import { csrfHeader } from '../lib/csrf'
import { ApiError, formatApiErrorDetail } from './errors'

export type JsonRequestOptions = Omit<RequestInit, 'body'> & { body?: unknown }

function apiUrl(path: string) {
  return path.startsWith('/api/') ? path : `/api/v1${path.startsWith('/') ? path : `/${path}`}`
}

async function apiFetch(path: string, options: RequestInit = {}) {
  const headers = new Headers(options.headers)
  const csrf = csrfHeader(options.method)
  if (csrf['x-csrf-token']) headers.set('x-csrf-token', csrf['x-csrf-token'])
  const response = await fetch(apiUrl(path), { credentials: 'include', ...options, headers })
  if (!response.ok) {
    const contentType = response.headers.get('content-type') || ''
    const body = contentType.includes('json') ? await response.json().catch(() => ({})) : await response.text().catch(() => '')
    const detail = body && typeof body === 'object' && 'detail' in body ? body.detail : body
    const code = body && typeof body === 'object' && typeof body.code === 'string'
      ? body.code
      : detail && typeof detail === 'object' && !Array.isArray(detail) && typeof detail.code === 'string' ? detail.code : undefined
    throw new ApiError(formatApiErrorDetail(detail), response.status, code, detail)
  }
  return response
}

export async function requestJson<T>(path: string, options: JsonRequestOptions = {}): Promise<T> {
  const headers = new Headers(options.headers)
  const { body: ignoredBody, ...requestOptions } = options
  void ignoredBody
  const body = options.body === undefined ? undefined : JSON.stringify(options.body)
  if (body !== undefined) headers.set('content-type', 'application/json')
  const response = await apiFetch(path, { ...requestOptions, headers, body })
  return response.status === 204 ? undefined as T : await response.json() as T
}

export async function requestBlob(path: string, options: RequestInit = {}): Promise<Blob> {
  return (await apiFetch(path, options)).blob()
}

export async function uploadJson<T>(path: string, file: File, options: Omit<RequestInit, 'body'> = {}): Promise<T> {
  const form = new FormData()
  form.append('file', file)
  const response = await apiFetch(path, { ...options, method: options.method ?? 'POST', body: form })
  return response.status === 204 ? undefined as T : await response.json() as T
}

export { ApiError } from './errors'