export function agentBackendUrl(value, origin) {
  if (/[\r\n\t]/.test(String(value || ''))) throw new Error('Die Serveradresse darf keine Steuerzeichen enthalten.')
  const url = new URL(String(value || '/').trim(), origin)
  if (!['http:', 'https:'].includes(url.protocol) || url.username || url.password || url.search || url.hash) {
    throw new Error('Bitte eine HTTP(S)-Adresse ohne Zugangsdaten, Suchparameter oder Fragment eingeben.')
  }
  return url.toString().replace(/\/+$/, '')
}

function base64(value) {
  const bytes = new TextEncoder().encode(value)
  let binary = ''
  for (const byte of bytes) binary += String.fromCharCode(byte)
  return btoa(binary)
}

export function renderAgentInstaller(bundle, options) {
  if (!/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/i.test(options.agentId)) {
    throw new Error('Ungültige Agent-ID')
  }
  if (!/^fedeo_agent_[a-f0-9]{64}$/.test(options.token)) throw new Error('Bitte den vollständigen Agent-Token eingeben.')
  const url = agentBackendUrl(options.backendUrl)
  if (/\s|["'`\\]/.test(url)) throw new Error('Die Serveradresse enthält ungültige Zeichen.')
  const configuration = [
    `FEDEO_URL=${url}`, `FEDEO_AGENT_TOKEN=${options.token}`,
    'FEDEO_POLL_SECONDS=5', 'FEDEO_SCAN_FORMAT=pdf', 'FEDEO_SCAN_RESOLUTION=300',
    'FEDEO_SCAN_MODE=Color', 'FEDEO_SCAN_TIMEOUT_SECONDS=900',
    'FEDEO_SCAN_POSTPROCESS=false', 'FEDEO_SCAN_POSTPROCESS_PROFILE=document', '',
  ].join('\n')
  const replacements = {
    AGENT_ID: options.agentId, AUTOSTART: String(Boolean(options.autostart)),
    PAYLOAD_BASE64: base64(JSON.stringify(bundle.files)), CONFIG_BASE64: base64(configuration),
  }
  return bundle.installerTemplate.replace(/@@([A-Z0-9_]+)@@/g, (_, key) => {
    if (!(key in replacements)) throw new Error('Unbekannter Platzhalter im Installationspaket')
    return replacements[key]
  })
}

export const ix1600ScanDefaults = {
  format: 'pdf', resolution: 300, mode: 'Color', source: 'ADF Duplex',
  paperSize: 'A4', postprocess: false, postprocessProfile: 'document',
}

export function agentSetupReady(agent, since = 0, now = Date.now()) {
  const lastSeen = Date.parse(agent?.lastSeenAt || '')
  return Boolean(agent?.active && Number.isFinite(lastSeen) && lastSeen >= since && now - lastSeen < 120000)
}