Screen SAP SuccessFactors applications with HireLayer

const HIRELAYER = 'https://hirelayer.co'
const SF = `https://${process.env.SF_API_SERVER}/odata/v2`
const apiKey = { 'X-API-Key': process.env.HIRELAYER_API_KEY! }

// OData v2 call with an OAuth 2.0 access token (SAML bearer, /oauth/token)
async function sf(path: string, method = 'GET', body?: object, extra = {}) {
  const res = await fetch(SF + path, {
    method,
    headers: {
      Authorization: `Bearer ${await sfToken()}`,
      Accept: 'application/json',
      'Content-Type': 'application/json',
      ...extra,
    },
    body: body && JSON.stringify(body),
  })
  // 429 + Retry-After when a rate limit is enforced
  if (!res.ok) throw new Error(`SuccessFactors ${res.status}: ${await res.text()}`)
  const text = await res.text() // MERGE answers with an empty body
  return text ? JSON.parse(text) : null
}

// applicationId comes from your poll on JobApplication, or from an
// Integration Center job that runs when the application status changes
export async function screen(applicationId: string) {
  const { d: app } = await sf(`/JobApplication('${applicationId}')?$expand=resume`)
  if (!app.resume?.fileContent) return // no resume, or hidden by read audit

  // 1. Parse the resume (fileContent is base64)
  const form = new FormData()
  const file = new Blob([Buffer.from(app.resume.fileContent, 'base64')])
  form.append('file', file, app.resume.fileName)
  form.append('application_id', applicationId)
  const parsed = await fetch(`${HIRELAYER}/api/v3/parser`, {
    method: 'POST', headers: apiKey, body: form, signal: AbortSignal.timeout(150_000),
  }).then((r) => r.json())

  // 2. Score with the criteria saved for this requisition
  const criteria = await loadCriteria(app.jobReqId)
  const match = await fetch(`${HIRELAYER}/api/v1/matching/job-candidate`, {
    method: 'POST',
    headers: { ...apiKey, 'Content-Type': 'application/json' },
    body: JSON.stringify({
      job_text: criteria.jobText,
      candidate_text: parsed.info_resume.text,
      matching_criteria: criteria.items,
    }),
  }).then((r) => r.json())

  // 3. Write two custom fields of your application template
  await sf(`/JobApplication('${applicationId}')`, 'POST', {
    hirelayerScore: String(match.score),
    hirelayerSummary: match.summary,
  }, { 'X-HTTP-METHOD': 'MERGE' })
}