import {AnyJson, ApiResponse, HydraMetadata, METADATA_TYPE} from "~/types/data.d";
import Url from "~/services/utils/url";

/**
 * Classe permettant d'assurer la dé-normalization d'un objet Hydra en JSON
 */
class HydraDenormalizer {
  /**
   * Parse une réponse Hydra pour retourner son équivalent en Json
   *
   * @param {AnyJson} data
   * @return {AnyJson} réponse parsée
   */
  public static denormalize (data: AnyJson): ApiResponse {
    if (data['hydra:member']) {
      return HydraDenormalizer.parseCollection(data)
    }

    return HydraDenormalizer.parseItem(data)
  }

  /**
   * Parse une réponse Hydra contenant un item
   *
   * @param hydraData
   * @private
   */
  private static parseItem (hydraData: AnyJson): ApiResponse {
    return {
      data: hydraData,
      metadata: HydraDenormalizer.constructMetadataForItem(hydraData)
    }
  }

  /**
   * Méthode de parsing appelé si on est dans un GET Collection
   *
   * @param {AnyJson} hydraData
   */
  private static parseCollection (hydraData: AnyJson): ApiResponse {
    const collectionResponse:ApiResponse = {
      data:hydraData['hydra:member'],
      metadata : HydraDenormalizer.constructMetadataForCollection(hydraData)
    }

    // collectionResponse.order = {}
    // collectionResponse.search = {}

    // Populate href property for all elements of the collection
    for (const key in collectionResponse.data) {
      const value = collectionResponse.data[key]
      HydraDenormalizer.populateAllData(value)
    }

    // if (typeof (hydraData['hydra:search']) !== 'undefined') {
    //   const collectionSearch = hydraData['hydra:search']['hydra:mapping']
    //   for (const key in collectionSearch) {
    //     const value = collectionSearch[key]
    //     if (value.variable.indexOf('filter[order]') === 0) {
    //       collectionResponse.order[value.property] = value
    //     } else if (value.variable.indexOf('filter[where]') === 0) {
    //       collectionResponse.search[value.property] = value
    //     }
    //   }
    // }

    return collectionResponse
  }

  /**
   * Génère les metadonnées d'un item
   *
   * @param {AnyJson} hydraData
   */
  private static constructMetadataForItem (hydraData: AnyJson): AnyJson {
    const metadata: HydraMetadata = {}

    // if (hydraData['hydra:previous']) {
    //   const iriParts = hydraData['hydra:previous'].split('/')
    //   hydraData.previous = iriParts[iriParts.length - 1]
    // }
    // if (hydraData['hydra:next']) {
    //   const iriParts = hydraData['hydra:next'].split('/')
    //   hydraData.next = iriParts[iriParts.length - 1]
    // }
    // if (hydraData['hydra:totalItems']) {
    //   hydraData.totalItems = hydraData['hydra:totalItems']
    // }
    // if (hydraData['hydra:itemPosition']) {
    //   hydraData.itemPosition = hydraData['hydra:itemPosition']
    // }

    metadata.type = METADATA_TYPE.ITEM

    return metadata

  }

  /**
   * Génère les métadonnées d'une collection
   *
   * @param data
   * @private
   */
  private static  constructMetadataForCollection(data:AnyJson){
    const metadata: HydraMetadata = {
      totalItems: data['hydra:totalItems']
    }

    if(data['hydra:view']){
      metadata.firstPage = HydraDenormalizer.getPageFromUri(data['hydra:view']['hydra:first'], 1) as number
      metadata.lastPage = HydraDenormalizer.getPageFromUri(data['hydra:view']['hydra:last'], 1) as number
      metadata.nextPage = HydraDenormalizer.getPageFromUri(data['hydra:view']['hydra:next']) ?? undefined
      metadata.previousPage = HydraDenormalizer.getPageFromUri(data['hydra:view']['hydra:previous']) ?? undefined
    }

    metadata.type = METADATA_TYPE.COLLECTION

    return metadata
  }

  /**
   * Hydrate l'objet JSON de façon récursive (afin de gérer les objet nested)
   *
   * @param {AnyJson} data
   */
  private static populateAllData (data: AnyJson): void {
    for (const key in data) {
      const value = data[key]
      if (value instanceof Object) {
        HydraDenormalizer.populateAllData(value)
      }
    }
  }

  private static getPageFromUri(uri: string, default_: number | null = null): number | null {
    const url = 'https://foo' + uri // Pour que l'uri partielle soit parsée, on doit y ajouter une url de base bidon
    const page = Url.getParameter(url, 'page')
    return page ? parseInt(page) : default_
  }
}

export default HydraDenormalizer