sources: rename Sources::Strategies to Source::Extractor.

Rename Sources::Strategies to Source::Extractor. A Source::Extractor
represents a thing that extracts information from a given URL.

app/logical/source/extractor/twitter.rb

@@ -0,0 +1,150 @@
+# frozen_string_literal: true
+
+# @see Source::URL::Twitter
+class Source::Extractor
+  class Twitter < Source::Extractor
+    # List of hashtag suffixes attached to tag other names
+    # Ex: 西住みほ生誕祭2019 should be checked as 西住みほ
+    # The regexes will not match if there is nothing preceding
+    # the pattern to avoid creating empty strings.
+    COMMON_TAG_REGEXES = [
+      /(?<!\A)生誕祭(?:\d*)\z/,
+      /(?<!\A)誕生祭(?:\d*)\z/,
+      /(?<!\A)版もうひとつの深夜の真剣お絵描き60分一本勝負(?:_\d+)?\z/,
+      /(?<!\A)版深夜の真剣お絵描き60分一本勝負(?:_\d+)?\z/,
+      /(?<!\A)版深夜の真剣お絵かき60分一本勝負(?:_\d+)?\z/,
+      /(?<!\A)深夜の真剣お絵描き60分一本勝負(?:_\d+)?\z/,
+      /(?<!\A)版深夜のお絵描き60分一本勝負(?:_\d+)?\z/,
+      /(?<!\A)版真剣お絵描き60分一本勝(?:_\d+)?\z/,
+      /(?<!\A)版お絵描き60分一本勝負(?:_\d+)?\z/
+    ]
+
+    def self.enabled?
+      Danbooru.config.twitter_api_key.present? && Danbooru.config.twitter_api_secret.present?
+    end
+
+    def match?
+      Source::URL::Twitter === parsed_url
+    end
+
+    def image_urls
+      # https://pbs.twimg.com/media/EBGbJe_U8AA4Ekb.jpg:orig
+      if parsed_url.image_url?
+        [parsed_url.full_image_url]
+      elsif api_response.present?
+        api_response.dig(:extended_entities, :media).to_a.map do |media|
+          if media[:type] == "photo"
+            media[:media_url_https] + ":orig"
+          elsif media[:type].in?(["video", "animated_gif"])
+            variants = media.dig(:video_info, :variants)
+            videos = variants.select { |variant| variant[:content_type] == "video/mp4" }
+            video = videos.max_by { |v| v[:bitrate].to_i }
+            video[:url]
+          end
+        end
+      else
+        []
+      end
+    end
+
+    def page_url
+      return nil if status_id.blank? || tag_name.blank?
+      "https://twitter.com/#{tag_name}/status/#{status_id}"
+    end
+
+    def profile_url
+      return nil if tag_name.blank?
+      "https://twitter.com/#{tag_name}"
+    end
+
+    def intent_url
+      user_id = api_response.dig(:user, :id_str)
+      return nil if user_id.blank?
+      "https://twitter.com/intent/user?user_id=#{user_id}"
+    end
+
+    def profile_urls
+      [profile_url, intent_url].compact
+    end
+
+    def tag_name
+      if tag_name_from_url.present?
+        tag_name_from_url
+      elsif api_response.present?
+        api_response.dig(:user, :screen_name)
+      else
+        ""
+      end
+    end
+
+    def artist_name
+      if api_response.present?
+        api_response.dig(:user, :name)
+      else
+        tag_name
+      end
+    end
+
+    def artist_commentary_title
+      ""
+    end
+
+    def artist_commentary_desc
+      api_response[:full_text].to_s
+    end
+
+    def tags
+      api_response.dig(:entities, :hashtags).to_a.map do |hashtag|
+        [hashtag[:text], "https://twitter.com/hashtag/#{hashtag[:text]}"]
+      end
+    end
+
+    def normalize_tag(tag)
+      COMMON_TAG_REGEXES.each do |rg|
+        norm_tag = tag.gsub(rg, "")
+        if norm_tag != tag
+          return norm_tag
+        end
+      end
+      tag
+    end
+
+    def dtext_artist_commentary_desc
+      return "" if artist_commentary_desc.blank?
+
+      url_replacements = api_response.dig(:entities, :urls).to_a.map do |obj|
+        [obj[:url], obj[:expanded_url]]
+      end
+      url_replacements += api_response.dig(:extended_entities, :media).to_a.map do |obj|
+        [obj[:url], ""]
+      end
+      url_replacements = url_replacements.to_h
+
+      desc = artist_commentary_desc.unicode_normalize(:nfkc)
+      desc = CGI.unescapeHTML(desc)
+      desc = desc.gsub(%r{https?://t\.co/[a-zA-Z0-9]+}i, url_replacements)
+      desc = desc.gsub(/#([^[:space:]]+)/, '"#\\1":[https://twitter.com/hashtag/\\1]')
+      desc = desc.gsub(/@([a-zA-Z0-9_]+)/, '"@\\1":[https://twitter.com/\\1]')
+      desc.strip
+    end
+
+    def api_client
+      TwitterApiClient.new(Danbooru.config.twitter_api_key, Danbooru.config.twitter_api_secret)
+    end
+
+    def api_response
+      return {} unless self.class.enabled? && status_id.present?
+      api_client.status(status_id)
+    end
+
+    def status_id
+      parsed_url.status_id || parsed_referer&.status_id
+    end
+
+    def tag_name_from_url
+      parsed_url.username || parsed_referer&.username
+    end
+
+    memoize :api_response
+  end
+end