deviantart: revert to 7f482dc35b

that's the latest commit made to deviantart files before switching from
the developer API to the Javascript backend from the new "Eclipse"
frontend.
This is necessary because it's basically impossible to download posts
now with the JS backend without being logged in, i.e. having the cookies
from a logged in user, which can't be used for very long even if
exporting them from a browser. You would have to save the cookies
deviantart sends you back via the "Set-Cookie" header in a database
somewhere in addition to the other added complexity.

also
* (temporarily) replace HttpartyCache with HTTParty as it's long been
  removed
* fix one case of "last argument as keyword parameter"
* change repository url (5d1a1cc87e)
* remove self-explanatory comment

app/logical/deviant_art_api_client.rb

@@ -1,59 +1,73 @@
-# https://github.com/danbooru/danbooru/issues/4144
+# Authentication is via OAuth2 with the client credentials grant. Register a
+# new app at https://www.deviantart.com/developers/ to obtain a client_id and
+# client_secret. The app doesn't need to be published.
 #
 # API requests must send a user agent and must use gzip compression, otherwise
 # 403 errors will be returned.
+#
+# API calls operate on UUIDs. The deviation ID in the URL is not the UUID. UUIDs
+# are obtained by scraping the HTML page for the <meta property="da:appurl"> element.
+#
+# * https://www.deviantart.com/developers/
+# * https://www.deviantart.com/developers/authentication
+# * https://www.deviantart.com/developers/errors
+# * https://www.deviantart.com/developers/http/v1/20160316
 
-DeviantArtApiClient = Struct.new(:deviation_id) do
-  extend Memoist
+class DeviantArtApiClient
+  class Error < StandardError; end
+  BASE_URL = "https://www.deviantart.com/api/v1/oauth2"
 
-  def extended_fetch
-    params = { deviationid: deviation_id, type: "art", include_session: false }
-    get("https://www.deviantart.com/_napi/da-deviation/shared_api/deviation/extended_fetch", params: params)
+  attr_reader :client_id, :client_secret, :httparty_options
+
+  def initialize(client_id, client_secret, httparty_options = {})
+    @client_id, @client_secret, @httparty_options = client_id, client_secret, httparty_options
   end
 
-  def extended_fetch_json
-    JSON.parse(extended_fetch.body).with_indifferent_access
+  # https://www.deviantart.com/developers/http/v1/20160316/deviation_single/bcc296bdf3b5e40636825a942a514816
+  def deviation(uuid)
+    request("/deviation/#{uuid}")
   end
 
-  def download_url
-    url = extended_fetch_json.dig(:deviation, :extended, :download, :url)
-    response = get(url)
-    response.headers[:location]
+  # https://www.deviantart.com/developers/http/v1/20160316/deviation_download/bed6982b88949bdb08b52cd6763fcafd
+  def download(uuid, mature_content: "1")
+    request("/deviation/download/#{uuid}", mature_content: mature_content)
   end
 
-  def get(url, retries: 1, **options)
-    response = http.cookies(cookies).get(url, **options)
+  # https://www.deviantart.com/developers/http/v1/20160316/deviation_metadata/7824fc14d6fba6acbacca1cf38c24158
+  def metadata(*uuids, mature_content: "1", ext_submission: "1", ext_camera: "1", ext_stats: "1")
+    params = {
+      deviationids: uuids.flatten,
+      mature_content: mature_content,
+      ext_submission: ext_submission,
+      ext_camera: ext_camera,
+      ext_stats: ext_stats,
+    }
 
-    new_cookies = response.cookies.cookies.map { |cookie| { cookie.name => cookie.value } }.reduce(&:merge)
-    new_cookies = new_cookies.slice(:userinfo, :auth, :authsecure)
-    if new_cookies.present?
-      DanbooruLogger.info("DeviantArt: updating cookies", url: url, new_cookies: new_cookies, old_cookies: cookies)
-      self.cookies = new_cookies
-    end
-
-    # If the old auth cookie expired we may get a 404 with a new auth cookie
-    # set. Try again with the new cookie.
-    if response.code == 404 && retries > 0
-      DanbooruLogger.info("DeviantArt: retrying", url: url, cookies: cookies)
-      response = get(url, retries: retries - 1, **options)
-    end
-
-    response
+    request("/deviation/metadata", **params)
   end
 
-  def cookies
-    Cache.get("deviantart_cookies", 10.years.to_i) do
-      JSON.parse(Danbooru.config.deviantart_cookies)
-    end
+  def request(url, **params)
+    options = {
+      base_uri: BASE_URL,
+      params: { access_token: access_token.token, **params },
+      headers: { "Accept-Encoding" => "gzip" },
+      format: :plain,
+    }
+
+    body, code = HTTParty.get(url, **options)
+     JSON.parse(Zlib.gunzip(body), symbolize_names: true)
   end
 
-  def cookies=(new_cookies)
-    Cache.put("deviantart_cookies", new_cookies, 10.years.to_i)
+  def oauth
+    OAuth2::Client.new(client_id, client_secret, site: "https://www.deviantart.com", token_url: "/oauth2/token")
   end
 
-  def http
-    HTTP.use(:auto_inflate).headers(Danbooru.config.http_headers.merge("Accept-Encoding" => "gzip"))
+  def access_token
+    @access_token = oauth.client_credentials.get_token if @access_token.nil? || @access_token.expired?
+    @access_token
   end
 
-  memoize :extended_fetch, :extended_fetch_json, :download_url
+  def access_token=(hash)
+    @access_token = OAuth2::AccessToken.from_hash(oauth, hash)
+  end
 end