Update pet state bulk-labeling to skip to next unlabeled if desired

Previously, "Then: Go to unlabeled appearance" would always take you to
the *first* unlabeled appearance in our database.

Now, we go to the *next* unlabeled appearance in the list, relative to
this one.

app/controllers/pet_states_controller.rb

@@ -40,7 +40,8 @@ class PetStatesController < ApplicationController
 	end
 
 	def next_unlabeled_appearance_path
-		unlabeled_appearance = PetState.next_unlabeled_appearance
+		unlabeled_appearance =
+			PetState.next_unlabeled_appearance(after_id: params[:after])
 
 		if unlabeled_appearance
 			edit_pet_type_pet_state_path(

app/helpers/support_form_helper.rb

@@ -1,7 +1,8 @@
 module SupportFormHelper
 	class SupportFormBuilder < ActionView::Helpers::FormBuilder
 		attr_reader :template
-		delegate :capture, :check_box_tag, :content_tag, :params, :render,
+		delegate :capture, :check_box_tag, :concat, :content_tag,
+			:hidden_field_tag, :params, :render,
 			to: :template, private: true
 
 		def errors
@@ -40,8 +41,11 @@ module SupportFormHelper
 			content_tag(:section, class: "actions", &block)
 		end
 
-		def go_to_next_field(**options, &block)
-			content_tag(:label, class: "go-to-next", **options, &block)
+		def go_to_next_field(after: nil, **options, &block)
+			content_tag(:label, class: "go-to-next", **options) do
+				concat hidden_field_tag(:after, after) if after
+				yield
+			end
 		end
 
 		def go_to_next_check_box(value)

app/models/pet_state.rb

@@ -24,6 +24,7 @@ class PetState < ApplicationRecord
 
   scope :newest, -> { order(created_at: :desc) }
   scope :newest_pet_type, -> { joins(:pet_type).merge(PetType.newest) }
+  scope :created_before, ->(time) { where(arel_table[:created_at].lt(time)) }
 
   # A simple ordering that tries to bring reliable pet states to the front.
   scope :emotion_order, -> {
@@ -142,11 +143,39 @@ class PetState < ApplicationRecord
     end
   end
 
-  def self.next_unlabeled_appearance
+  def self.next_unlabeled_appearance(after_id: nil)
     # Rather than just getting the newest unlabeled pet state, prioritize the
     # newest *pet type*. This better matches the user's perception of what the
     # newest state is, because the Rainbow Pool UI is grouped by pet type!
-    needs_labeling.newest_pet_type.newest.first
+    pet_states = needs_labeling.newest_pet_type.newest
+
+    # If `after_id` is given, convert it from a PetState ID to creation
+    # timestamps, and find the next record prior to those timestamps. This
+    # enables skipping past records the user doesn't want to label.
+    if after_id
+      begin
+        after_pet_state = PetState.find(after_id)
+        before_pt_created_at = after_pet_state.pet_type.created_at
+        before_ps_created_at = after_pet_state.created_at
+      rescue ActiveRecord::RecordNotFound
+        Rails.logger.warn "PetState.next_unlabeled_appearance: Could not " +
+          "find pet state ##{after_id}"
+        return nil
+      end
+
+      # Because we sort by `newest_pet_type` first, then breaks ties by
+      # `newest`, our filter needs to operate the same way. Kudos to:
+      # https://brunoscheufler.com/blog/2022-01-01-paginating-large-ordered-datasets-with-cursor-based-pagination
+      pet_states.merge!(
+        PetType.created_before(before_pt_created_at).or(
+          PetType.created_at(before_pt_created_at).and(
+            PetState.created_before(before_ps_created_at)
+          )
+        )
+      )
+    end
+
+    pet_states.first
   end
 end
 

app/models/pet_type.rb

@@ -31,6 +31,12 @@ class PetType < ApplicationRecord
     # We use DTI's creation timestamp as an estimate of when it was released.
     where('created_at <= ?', time)
   }
+  scope :created_before, ->(time) {
+    where(arel_table[:created_at].lt(time))
+  }
+  scope :created_at, ->(time) {
+    where(arel_table[:created_at].eq(time))
+  }
 
   def self.random_basic_per_species(species_ids)
     random_pet_types = []

app/views/pet_states/edit.html.haml

@@ -39,9 +39,10 @@
 	
 	= f.actions do
 		= f.submit "Save changes"
-		= f.go_to_next_field title: "If checked, takes you to the first unlabeled appearance in the database, if any. Useful for labeling in bulk!" do
+		= f.go_to_next_field after: @pet_state.id,
+			title: "If checked, takes you to the first unlabeled appearance in the database, if any. Useful for labeling in bulk!" do
 			= f.go_to_next_check_box "unlabeled-appearance"
-			Then: Go to unlabeled appearance
+			Then: Go to next unlabeled appearance
 
