Implement External Listing Service

[mcgarrye]

We need to implement the functionality of exposing and ingesting listings. To do this we will need two functions that work together across Bloom instances.
How it will work:

• Externalize function will allow external versions of the site to access basic internal data with ids, names and for listings contentUpdatedAt
• Ingest function will allow the system to connect to an external version of the site through the export function and to pull in external listings

Externalize function (GET)

• Load data from the following source with the following data
• Jurisdictions - {id, name}
• Listings - {id, contentUpdatedAt, jurisdictionId}
• Reserved Community Types - {id, name}
• Unit Types - {id, name}
• Return in an object

Ingest function (PUT)

• Takes in
  • target jurisdiction name,
  • internal matching jurisdiction id,
  • external api url
• Call external api GET export function endpoint
• Map the following:
  • The target jurisdiction name to a jurisdiction in the returned list
  • The returned reservedCommunityTypes to internal types
    • If a reservedCommunityType cannot be matched, log error of missing RCT
  • The returned unitTypes to internal types
• Load existing external listing ids and content_updated_at’s that match internal jurisdiction id and the returned external jurisdiction id
• Compare loaded listings to response (when creating/recreating, if the listing has a missing RCT, do not create and log warning)
  • If listing is not in response, delete
  • If listing is in response and has a newer content_updated_at, delete, call /listings/external/{id} and recreate
  • If listing is in response and same content_updated_at, continue
  • If new listing is in the response, create