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/nijie.rb

@@ -0,0 +1,174 @@
+# frozen_string_literal: true
+
+# @see Source::URL::Nijie
+module Source
+  class Extractor
+    class Nijie < Source::Extractor
+      def self.enabled?
+        Danbooru.config.nijie_login.present? && Danbooru.config.nijie_password.present?
+      end
+
+      def match?
+        Source::URL::Nijie === parsed_url
+      end
+
+      def image_urls
+        if parsed_url.image_url?
+          [parsed_url.full_image_url]
+        else
+          image_urls_from_page
+        end
+      end
+
+      def image_urls_from_page
+        if doujin?
+          images = page&.search("#dojin_left .left img").to_a.pluck("src")
+          images += page&.search("#dojin_diff img.mozamoza").to_a.pluck("data-original")
+        else
+          images = page&.search("div#gallery a > .mozamoza").to_a.pluck("src")
+        end
+
+        images.map { |img| Source::URL.parse("https:#{img}").full_image_url }
+      end
+
+      def page_url
+        return nil if illust_id.blank?
+        "https://nijie.info/view.php?id=#{illust_id}"
+      end
+
+      def profile_url
+        return nil if artist_id.blank?
+        "https://nijie.info/members.php?id=#{artist_id}"
+      end
+
+      def artist_name
+        if doujin?
+          page&.at("#dojin_left .right a[href*='members.php?id=']")&.text
+        else
+          page&.at("a.name")&.text
+        end
+      end
+
+      def artist_commentary_title
+        if doujin?
+          page&.search("#dojin_text p.title")&.text
+        else
+          page&.search("h2.illust_title")&.text
+        end
+      end
+
+      def artist_commentary_desc
+        if doujin?
+          page&.search("#dojin_text p:not(.title)")&.to_html
+        else
+          page&.search('#illust_text > p')&.to_html
+        end
+      end
+
+      def tags
+        links = page&.search("div#view-tag a") || []
+
+        search_links = links.select do |node|
+          node["href"] =~ /search(?:_dojin)?\.php/
+        end
+
+        search_links.map do |node|
+          [node.inner_text, "https://nijie.info" + node.attr("href")]
+        end
+      end
+
+      def tag_name
+        "nijie" + artist_id.to_s
+      end
+
+      def self.to_dtext(text)
+        text = text.to_s.gsub(/\r\n|\r/, "<br>")
+
+        dtext = DText.from_html(text) do |element|
+          if element.name == "a" && element["href"]&.start_with?("/jump.php")
+            element["href"] = element.text
+          end
+        end
+
+        dtext.strip
+      end
+
+      def illust_id
+        parsed_url.work_id || parsed_referer&.work_id
+      end
+
+      def artist_id_from_url
+        parsed_url.user_id || parsed_referer&.user_id
+      end
+
+      def artist_id_from_page
+        page&.search("a.name")&.first&.attr("href")&.match(/members\.php\?id=(\d+)/) { $1.to_i }
+      end
+
+      def artist_id
+        artist_id_from_url || artist_id_from_page
+      end
+
+      def doujin?
+        page&.at("#dojin_left").present?
+      end
+
+      def page
+        return nil if page_url.blank? || client.blank?
+
+        response = client.cache(1.minute).get(page_url)
+
+        if response.status != 200 || response.parse.search("#login_illust").present?
+          clear_cached_session_cookie!
+        else
+          response.parse
+        end
+      end
+      memoize :page
+
+      def client
+        return nil if cached_session_cookie.nil?
+        http.cookies(R18: 1, **cached_session_cookie)
+      end
+
+      def http
+        super.timeout(60).use(retriable: { max_retries: 20 })
+      end
+
+      # { "NIJIEIJIEID" => "5ca3f816c0c1f3e647940b08b8ab7a45", "nijie_tok" => <long-base64-string> }
+      def cached_session_cookie
+        Cache.get("nijie-session-cookie", 60.minutes, skip_nil: true) do
+          session_cookie
+        end
+      end
+
+      def clear_cached_session_cookie!
+        flush_cache # clear memoized session cookie
+        Cache.delete("nijie-session-cookie")
+      end
+
+      def session_cookie
+        login_page = http.get("https://nijie.info/login.php").parse
+
+        form = {
+          email: Danbooru.config.nijie_login,
+          password: Danbooru.config.nijie_password,
+          url: login_page.at("input[name='url']")&.fetch("value"),
+          save: "on",
+          ticket: ""
+        }
+
+        response = http.post("https://nijie.info/login_int.php", form: form)
+
+        if response.status == 200
+          response.cookies.cookies.map { |cookie| [cookie.name, cookie.value] }.to_h
+        else
+          DanbooruLogger.info "Nijie login failed (#{url}, #{response.status})"
+          nil
+        end
+      end
+
+      memoize :client, :cached_session_cookie
+    end
+  end
+end