add additional meta tags for seo

app/logical/downloads/file.rb

@@ -22,6 +22,8 @@ module Downloads
     end
 
     def is_cloudflare?
+      return false if ENV["SKIP_CLOUDFLARE_CHECK"]
+
       Cache.get("is_cloudflare:#{file_url.origin}", 4.hours) do
         res = HTTParty.head(file_url, httparty_options)
         raise Error.new("HTTP error code: #{res.code} #{res.message}") unless res.success?

app/logical/post_sets/base.rb

@@ -36,6 +36,10 @@ module PostSets
       false
     end
 
+    def best_post
+      nil
+    end
+
     def presenter
       raise NotImplementedError
     end

app/logical/post_sets/post.rb

@@ -26,7 +26,7 @@ module PostSets
     end
 
     def has_wiki?
-      is_single_tag? && ::WikiPage.titled(tag_string).exists? && wiki_page.visible?
+      is_single_tag? && ::WikiPage.titled(tag_string).exists? && wiki_page.visible? && wiki_page.body.present?
     end
 
     def has_blank_wiki?
@@ -184,5 +184,10 @@ module PostSets
     def presenter
       @presenter ||= ::PostSetPresenters::Post.new(self)
     end
+
+    def best_post
+      # be smarter about this in the future
+      posts[0]
+    end
   end
 end

app/views/posts/index.html.erb

@@ -65,22 +65,12 @@
 <% end %>
 
 <%= content_for(:html_header) do %>
-  <link href="<%= posts_path(:format => 'atom', :tags => params[:tags]) %>" rel="alternate" title="ATOM" type="application/atom+xml" />
-  <%#= tag.link rel: "prefetch", href: next_page_url, as: "html", crossorigin: "use-credentials" %>
+  <%= tag.link href: posts_path(format: "atom", tags: params[:tags]), rel: "alternate", title: "ATOM", type: "application/atom+xml" %>
+  <%= tag.link rel: "prefetch", href: next_page_url, as: "html", crossorigin: "use-credentials" %>
   <%= tag.link rel: "next", href: next_page_url %>
   <% if prev_page_url %>
     <%= tag.link rel: "prev", href: prev_page_url %>
   <% end %>
-  <% if @post_set.has_wiki? %>
-    <meta name="description" content="<%= strip_dtext(@post_set.wiki_page.presenter.excerpt) %>">
-  <% else %>
-    <meta name="description" content="<%= Danbooru.config.description %>">
-  <% end %>
   <%= missed_post_search_count_js %>
-  <% if @post_set.hide_from_crawler? %>
-    <meta name="robots" content="nofollow,noindex">
-  <% end %>
-  <% if @post_set.has_explicit? %>
-    <meta name="rating" content="adult">
-  <% end %>
+  <%= render "posts/partials/index/seo_meta_tags" %>
 <% end %>

app/views/posts/partials/index/_seo_meta_tags.html.erb

@@ -0,0 +1,49 @@
+<% if @post_set.has_wiki? %>
+  <% strip_dtext(@post_set.wiki_page.presenter.excerpt).tap do |title| %>
+    <%= tag.meta name: "og:title", content: title %>
+    <%= tag.meta name: "twitter:title", content: title %>
+  <% end %>
+<% elsif @post_set.tag_string.present? %>
+  <% "#{@post_set.humanized_tag_string} - #{Danbooru.config.app_name}".tap do |title| %>
+    <%= tag.meta name: "og:title", content: title %>
+    <%= tag.meta name: "twitter:title", content: title %>
+  <% end %>
+<% else %>
+  <% Danbooru.config.description.tap do |title| %>
+    <%= tag.meta name: "og:title", content: title %>
+    <%= tag.meta name: "twitter:title", content: title %>
+  <% end %>
+<% end %>
+
+<% if @post_set.hide_from_crawler? %>
+  <meta name="robots" content="nofollow,noindex">
+<% end %>
+
+<% if @post_set.has_explicit? %>
+  <meta name="rating" content="adult">
+<% end %>
+
+<%= tag.meta name: "canonical", content: posts_url(tags: params[:tags], host: Danbooru.config.domain) %>
+
+<% if params[:tags].present? %>
+  <% "Find the best art of #{params[:tags].tr('_', ' ').titleize} on #{Danbooru.config.app_name}".tap do |desc| %>
+    <%= tag.meta name: "description", content: desc %>
+    <%= tag.meta name: "og:description", content: desc %>
+    <%= tag.meta name: "twitter:description", content: desc %>
+  <% end %>
+<% else %>
+  <% Danbooru.config.description.tap do |desc| %>
+    <%= tag.meta name: "description", content: desc %>
+    <%= tag.meta name: "og:description", content: desc %>
+    <%= tag.meta name: "twitter:description", content: desc %>
+  <% end %>
+<% end %>
+
+<%= tag.meta name: "og:type", content: "website" %>
+<%= tag.meta name: "og:site", content: Danbooru.config.app_name %>
+
+<% if @post_set.best_post.present? %>
+  <%= tag.meta name: "twitter:image", content: @post_set.best_post.file_url %>
+  <%= tag.meta name: "og:image", content: @post_set.best_post.file_url %>
+  <%= tag.meta name: "twitter:card", content: "summary_large_image" %>
+<% end %>