Add fits and not_fits back to item search

Some fun stuff here to figure out how to API this out well, but I'm pretty pleased with where it ended up!

app/models/color.rb

@@ -6,6 +6,11 @@ class Color < ActiveRecord::Base
   scope :standard, -> { where(:standard => true) }
   scope :nonstandard, -> { where(:standard => false) }
   scope :funny, -> { order(:prank) unless pranks_funny? }
+  scope :matching_name, ->(name, locale = I18n.locale) {
+    ct = Color::Translation.arel_table
+    joins(:translations).where(ct[:locale].eq(locale)).
+      where(ct[:name].matches(sanitize_sql_like(name)))
+  }
 
   validates :name, presence: true
   
@@ -33,4 +38,10 @@ class Color < ActiveRecord::Base
     now = Time.now.in_time_zone('Pacific Time (US & Canada)')
     now.month == 4 && now.day == 1
   end
+
+  # TODO: Copied from modern Rails source, can delete once we're there!
+  def self.sanitize_sql_like(string, escape_character = "\\")
+    pattern = Regexp.union(escape_character, "%", "_")
+    string.gsub(pattern) { |x| [escape_character, x].join }
+  end
 end

app/models/item.rb

@@ -48,12 +48,12 @@ class Item < ActiveRecord::Base
   scope :name_includes, ->(value, locale = I18n.locale) {
     it = Item::Translation.arel_table
     Item.joins(:translations).where(it[:locale].eq(locale)).
-      where(it[:name].matches('%' + Item.sanitize_sql_like(value) + '%'))
+      where(it[:name].matches('%' + sanitize_sql_like(value) + '%'))
   }
   scope :name_excludes, ->(value, locale = I18n.locale) {
     it = Item::Translation.arel_table
     Item.joins(:translations).where(it[:locale].eq(locale)).
-      where(it[:name].matches('%' + Item.sanitize_sql_like(value) + '%').not)
+      where(it[:name].matches('%' + sanitize_sql_like(value) + '%').not)
   }
   scope :is_nc, -> {
     i = Item.arel_table
@@ -67,23 +67,20 @@ class Item < ActiveRecord::Base
     it = Item::Translation.arel_table
     joins(:translations).where(it[:locale].eq('en')).
       where('description LIKE ?',
-        '%' + Item.sanitize_sql_like(PAINTBRUSH_SET_DESCRIPTION) + '%')
+        '%' + sanitize_sql_like(PAINTBRUSH_SET_DESCRIPTION) + '%')
   }
   scope :is_not_pb, -> {
     it = Item::Translation.arel_table
     joins(:translations).where(it[:locale].eq('en')).
       where('description NOT LIKE ?',
-        '%' + Item.sanitize_sql_like(PAINTBRUSH_SET_DESCRIPTION) + '%')
+        '%' + sanitize_sql_like(PAINTBRUSH_SET_DESCRIPTION) + '%')
   }
   scope :occupies, ->(zone_label, locale = I18n.locale) {
     zone_ids = Zone.matching_label(zone_label, locale).map(&:id)
-    i = Item.arel_table
     sa = SwfAsset.arel_table
     joins(:swf_assets).where(sa[:zone_id].in(zone_ids)).distinct
   }
   scope :not_occupies, ->(zone_label, locale = I18n.locale) {
-    # TODO: This is pretty slow! But I imagine it's uncommon so that's probably
-    # fine in practice? Querying for "has NO records matching X" is hard!
     zone_ids = Zone.matching_label(zone_label, locale).map(&:id)
     i = Item.arel_table
     sa = SwfAsset.arel_table
@@ -107,6 +104,30 @@ class Item < ActiveRecord::Base
     condition = zone_ids.map { '(SUBSTR(zones_restrict, ?, 1) = "1")' }.join(' OR ')
     where("NOT (#{condition})", *zone_ids)
   }
+  scope :fits, ->(body_id) {
+    sa = SwfAsset.arel_table
+    joins(:swf_assets).where(sa[:body_id].eq(body_id)).distinct
+  }
+  scope :not_fits, ->(body_id) {
+    i = Item.arel_table
+    sa = SwfAsset.arel_table
+    # Querying for "has NO swf_assets matching these body IDs" is trickier than
+    # the positive case! To do it, we GROUP_CONCAT the body_ids together for
+    # each item, then use FIND_IN_SET to search the result for the body ID,
+    # and assert that it must not find a match. (This is uhh, not exactly fast,
+    # so it helps to have other tighter conditions applied first!)
+    #
+    # TODO: I feel like this could also be solved with a LEFT JOIN, idk if that
+    # performs any better? In Rails 5+ `left_outer_joins` is built in so!
+    #
+    # NOTE: The `fits` and `not_fits` counts don't perfectly add up to the
+    # total number of items, 5 items aren't accounted for? I'm not going to
+    # bother looking into this, but one thing I notice is items with no assets
+    # somehow would not match either scope in this impl (but LEFT JOIN would!)
+    joins(:swf_assets).group(i[:id]).
+      having('FIND_IN_SET(?, GROUP_CONCAT(body_id)) = 0', body_id).
+      distinct
+  }
 
