Create new DCYF categories. (#752)

This adds some new categories for DCYF via a data migration. Most of
them are under the Sports & Recreation top-level category, but one is
under Education.

Author: richardxia

db/migrate/20241003020742_add_new_dcyf_categories.rb

@@ -0,0 +1,86 @@
+class AddNewDcyfCategories < ActiveRecord::Migration[6.1]
+  def up
+    ActiveRecord::Base.transaction do
+      # Set this to true to enable assertions
+      @assertions_enabled = true
+
+      MAPPING.each do |top_category, categories|
+        assert_category_exists(top_category)
+
+        categories.each do |category|
+          create_category(category)
+          create_subcategory_relationship(top_category, category)
+        end
+      end
+
+      # Unlike all the other subcategories, this one already exists, but we just
+      # want to link it to another top-level category.
+      assert_category_exists("Playgroups")
+      assert_category_exists("Sports & Recreation")
+      create_subcategory_relationship("Sports & Recreation", "Playgroups")
+    end
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+
+  private
+
+  def assert_category_exists(name)
+    return unless @assertions_enabled
+
+    count = select_value("SELECT COUNT(*) FROM categories WHERE name = $1", "count category #{name}", [name])
+    raise "Expected category #{name} to exist, got #{count} results" unless count == 1
+  end
+
+  def assert_category_does_not_exist(name)
+    return unless @assertions_enabled
+
+    count = select_value("SELECT COUNT(*) FROM categories WHERE name = $1", "count category #{name}", [name])
+    raise "Expected category #{name} to not exist, got #{count} results" unless count == 0
+  end
+
+  def create_category(name)
+    assert_category_does_not_exist name
+
+    exec_query <<-SQL, "create category #{name}", [name]
+      INSERT INTO categories (name, created_at, updated_at)
+        VALUES ($1, now(), now())
+        ON CONFLICT (name) DO NOTHING;
+    SQL
+  end
+
+  def category_id(name)
+    id = select_value("SELECT id FROM categories WHERE name = $1", "get category id #{name}", [name])
+    raise "Category #{name} does not exist" if id.nil?
+    id
+  end
+
+  def create_subcategory_relationship(top_category, subcategory)
+    top_category_id = category_id(top_category)
+    subcategory_id = category_id(subcategory)
+    exec_query <<-SQL, "create subcategory relationship #{top_category} -> #{subcategory}", [top_category_id, subcategory_id]
+      INSERT INTO category_relationships (parent_id, child_id)
+        VALUES ($1, $2);
+    SQL
+  end
+
+
+  MAPPING = {
+    "Education" => [
+      "Truancy Prevention",
+    ],
+    "Sports & Recreation" => [
+      "Board Games",
+      "Circus Arts",
+      "Cycling",
+      "Meditation",
+      "Pilates",
+      "Rock Climbing",
+      "Ropes Course",
+      "Sports Programs",
+      "Zumba",
+    ],
+  }
+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_08_19_053931) do
+ActiveRecord::Schema.define(version: 2024_10_03_020742) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"