Add bare-bones rails nc_mall:sync task, incl. NCMallRecord model

Currently we only load the homepage, so there's only actually one
wearable item to sync up! But here's the task to do it!

To do this, we also created the backing model NCMallRecord, where we'll
save the current NC Mall state!

app/models/nc_mall_record.rb

@@ -0,0 +1,3 @@
+class NCMallRecord < ApplicationRecord
+  belongs_to :item
+end

app/services/nc_mall.rb

@@ -72,8 +72,8 @@ module NCMall
 
 		{
 			price: discount_price,
-			start: item_info["discountBegin"],
-			end: item_info["discountEnd"],
+			begins_at: item_info["discountBegin"],
+			ends_at: item_info["discountEnd"],
 		}
 	end
 

db/migrate/20240507235742_create_nc_mall_records.rb

@@ -0,0 +1,13 @@
+class CreateNCMallRecords < ActiveRecord::Migration[7.1]
+  def change
+    create_table :nc_mall_records do |t|
+      t.references :item, type: :integer, null: false, foreign_key: true
+      t.integer :price, null: false
+      t.integer :discount_price
+      t.datetime :discount_begins_at
+      t.datetime :discount_ends_at
+
+      t.timestamps
+    end
+  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[7.1].define(version: 2024_05_02_195157) do
+ActiveRecord::Schema[7.1].define(version: 2024_05_07_235742) do
   create_table "alt_styles", charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|
     t.integer "species_id", null: false
     t.integer "color_id", null: false
@@ -154,6 +154,17 @@ ActiveRecord::Schema[7.1].define(version: 2024_05_02_195157) do
     t.string "pet_name", limit: 128, null: false
   end
 
+  create_table "nc_mall_records", charset: "utf8mb4", collation: "utf8mb4_general_ci", force: :cascade do |t|
+    t.integer "item_id", null: false
+    t.integer "price", null: false
+    t.integer "discount_price"
+    t.datetime "discount_begins_at"
+    t.datetime "discount_ends_at"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["item_id"], name: "index_nc_mall_records_on_item_id"
+  end
+
   create_table "neopets_connections", id: :integer, charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|
     t.integer "user_id"
     t.string "neopets_username"
@@ -278,5 +289,6 @@ ActiveRecord::Schema[7.1].define(version: 2024_05_02_195157) do
 
   add_foreign_key "alt_styles", "colors"
   add_foreign_key "alt_styles", "species"
+  add_foreign_key "nc_mall_records", "items"
   add_foreign_key "outfits", "alt_styles"
 end

lib/tasks/nc_mall.rake

@@ -0,0 +1,60 @@
+namespace :nc_mall do
+	desc "Sync our NCMallRecord table with the live NC Mall"
+	task :sync => :environment do
+		# Log to STDOUT.
+		Rails.logger = Logger.new(STDOUT)
+
+		# First, load all records of what's being sold in the live NC Mall.
+		# TODO: Load from other pages, too!
+		live_item_records = NCMall.load_home_page[:items]
+
+		# Then, get the existing NC Mall records in our database. (We include the
+		# items, to be able to output the item name during logging.)
+		existing_records = NCMallRecord.includes(:item).all
+		existing_records_by_item_id = existing_records.to_h { |r| [r.item_id, r] }
+
+		# Additionally, check which of the item IDs in the live records are items
+		# we've seen before. (We'll skip records for items we don't know.)
+		live_item_ids = live_item_records.map { |r| r[:id] }
+		recognized_item_ids = Item.where(id: live_item_ids).pluck(:id).to_set
+		Rails.logger.debug "We recognize #{recognized_item_ids.size} of these items"
+
+		# For each record in the live NC Mall, check if there's an existing record.
+		# If so, update it, and remove it from the existing records hash. If not,
+		# create it.
+		live_item_records.each do |record_data|
+			# If we don't recognize this item ID in our database already, skip it.
+			next unless recognized_item_ids.include?(record_data[:id])
+
+			record = existing_records_by_item_id.delete(record_data[:id]) ||
+				NCMallRecord.new
+			record.item_id = record_data[:id]
+			record.price = record_data[:price]
+			record.discount_price = record_data.dig(:discount, :price)
+			record.discount_begins_at = record_data.dig(:discount, :begins_at)
+			record.discount_ends_at = record_data.dig(:discount, :ends_at)
+			if record.save
+				Rails.logger.info "Saved record for item #{record_data[:name]}"
+			else
+				Rails.logger.error "Failed to save record for item " +
+					"#{record_data[:name]}: " +
+					"#{record.errors.full_messages.join("; ")}: " +
+					"#{record.inspect}"
+			end
+		end
+
+		# For each existing record remaining in the existing records hash, this
+		# means there was no live record corresponding to it during this sync.
+		# Delete it!
+		existing_records_by_item_id.values.each do |record|
+			item_name = record.item&.name || "<item not found>"
+			if record.destroy
+				Rails.logger.info "Destroyed record #{record.id} for item " + 
+					"#{item_name}"
+			else
+				Rails.logger.error "Failed to destroy record #{record.id} for " +
+					"item #{item_name}: #{record.inspect}"
+			end
+		end
+	end
+end