artists: clean up artist finding logic.

Rename Artist#find_all_by_url to url_matches and drop previous
url_matches method, along with find_artists and search_for_profile.

Previously find_artists tried to lookup the url, referer url, and profile
url in turn until an artist match was found. This was wasteful, because
the source strategy already knows which url to lookup (usually the profile
url). If that url doesn't find a match, then the artist doesn't exist.

app/logical/sources/strategies/base.rb

@@ -129,6 +129,8 @@ module Sources
         normalize_for_artist_finder.present?
       end
 
+      # The url to use for artist finding purposes. This will be stored in the
+      # artist entry. Normally this will be the profile url.
       def normalize_for_artist_finder
         profile_url || url
       end
@@ -139,8 +141,7 @@ module Sources
       end
 
       def artists
-        url = profile_url.presence || image_url.presence
+        Artist.url_matches(normalize_for_artist_finder)
-        Artist.find_artists(url)
       end
 
       def file_url

app/logical/sources/strategies/twitter.rb

@@ -66,14 +66,6 @@ module Sources::Strategies
       ""
     end
 
-    def artists
-      if profile_url.present?
-        Artist.find_artists(profile_url)
-      else
-        []
-      end
-    end
-
     def artist_name
       return "" if api_response.blank?
       api_response.attrs[:user][:screen_name]

app/models/artist.rb

@@ -148,7 +148,7 @@ class Artist < ApplicationRecord
         %r!\Ahttps?://(?:[a-zA-Z0-9_-]+\.)*#{domain}/\z!i
       end)
 
-      def find_all_by_url(url)
+      def url_matches(url)
         url = ArtistUrl.normalize(url)
         artists = []
 
@@ -163,7 +163,7 @@ class Artist < ApplicationRecord
           break if url =~ SITE_BLACKLIST_REGEXP
         end
 
-        artists.inject({}) {|h, x| h[x.name] = x; h}.values.slice(0, 20)
+        where(id: artists.uniq(&:name).take(20))
       end
     end
 
@@ -456,40 +456,6 @@ class Artist < ApplicationRecord
   end
 
   module SearchMethods
-    def find_artists(url, referer_url = nil)
-      artists = url_matches(url).order("id desc").limit(10)
-
-      if artists.empty? && referer_url.present? && referer_url != url
-        artists = url_matches(referer_url).order("id desc").limit(20)
-      end
-
-      artists
-    rescue PixivApiClient::Error => e
-      []
-    end
-
-    def url_matches(string)
-      matches = find_all_by_url(string).map(&:id)
-
-      if matches.any?
-        where("id in (?)", matches)
-      elsif matches = search_for_profile(string)
-        where("id in (?)", matches)
-      else
-        where("false")
-      end
-    end
-
-    def search_for_profile(url)
-      source = Sources::Strategies.find(url)
-      find_all_by_url(source.profile_url)
-    rescue Net::OpenTimeout, PixivApiClient::Error
-      raise if Rails.env.test?
-      nil
-    rescue Exception
-      nil
-    end
-
     def other_names_match(string)
       if string =~ /\*/ && CurrentUser.is_builder?
         where("artists.other_names ILIKE ? ESCAPE E'\\\\'", string.to_escaped_for_sql_like)

test/unit/artist_test.rb

@@ -154,9 +154,7 @@ class ArtistTest < ActiveSupport::TestCase
     should "resolve ambiguous urls" do
       bobross = FactoryBot.create(:artist, :name => "bob_ross", :url_string => "http://artists.com/bobross/image.jpg")
       bob = FactoryBot.create(:artist, :name => "bob", :url_string => "http://artists.com/bob/image.jpg")
-      matches = Artist.find_all_by_url("http://artists.com/bob/test.jpg")
+      assert_artist_found("bob", "http://artists.com/bob/test.jpg")
-      assert_equal(1, matches.size)
-      assert_equal("bob", matches.first.name)
     end
 
     should "parse urls" do
@@ -190,7 +188,7 @@ class ArtistTest < ActiveSupport::TestCase
     should "ignore pixiv.net/ and pixiv.net/img/ url matches" do
       a1 = FactoryBot.create(:artist, :name => "yomosaka", :url_string => "http://i2.pixiv.net/img18/img/evazion/14901720.png")
       a2 = FactoryBot.create(:artist, :name => "niwatazumi_bf", :url_string => "http://i2.pixiv.net/img18/img/evazion/14901720_big_p0.png")
-      assert_equal([], Artist.find_all_by_url("http://i2.pixiv.net/img28/img/kyang692/35563903.jpg"))
+      assert_artist_not_found("http://i2.pixiv.net/img28/img/kyang692/35563903.jpg")
     end
 
     should "find matches by url" do
@@ -198,11 +196,11 @@ class ArtistTest < ActiveSupport::TestCase
       a2 = FactoryBot.create(:artist, :name => "subway", :url_string => "http://subway.com/x/test.jpg")
       a3 = FactoryBot.create(:artist, :name => "minko", :url_string => "https://minko.com/x/test.jpg")
 
-      assert_equal(["rembrandt"], Artist.find_all_by_url("http://rembrandt.com/x/test.jpg").map(&:name))
+      assert_artist_found("rembrandt", "http://rembrandt.com/x/test.jpg")
-      assert_equal(["rembrandt"], Artist.find_all_by_url("http://rembrandt.com/x/another.jpg").map(&:name))
+      assert_artist_found("rembrandt", "http://rembrandt.com/x/another.jpg")
-      assert_equal([], Artist.find_all_by_url("http://nonexistent.com/test.jpg").map(&:name))
+      assert_artist_not_found("http://nonexistent.com/test.jpg")
-      assert_equal(["minko"], Artist.find_all_by_url("https://minko.com/x/test.jpg").map(&:name))
+      assert_artist_found("minko", "https://minko.com/x/test.jpg")
-      assert_equal(["minko"], Artist.find_all_by_url("http://minko.com/x/test.jpg").map(&:name))
+      assert_artist_found("minko", "http://minko.com/x/test.jpg")
     end
 
     should "be case-insensitive to domains when finding matches by url" do
@@ -212,7 +210,7 @@ class ArtistTest < ActiveSupport::TestCase
 
     should "not find duplicates" do
       FactoryBot.create(:artist, :name => "warhol", :url_string => "http://warhol.com/x/a/image.jpg\nhttp://warhol.com/x/b/image.jpg")
-      assert_equal(["warhol"], Artist.find_all_by_url("http://warhol.com/x/test.jpg").map(&:name))
+      assert_artist_found("warhol", "http://warhol.com/x/test.jpg")
     end
 
     should "not include duplicate urls" do
@@ -222,7 +220,7 @@ class ArtistTest < ActiveSupport::TestCase
 
     should "hide deleted artists" do
       FactoryBot.create(:artist, :name => "warhol", :url_string => "http://warhol.com/a/image.jpg", :is_active => false)
-      assert_equal([], Artist.find_all_by_url("http://warhol.com/a/image.jpg").map(&:name))
+      assert_artist_not_found("http://warhol.com/a/image.jpg")
     end
 
     context "when finding deviantart artists" do