 - content_for :stylesheets do
 	= stylesheet_link_tag "application/breadcrumbs"

spec/models/pet_state_spec.rb

@@ -0,0 +1,105 @@
+require_relative '../rails_helper'
+
+RSpec.describe PetState do
+	fixtures :colors, :species, :zones
+
+	let(:blue) { colors(:blue) }
+	let(:green) { colors(:green) }
+	let(:red) { colors(:red) }
+	let(:acara) { species(:acara) }
+
+	describe ".next_unlabeled_appearance" do
+		before { PetType.destroy_all }
+
+		def create_sa
+			swf_asset = SwfAsset.create!(
+				type: "biology", remote_id: (SwfAsset.maximum(:remote_id) || 0) + 1,
+				url: "https://images.neopets.example/hello.swf",
+				zone: zones(:body), zones_restrict: [], body_id: 0)
+		end
+
+		def create_pt(color, species, created_at = nil)
+			PetType.create! color:, species:, created_at:,
+				body_id: (PetType.maximum(:body_id) || 0) + 1
+		end
+
+		def create_ps(pet_type, pose, created_at = nil, **options)
+			# HACK: PetStates without any assets don't save correctly.
+			# https://github.com/rails/rails/issues/52340
+			swf_assets = [create_sa]
+			PetState.create! pet_type:, pose:, created_at:, swf_assets:,
+				swf_asset_ids: swf_assets.map(&:id), **options
+		end
+
+		it "returns nil where there are no pet states" do
+			expect(PetState.next_unlabeled_appearance).to be_nil
+		end
+
+		it "returns nil where there are only labeled pet states" do
+			pt = PetType.create! color: blue, species: acara, body_id: 1
+			ps = create_ps(pt, "HAPPY_MASC").tap(&:save!)
+			expect(PetState.next_unlabeled_appearance).to be_nil
+		end
+
+		it "returns the only pet state when it is unlabeled" do
+			pt = PetType.create! color: blue, species: acara, body_id: 1
+			ps = create_ps(pt, "UNKNOWN").tap(&:save!)
+			expect(PetState.next_unlabeled_appearance).to eq ps
+		end
+
+		describe "with multiple unlabeled pet states" do
+			before do
+				# Create three pet types, with ascending order of creation date.
+				@pt1 = create_pt blue,  acara, Date.new(2000)
+				@pt2 = create_pt green, acara, Date.new(2005)
+				@pt3 = create_pt red,   acara, Date.new(2010)
+
+				# Give each a pet state, but created in a different order.
+				@ps1 = create_ps @pt1, "UNKNOWN", Date.new(2020)
+				@ps2 = create_ps @pt2, "UNKNOWN", Date.new(2025)
+				@ps3 = create_ps @pt3, "UNKNOWN", Date.new(2015)
+			end
+
+			it "returns the latest pet type's pet state" do
+				expect(PetState.next_unlabeled_appearance).to eq @ps3
+			end
+
+			it "excludes fully-labeled pet types" do
+				# Label the latest pet state, then see it move to the next.
+				@ps3.update!(pose: "HAPPY_FEM")
+				expect(PetState.next_unlabeled_appearance).to eq @ps2
+			end
+
+			it "excludes labeled pet states" do
+				# Create an older pet state on the latest pet type, than label the
+				# latest pet state, and see it move back to the older one.
+				ps3_a = create_ps @pt3, "UNKNOWN", Date.new(2014)
+				@ps3.update!(pose: "HAPPY_FEM")
+				expect(PetState.next_unlabeled_appearance).to eq ps3_a
+			end
+
+			it "sorts pet states within the latest pet type by newest" do
+				# Create a few pet types on the latest pet type, and see that we get
+				# the latest back.
+				ps3_a = create_ps @pt3, "UNKNOWN", Date.new(2016)
+				ps3_b = create_ps @pt3, "UNKNOWN", Date.new(2017)
+				ps3_c = create_ps @pt3, "UNKNOWN", Date.new(2018)
+				ps3_d = create_ps @pt3, "UNKNOWN", Date.new(2019)
+				expect(PetState.next_unlabeled_appearance).to eq ps3_d
+			end
+
+			it "can find the next after the latest pet state" do
+				expect(PetState.next_unlabeled_appearance(after_id: @ps3.id)).to eq @ps2
+			end
+
+			it "can find the next after any given pet state" do
+				expect(PetState.next_unlabeled_appearance(after_id: @ps2.id)).to eq @ps1
+			end
+
+			it "can find the next after the latest pet state, even within the same pet type" do
+				ps3_a = create_ps @pt3, "UNKNOWN", Date.new(2014)
+				expect(PetState.next_unlabeled_appearance(after_id: @ps3.id)).to eq ps3_a
+			end
+		end
+	end
+end