Add boosted_category_id column and add to Algolia index. (#748)

This adds a `boosted_category_id` column to Services, which is a
nullable foreign key to the Categories table. This is intended to be
used by the frontend code through Algolia as a possible target of the
optional filters feature of Algolia, allowing us to boost search
rankings for specific services on specific pages.

This column is added to the Algolia index as `boosted_category`, which
holds the string name of the category, and we also add it to the
`attributesForFaceting` list so that it can be used for optional
filters.

Finally, we change the Algolia index ranking order from its default by
placing `geo` after `filters`. This is needed in order for optional
filters to have higher precedence than geolocation.

app/models/service.rb

@@ -9,6 +9,7 @@ class Service < ActiveRecord::Base
 
   belongs_to :resource, required: true, touch: true
   belongs_to :program
+  belongs_to :boosted_category, class_name: 'Category'
   has_many :notes, dependent: :destroy
   has_many :feedbacks, dependent: :destroy
   has_many :textings
@@ -37,7 +38,11 @@ class Service < ActiveRecord::Base
                   index_name: "#{Rails.configuration.x.algolia.index_prefix}_services_search",
                   id: :algolia_id do
       # specify the list of attributes available for faceting
-      attributesForFaceting %i[categories open_times eligibilities associated_sites type]
+      attributesForFaceting %i[categories open_times eligibilities associated_sites type boosted_category]
+
+      # Default has "geo" before "filters", but we need it after if we want
+      # optional filters to have higher priority than distance.
+      ranking %w[typo words filters geo proximity attribute exact custom]
 
       # Define attributes used to build an Algolia record
       add_attribute :status
@@ -127,6 +132,10 @@ class Service < ActiveRecord::Base
         categories.map(&:name)
       end
 
+      add_attribute :boosted_category do
+        boosted_category&.name
+      end
+
       add_attribute :use_resource_schedule
 
       add_attribute :eligibilities do

db/migrate/20240804222349_add_boosted_category_to_services.rb

@@ -0,0 +1,5 @@
+class AddBoostedCategoryToServices < ActiveRecord::Migration[6.1]
+  def change
+    add_reference :services, :boosted_category, foreign_key: { to_table: :categories }
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2024_07_02_155441) do
+ActiveRecord::Schema.define(version: 2024_08_04_222349) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -418,6 +418,8 @@
     t.integer "source_attribution", default: 0
     t.text "internal_note"
     t.string "short_description"
+    t.bigint "boosted_category_id"
+    t.index ["boosted_category_id"], name: "index_services_on_boosted_category_id"
     t.index ["contact_id"], name: "index_services_on_contact_id"
     t.index ["funding_id"], name: "index_services_on_funding_id"
     t.index ["program_id"], name: "index_services_on_program_id"
@@ -521,6 +523,7 @@
   add_foreign_key "schedule_days", "schedules"
   add_foreign_key "schedules", "resources"
   add_foreign_key "schedules", "services"
+  add_foreign_key "services", "categories", column: "boosted_category_id"
   add_foreign_key "services", "contacts"
   add_foreign_key "services", "fundings"
   add_foreign_key "services", "programs"