   def closeted?
     @owned || @wanted

app/models/item/search/query.rb

@@ -46,6 +46,18 @@ class Item
             filters << (is_positive ?
               Filter.restricts(value, locale) :
               Filter.not_restricts(value, locale))
+          when 'fits'
+            color_name, species_name = value.split('-')
+            begin
+              pet_type = PetType.matching_name(color_name, species_name, locale).first!
+            rescue ActiveRecord::RecordNotFound
+              message = I18n.translate('items.search.errors.not_found.pet_type',
+                name1: color_name.capitalize, name2: species_name.capitalize)
+              raise Item::Search::Error, message
+            end
+            filters << (is_positive ?
+              Filter.fits(pet_type.body_id, color_name, species_name) :
+              Filter.not_fits(pet_type.body_id, color_name, species_name))
           when 'is'
             case value
             when 'nc'
@@ -82,9 +94,9 @@ class Item
     # A Filter is basically a wrapper for an Item scope, with extra info about
     # how to convert it into a search query string.
     class Filter
-      def initialize(query, text)
+      def initialize(query, text_fn)
         @query = query
-        @text = text
+        @text_fn = text_fn
       end
 
       def to_query
@@ -92,7 +104,7 @@ class Item
       end
 
       def to_s
-        @text
+        @text_fn.call
       end
 
       def inspect
@@ -125,6 +137,20 @@ class Item
         self.new Item.not_restricts(value, locale), "-restricts:#{value}"
       end
 
+      def self.fits(body_id, color_name, species_name)
+        # NOTE: Some color syntaxes are weird, like `fits:"polka dot-aisha"`!
+        value = "#{color_name.downcase}-#{species_name.downcase}"
+        value = '"' + value + '"' if value.include? ' '
+        self.new Item.fits(body_id), "fits:#{value}"
+      end
+
+      def self.not_fits(body_id, color_name, species_name)
+        # NOTE: Some color syntaxes are weird, like `fits:"polka dot-aisha"`!
+        value = "#{color_name.downcase}-#{species_name.downcase}"
+        value = '"' + value + '"' if value.include? ' '
+        self.new Item.not_fits(body_id), "-fits:#{value}"
+      end
+
       def self.is_nc
         self.new Item.is_nc, 'is:nc'
       end
@@ -148,6 +174,16 @@ class Item
       def self.is_not_pb
         self.new Item.is_not_pb, '-is:pb'
       end
+
+      private
+
+      def self.build_fits_filter_text(color_name, species_name)
+        # NOTE: Colors like "Polka Dot" must be written as
+        # `fits:"polka dot-aisha"`.
+        value = "#{color_name.downcase}-#{species_name.downcase}"
+        value = '"' + value + '"' if value.include? ' '
+        "fits:#{value}"
+      end
     end
   end
 end

app/models/pet_type.rb

@@ -21,6 +21,12 @@ class PetType < ActiveRecord::Base
   
   scope :includes_child_translations,
     -> { includes({:color => :translations, :species => :translations}) }
+  
+  scope :matching_name, ->(color_name, species_name, locale = I18n.locale) {
+    color = Color.matching_name(color_name, locale).first!
+    species = Species.matching_name(species_name, locale).first!
+    where(color_id: color.id, species_id: species.id)
+  }
 
   def self.special_color_or_basic(special_color)
     color_ids = special_color ? [special_color.id] : Color.basic.select([:id]).map(&:id)

app/models/species.rb

@@ -2,6 +2,12 @@ class Species < ActiveRecord::Base
   translates :name
   
   scope :alphabetical, -> { with_translations(I18n.locale).order(Species::Translation.arel_table[:name]) }
+
+  scope :matching_name, ->(name, locale = I18n.locale) {
+    st = Species::Translation.arel_table
+    joins(:translations).where(st[:locale].eq(locale)).
+      where(st[:name].matches(sanitize_sql_like(name)))
+  }
   
   def as_json(options={})
     {:id => id, :name => human_name}
@@ -14,4 +20,10 @@ class Species < ActiveRecord::Base
       I18n.translate('species.default_human_name')
     end
   end
+
+  # TODO: Copied from modern Rails source, can delete once we're there!
+  def self.sanitize_sql_like(string, escape_character = "\\")
+    pattern = Regexp.union(escape_character, "%", "_")
+    string.gsub(pattern) { |x| [escape_character, x].join }
+  end
 end