import React, { useReducer } from 'react'

export const WizardContext = React.createContext()

export const ACTIONS = {
  NEXT_STEP: 'nextStep',
  PREV_STEP: 'prevStep',
  SET_FORM_DATA: 'setFormData',
}

function reducer(state, action) {
  switch (action.type) {
    case ACTIONS.NEXT_STEP:
      return {
        ...state,
        currentStep: state.currentStep + 1, // wizards steps unkown here
      }
    case ACTIONS.PREV_STEP:
      return {
        ...state,
        currentStep: Math.max(0, state.currentStep - 1),
      }
    case ACTIONS.SET_FORM_DATA:
      return {
        ...state,
        formData: {
          ...state.formData,
          ...action.payload,
        },
      }
    default:
      throw new Error(`Unkown Action type ${action.type}`)
  }
}

function debugReducer(state, action) {
  console.debug('applying action', action)
  const newState = reducer(state, action)
  console.debug(newState)
  return newState
}

async function createBooking(state) {
  const { name, email, startDate, endDate } = state.formData
  const response = await fetch('/api/booking', {
    method: 'POST',
    mode: 'cors',
    cache: 'no-cache',
    credentials: 'same-origin',
    headers: {
      'Content-Type': 'application/json',
    },
    referrerPolicy: 'no-referrer',
    body: JSON.stringify({ name, email, startDate, endDate }),
  })

  return response.json()
}

const initialState = {
  formData: {
    name: 'Thomas Ruoff',
    email: 'thomasruoff@gmail.com',
    multipleDays: null,
  },
  currentStep: 0,
  bookedOn: [
    '2020-07-10',
    '2020-07-11',
    '2020-07-12',
    '2020-07-23',
    '2020-08-01',
  ],
}

export default function WizardStore({ children }) {
  const [state, dispatch] = useReducer(debugReducer, initialState)

  const onSubmit = () => createBooking(state)

  return (
    <WizardContext.Provider value={{ state, dispatch, onSubmit }}>
      {children}
    </WizardContext.Provider>
  )
}