import Prismic from '@prismicio/client'
import { PrismicQuery, PrismicQueryTypes } from '../types'

const transformQuery = (query: PrismicQuery | PrismicQuery[]): string | string[] => {
  const predict = (method, args) => Prismic.Predicates[method](...args)

  const queryContainer = Array.isArray(query) ? query : [query]

  const queries = queryContainer.map(q => Object.keys(q).map<string>((key) => {
    const current: PrismicQueryTypes = q[key]

    if (!Prismic.Predicates[key]) {
      return undefined
    }

    const {
      fragment, after, before, day, documentId,
      hour, latitude, longitude, maxResults, month,
      radius, value, values, year
    } = current

    switch (true) {
      case values !== undefined:
        return predict(key, [fragment, values])
      case value !== undefined:
        return predict(key, [fragment, value])
      case documentId !== undefined && maxResults !== undefined:
        return predict(key, [documentId, maxResults])
      case before !== undefined && after !== undefined:
        return predict(key, [fragment, before, after])
      case before !== undefined:
        return predict(key, [fragment, before])
      case after !== undefined:
        return predict(key, [fragment, after])
      case latitude !== undefined && longitude !== undefined && radius !== undefined:
        return predict(key, [fragment, latitude, longitude, radius])
      case year !== undefined:
        return predict(key, [fragment, year])
      case month !== undefined:
        return predict(key, [fragment, month])
      case day !== undefined:
        return predict(key, [fragment, day])
      case hour !== undefined:
        return predict(key, [fragment, hour])
      default:
        return predict(key, [fragment])
    }
  }))

  const flatArray = [].concat(...queries.filter(queryElement => queryElement !== undefined))

  return flatArray.length === 1 ? flatArray[0] : flatArray
}

export default transformQuery