oil-formula-calculator/frontend/src/composables/useApi.js

const API_BASE = ''  // same origin, uses vite proxy in dev

export function getToken() {
  return localStorage.getItem('oil_auth_token') || ''
}

export function setToken(token) {
  if (token) localStorage.setItem('oil_auth_token', token)
  else localStorage.removeItem('oil_auth_token')
}

function buildHeaders(extra = {}) {
  const headers = { 'Content-Type': 'application/json', ...extra }
  const token = getToken()
  if (token) headers['Authorization'] = 'Bearer ' + token
  return headers
}

async function request(path, opts = {}) {
  const headers = buildHeaders(opts.headers)
  const res = await fetch(API_BASE + path, { ...opts, headers })
  return res
}

async function requestJSON(path, opts = {}) {
  const res = await request(path, opts)
  if (!res.ok) {
    let msg = `${res.status}`
    try {
      const body = await res.json()
      msg = body.detail || body.message || msg
    } catch {}
    const err = new Error(msg)
    err.status = res.status
    throw err
  }
  return res.json()
}

// api is callable as api(path, opts) → raw Response
// AND has convenience methods: api.get(), api.post(), api.put(), api.delete()
function apiFn(path, opts = {}) {
  return request(path, opts)
}

apiFn.raw = request
apiFn.get = (path) => requestJSON(path)
apiFn.post = (path, body) => requestJSON(path, { method: 'POST', body: JSON.stringify(body) })
apiFn.put = (path, body) => requestJSON(path, { method: 'PUT', body: JSON.stringify(body) })
apiFn.del = (path) => requestJSON(path, { method: 'DELETE' })
apiFn.delete = (path) => requestJSON(path, { method: 'DELETE' })

export const api = apiFn