middleware

import { RECEIVE_ERROR } from '../core/Constants'
import { 
  REQUEST_GET, 
  REQUEST_GET_ONE,
  REQUEST_POST,
  REQUEST_PATCH,
  REQUEST_PUT,
  REQUEST_DELETE
} from '../core/RequestConstants'
import { handleError } from '../actions/app'

const callAPI = (type, endpoint, params) => {
  switch (type) {
    case REQUEST_GET:
      if (params) return endpoint.getAll(params)  // params exist
      else return endpoint.getAll() // no params

      break;
    case REQUEST_GET_ONE:
      if (params) return endpoint.get(params)
      else return endpoint.get()

      break;
    case REQUEST_POST:
      if (params) return endpoint.post(params)
      else return endpoint.post()

      break;
    case REQUEST_PATCH:
      if (params) return endpoint.patch(params)
      else return endpoint.patch()

      break;
    case REQUEST_PUT:
      if (params) return endpoint.put(params)
      else return endpoint.put()

      break;
    case REQUEST_DELETE:
      if (params) return endpoint.delete(params)
      else return endpoint.delete()

      break;
    default:
      if (params) return endpoint.getAll(params)  // params exist
      else return endpoint.getAll() // no params
  }
}

const apiMiddleware = ({dispatch, getState}) => {
  return next => action => {
    const { type, endpoint, request, params, payload } = action

    // normal action, pass it on
    if (!endpoint) return next(action)

    dispatch({
      type,
      status: 'request',
      payload
    })

    return new Promise(function(resolve, reject) {
      callAPI(request, endpoint, params)
      .then(response => {
        resolve(response)

        return dispatch({
          type,
          status: 'success',
          response,
          payload
        })
      }, error => {
        reject(error)

        dispatch({
          type,
          status: 'error'
        });
        return dispatch(handleError(error))
      })
    });
  }
}

export default apiMiddleware