Remove hundreds of unnecessary queries from /alt-styles page!

I think the Rails query cache handled these anyway? But `SwfAsset` has
a `before_save` hook that checks its zone's info, and
`SwfAsset.preload_manifests` saves all the assets, on the assumption
that saving is a no-op when the record didn't change anyway. And it
basically is!

But I figure that, now that I'm realizing hooks exist, simply not
attempting to save unchanged records is probably a better
representation of what we intend to do. So I'm fixing it like that!

Another potential fix would be to preload the zones for these assets,
but I think that confuses the intent too much; the method itself isn't
using the zones, it's just a weird incidental thing that a save hook
happens to use. (Would probably be better to refactor this old save
hook into a different situation altogether, but that's for another
time!)

app/models/alt_style.rb

@@ -1,3 +1,5 @@
+require "addressable/template"
+
 class AltStyle < ApplicationRecord
   belongs_to :species
   belongs_to :color
@@ -6,6 +8,10 @@ class AltStyle < ApplicationRecord
   has_many :swf_assets, through: :parent_swf_asset_relationships
   has_many :contributions, as: :contributed, inverse_of: :contributed
 
+  validates :body_id, presence: true
+
+  before_create :infer_series_name
+
   scope :matching_name, ->(series_name, color_name, species_name) {
     color = Color.find_by_name!(color_name)
     species = Species.find_by_name!(species_name)
@@ -35,11 +41,20 @@ class AltStyle < ApplicationRecord
     "#{series_name} #{color.human_name}"
   end
 
+  THUMBNAIL_URL_TEMPLATE = Addressable::Template.new(
+    "https://images.neopets.com/items/{series}_{color}_{species}.gif"
+  )
+  DEFAULT_THUMBNAIL_URL = "https://images.neopets.com/items/mall_bg_circle.gif"
   def thumbnail_url
-    # HACK: Just assume this is a Nostalgic Alt Style, and that the thumbnail
-    # is named reliably!
-    "https://images.neopets.com/items/nostalgic_" +
-      "#{color.name.gsub(/\s+/, '').downcase}_#{species.name.downcase}.gif"
+    return DEFAULT_THUMBNAIL_URL unless has_real_series_name?
+
+    # HACK: We're assuming this is the format long-term! But if it changes, we
+    # may need to add it as a database field instead.
+    THUMBNAIL_URL_TEMPLATE.expand(
+      series: series_name.gsub(/\s+/, '').downcase,
+      color: color.name.gsub(/\s+/, '').downcase,
+      species: species.name.gsub(/\s+/, '').downcase,
+    ).to_s
   end
 
   def preview_image_url
@@ -63,6 +78,19 @@ class AltStyle < ApplicationRecord
     end
   end
 
+  # Until the end of 2024, assume new alt styles are from the "Nostalgic"
+  # series. That way, we can stop having to manually label them all as they
+  # come out and get modeled (TNT is prolific rn!), but we aren't gonna get too
+  # greedy and forget about this and use Nostalgic for some far-future thing,
+  # in ways that will certainly be fixable but would also be confusing and
+  # embarrassing.
+  NOSTALGIC_FINAL_DAY = Date.new(2024, 12, 31)
+  def infer_series_name
+    if !has_real_series_name? && Date.today <= NOSTALGIC_FINAL_DAY
+      self.series_name = "Nostalgic"
+    end
+  end
+
   # For convenience in the console!
   def self.find_by_name(color_name, species_name)
     color = Color.find_by_name(color_name)

app/models/swf_asset.rb

@@ -338,7 +338,7 @@ class SwfAsset < ApplicationRecord
     end
 
     SwfAsset.transaction do
-      swf_assets.each(&:save!)
+      swf_assets.select(&:changed?).each(&:save!)
     end
   end
 

app/views/alt_styles/index.html.haml

@@ -9,14 +9,9 @@
 	name on the homepage! Thank you! 💖
 
 %p
-	Also, heads-up: Style tokens are pretty different from normal wearables, so
-	we haven't decided how to bring them into the customizer yet! Whatever we do,
-	it'll be a bit tricky and new 😅❗️
-
-%p
-	Also, second heads-up: Because our system can only collect "item data" for
-	normal wearable items, there's not a great way for us to get style tokens
-	onto tradelists… this may change someday, but probably not soon, sorry!
+	Also, heads-up: Because our system can only collect "item data" for normal
+	wearable items, there's not a great way for us to get style tokens onto
+	tradelists… this may change someday, but probably not soon, sorry!
 
 - @alt_styles.group_by(&:species).each do |species, species_styles|
 	%h2.alt-styles-header= species.human_name