
      }
    }

    ws.onmessage = (event) => {
      console.log('[SFTP] WS message received, raw length:', event.data?.length, 'type:', typeof event.data)
      const msg = JSON.parse(event.data)
      console.log('[SFTP] Parsed message type:', msg.type, 'entries:', msg.entries?.length)
      switch (msg.type) {
        case 'list':
          entries.value = msg.entries.sort((a: any, b: any) => {
            if (a.isDirectory !== b.isDirectory) return a.isDirectory ? -1 : 1
            return a.name.localeCompare(b.name)
          })
          currentPath.value = msg.path
          console.log('[SFTP] entries.value set, count:', entries.value.length)
          break
        case 'fileContent':
          fileContent.value = { path: msg.path, content: msg.content }
          break
        case 'saved':
          fileContent.value = null
          list(currentPath.value)
          break
        case 'uploaded':
          list(currentPath.value)
          break
        case 'downloadStart':
          activeDownloads.set(msg.transferId, { path: msg.path, chunks: [], total: msg.total })
          break
        case 'downloadChunk':
          const dl = activeDownloads.get(msg.transferId)
          if (dl) dl.chunks.push(msg.data)
          break
        case 'downloadComplete': {
          const transfer = activeDownloads.get(msg.transferId)
          if (transfer) {
            const binary = atob(transfer.chunks.join(''))
            const bytes = new Uint8Array(binary.length)
            for (let i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i)
            const blob = new Blob([bytes])
            const url = URL.createObjectURL(blob)
            const a = document.createElement('a')
            a.href = url
            a.download = transfer.path.split('/').pop() || 'download'
            document.body.appendChild(a)
            a.click()
            document.body.removeChild(a)
            URL.revokeObjectURL(url)
            activeDownloads.delete(msg.transferId)
          }
          break
        }
        case 'error':
          console.error('SFTP error:', msg.message)
          break
      }
    }

    ws.onerror = (event) => {
      console.error('[SFTP] WS error event:', event)
    }

    ws.onclose = (event) => {
      console.log('[SFTP] WS closed, code:', event.code, 'reason:', event.reason, 'wasClean:', event.wasClean)
    }

    return ws
  }

  function send(msg: any) {
    if (ws?.readyState === WebSocket.OPEN && sessionId.value) {
      ws.send(JSON.stringify({ ...msg, sessionId: sessionId.value }))
    }
  }

  function list(path: string) {
    if (ws && ws.readyState === WebSocket.OPEN) {
      send({ type: 'list', path })
    } else {
      pendingList = path
    }
  }
  function readFile(path: string) { send({ type: 'read', path }) }
  function writeFile(path: string, data: string) { send({ type: 'write', path, data }) }
  function mkdir(path: string) { send({ type: 'mkdir', path }) }
  function rename(oldPath: string, newPath: string) { send({ type: 'rename', oldPath, newPath }) }
  function remove(path: string) { send({ type: 'delete', path }) }
  function chmod(path: string, mode: string) { send({ type: 'chmod', path, mode }) }
  function download(path: string) { send({ type: 'download', path }) }
  function upload(path: string, dataBase64: string) { send({ type: 'upload', path, data: dataBase64 }) }

  // If sessionId arrives after WS is already open, send any pending list
  watch(sessionId, (newId) => {
    if (newId && pendingList !== null && ws?.readyState === WebSocket.OPEN) {
      const path = pendingList
      pendingList = null
      ws!.send(JSON.stringify({ type: 'list', path, sessionId: newId }))
    }
  })

  function disconnect() {
    ws?.close()
    ws = null
  }

  return {
    entries, currentPath, fileContent, transfers,
    connect, disconnect, list, readFile, writeFile, mkdir, rename, remove, chmod, download, upload,
  }
}