frontend/src/services/apiClient.js

import { useAuthStore } from '@/stores/authStore.js'
import { BASE_URL } from '@/main.js'


let isRefreshing = false
let refreshPromise = null

function createConfig(options = {}) {
  const authStore = useAuthStore()
  const headers = {
    'Content-Type': 'application/json',
    ...options.headers,
  }

  if (authStore.accessToken) {
    headers['Authorization'] = `Bearer ${authStore.accessToken}`
  }

  return {
    headers,
    credentials: 'include',
    ...options,
  }
}

async function refreshAccessToken() {
  const authStore = useAuthStore()

  if (isRefreshing) return refreshPromise

  isRefreshing = true
  refreshPromise = fetch(`${BASE_URL}/user/auth/refresh`, {
    method: 'POST',
    credentials: 'include',
  })

    .then(async (res) => {
      if (!res.ok) throw new Error('Failed to refresh access token')
      return await res.json()
    })

    .then((data) => {
      const token = data.access_token

      if (!token) {
        throw new Error('No access_token in refresh response')
      }

      authStore.setToken(data.access_token)


      return data
    })

    .catch((error) => {
      throw error
    })

    .finally(() => {
      isRefreshing = false
      refreshPromise = null
    })

  return refreshPromise
}

async function request(url, options = {}, isRetry = false) {
  const config = createConfig(options)

  const response = await fetch(`${BASE_URL}${url}`, config)

  if (response.status === 401 && !isRetry) {
    try {
      const data = await refreshAccessToken()

      const token = data.access_token
      if (!token) {
        throw new Error('Refresh response did not contain access_token')
      }

      const newOptions = {
        ...options,
        headers: {
          ...options.headers,
          'Authorization': `Bearer ${token}`,
        },
      }
      return await request(url, newOptions, true)
    } catch (e) {
      const authStore = useAuthStore()
      authStore.forceLogout()
      throw e
    }
  }

  if (!response.ok) {
    let errorData
    try {
      errorData = await response.json()
    } catch {
      errorData = {}
    }
    throw new Error(errorData.message || `HTTP Error: ${response.status}`)
  }

  let data = null
  const contentType = response.headers.get('content-type')
  if (contentType?.includes('application/json')) {
    try {
      data = await response.json()
    } catch (e) {
      console.warn('Failed to parse JSON response', e)
    }
  }

  return {
    status: response.status,
    ok: response.ok,
    data,
  }
}

export const apiClient = {
  get: (url, params = {}) => {
    const queryString = new URLSearchParams(params).toString();
    const fullUrl = queryString ? `${url}?${queryString}` : url;
    return request(fullUrl, { method: 'GET' });
  },
  post: (url, data) => {
    const isFormData = data instanceof FormData

    return request(url, {
      method: 'POST',
      body: isFormData ? data : JSON.stringify(data),
      headers: isFormData
        ? {}
        : { 'Content-Type': 'application/json' }
    })
  },
  put: (url, data) => request(url, {
    method: 'PUT',
    body: JSON.stringify(data),
  }),
  delete: (url) => request(url, { method: 'DELETE' }),
}