[WIP] Add species/color picker for simplified item page preview

Still a lot missing here, like choosing the right default for Baby etc
items, and saving the user's preferences. But it's a start!

app/assets/stylesheets/items/_show.sass

@@ -57,3 +57,14 @@ body.items-show
       img
         width: 100%
         height: 100%
+
+  .species-color-picker
+    .error-icon
+      cursor: help
+      margin-right: .25em
+
+    &[data-is-valid="false"]
+      select
+        border-color: $error-border-color
+        color: $error-color
+

app/controllers/items_controller.rb

@@ -83,15 +83,16 @@ class ItemsController < ApplicationController
           @current_user_quantities = current_user.item_quantities_for(@item)
         end
 
-        @preview_pet_type = PetType.find_by_color_id_and_species_id(
-          Color.find_by_name("Blue"),
-          Species.find_by_name("Acara"),
-        )
+        @selected_preview_pet_type = load_selected_preview_pet_type
+        @preview_pet_type = load_preview_pet_type
+
         @item_layers = @item.appearance_for(
           @preview_pet_type, swf_asset_includes: [:zone]
         ).swf_assets
         @pet_layers = @preview_pet_type.canonical_pet_state.swf_assets.
           includes(:zone)
+
+        @preview_error = validate_preview
       end
 
       format.gif do
@@ -199,6 +200,38 @@ class ItemsController < ApplicationController
       end
   end
 
+  def load_selected_preview_pet_type
+    color_id = params.dig(:preview, :color_id)
+    species_id = params.dig(:preview, :species_id)
+
+    return load_default_preview_pet_type if color_id.nil? || species_id.nil?
+
+    PetType.find_or_initialize_by(color_id:, species_id:)
+  end
+
+  def load_preview_pet_type
+    if @selected_preview_pet_type.persisted?
+      @selected_preview_pet_type
+    else
+      load_default_preview_pet_type
+    end
+  end
+
+  def load_default_preview_pet_type
+    PetType.find_by_color_id_and_species_id(
+      Color.find_by_name("Blue"),
+      Species.find_by_name("Acara"),
+    )
+  end
+
+  def validate_preview
+    if @selected_preview_pet_type.new_record?
+      :pet_type_does_not_exist
+    elsif @item_layers.empty?
+      :no_item_data
+    end
+  end
+  
   def search_error(e)
     @items = []
     @query = params[:q]

app/views/items/show.html.haml

@@ -19,6 +19,21 @@
   %outfit-item-appearance
     = outfit_viewer_layers @item_layers
 
+= form_for item_path(@item), method: :get, class: "species-color-picker",
+  data: {"is-valid": @preview_error.nil?} do |f|
+  - if @preview_error == :pet_type_does_not_exist
+    %span.error-icon{title: "We haven't seen this kind of pet before."} ⚠️
+  - elsif @preview_error == :no_item_data
+    %span.error-icon{title: "We haven't seen this item on this pet before."} ⚠️
+
+  = select_tag "preview[color_id]",
+    options_from_collection_for_select(Color.funny.alphabetical,
+      "id", "human_name", @selected_preview_pet_type.color_id)
+  = select_tag "preview[species_id]",
+    options_from_collection_for_select(Species.alphabetical,
+      "id", "human_name", @selected_preview_pet_type.species_id)
+  = submit_tag "Go", name: nil
+
 - unless @contributors_with_counts.empty?
   #item-contributors
     %header #{t '.contributors.header'}: