collection-loader.js

const get = require('lodash/get')
const flatMap = require('lodash/flatMap')

function loadCollectionItems (
  client,
  collections,
  { storyFields, storyLimits = {}, defaultNestedLimit, customLayouts = [], previewId = '', qtInternalAppsKey = '' }
) {
  const bulkRequestBody = collections.reduce((acc, collection, index) => {
    let limit = storyLimits[get(collection, ['associated-metadata', 'layout'], '')]
    const customLayout = get(customLayouts, [index])
    if (customLayout) {
      limit = get(customLayout, ['storyLimit'])
    }

    if (!limit && get(collection, ['childCollectionLimit'])) {
      limit = get(collection, ['childCollectionLimit'])
    }

    if (!limit && defaultNestedLimit) {
      limit = defaultNestedLimit
    }

    return Object.assign(acc, {
      [`${collection.slug}-${index}`]: {
        _type: 'collection',
        slug: collection.slug,
        'story-fields': storyFields,
        limit: limit
      }
    })
  }, {})
  const opts = { previewId, qtInternalAppsKey }
  return client.getInBulk({ requests: bulkRequestBody }, opts).then(response => response.results)
}

// Ugly. This function updates all the items in place.
// However, this is way more readable than a pure version
function updateItemsInPlace (
  client,
  depth,
  items,
  {
    storyFields,
    storyLimits,
    defaultNestedLimit,
    nestedCollectionLimit,
    collectionOfCollectionsIndexes = [],
    customLayouts = [],
    previewId = "",
    qtInternalAppsKey = ""
  }
) {
  const collections = items.filter(item => item && item.type == 'collection')

  if (depth == 0 || collections.length == 0) return Promise.resolve()

  return loadCollectionItems(client, collections, {
    storyFields,
    storyLimits,
    defaultNestedLimit,
    customLayouts,
    previewId,
    qtInternalAppsKey
  }).then(collectionSlugToCollection => {
    collections.forEach((collection, index) => {
      const slugWithIndex = `${collection.slug}-${index}`
      collection.summary = get(collectionSlugToCollection, [slugWithIndex, 'summary'], '')
      collection.automated = get(collectionSlugToCollection, [slugWithIndex, 'automated'])
      collection['collection-cache-keys'] = get(
        collectionSlugToCollection,
        [slugWithIndex, 'collection-cache-keys'],
        []
      )
      collection.items = get(collectionSlugToCollection, [slugWithIndex, 'items'], [])
      if (nestedCollectionLimit && collection.items) {
        const customLayout = get(customLayouts, [index])
        collection.items.forEach((item, index) => {
          if (item.type === 'collection') {
            if (customLayout && customLayout.nestedCollectionLimit) {
              item.childCollectionLimit = get(customLayout, ['nestedCollectionLimit', index])
            } else if (nestedCollectionLimit[get(collection, ['associated-metadata', 'layout'])]) {
              item.childCollectionLimit =
                nestedCollectionLimit[get(collection, ['associated-metadata', 'layout'])][index]
            }
          }
        })
      }
    })

    if (collectionOfCollectionsIndexes.length) {
      const updatedCollections = collections
        .filter((_, index) => collectionOfCollectionsIndexes.includes(index))
        .map(childCollection => {
          return updateItemsInPlace(client, 1, childCollection.items, {
            storyFields,
            storyLimits,
            defaultNestedLimit,
            previewId,
            qtInternalAppsKey
          })
        })
      return Promise.all(updatedCollections).then(collections => collections)
    } else {
      return updateItemsInPlace(
        client,
        depth - 1,
        flatMap(collections, collection => collection.items),
        {
          storyFields,
          storyLimits,
          defaultNestedLimit,
          previewId,
          qtInternalAppsKey
        }
      )
    }
  })
}

function loadNestedCollectionData (
  client,
  collection,
  {
    depth,
    storyFields,
    storyLimits,
    defaultNestedLimit,
    nestedCollectionLimit,
    collectionOfCollectionsIndexes,
    customLayouts,
    previewId,
    qtInternalAppsKey
  }
) {
  return updateItemsInPlace(client, depth, collection.items, {
    storyFields,
    storyLimits,
    defaultNestedLimit,
    nestedCollectionLimit,
    collectionOfCollectionsIndexes,
    customLayouts,
    previewId,
    qtInternalAppsKey
  }).then(() => collection)
}

module.exports = { loadNestedCollectionData }