import { promises as fs } from 'fs'
import { encryptObject, decryptObject } from './encryption.js'
import { getServerDataPath } from './paths.js'

const FILE = getServerDataPath('mytischtennis-connection.json')

function encryptionKey() {
  const key = process.env.ENCRYPTION_KEY
  if (!key) throw new Error('ENCRYPTION_KEY ist für die myTischtennis-Verbindung erforderlich.')
  return key
}

export async function readMyTischtennisConnection() {
  try {
    const stored = JSON.parse(await fs.readFile(FILE, 'utf8'))
    return decryptObject(stored.encrypted, encryptionKey())
  } catch (error) {
    if (error?.code === 'ENOENT') return null
    throw error
  }
}

export async function saveMyTischtennisConnection(connection) {
  const payload = {
    version: 1,
    encrypted: encryptObject(connection, encryptionKey())
  }
  await fs.mkdir(getServerDataPath(), { recursive: true })
  await fs.writeFile(FILE, `${JSON.stringify(payload)}\n`, { encoding: 'utf8', mode: 0o600 })
}

export function publicConnectionStatus(connection) {
  if (!connection) return { configured: false }
  const email = String(connection.email || '')
  const [name, domain] = email.split('@')
  return {
    configured: true,
    email: name ? `${name.slice(0, 2)}${'•'.repeat(Math.max(1, name.length - 2))}${domain ? `@${domain}` : ''}` : null,
    association: connection.association || null,
    clubId: connection.clubId || null,
    lastSuccessfulImportAt: connection.lastSuccessfulImportAt || null,
    lastImportError: connection.lastImportError || null
  }
}