[mangadex] update parameter handling for API requests

- move common parameters into '_pagination()'
- add 'ratings' (#1908) and 'api-parameters' options

docs/configuration.rst

@@ -1403,6 +1403,19 @@ Description
     The server to use for API requests.
 
 
+extractor.mangadex.api-parameters
+---------------------------------
+Type
+    ``object``
+Example
+    ``{"order[updatedAt]": "desc"}``
+Description
+    Additional query parameters to send when fetching manga chapters.
+
+    (See `/manga/{id}/feed <https://api.mangadex.org/docs.html#operation/get-manga-id-feed>`_
+    and `/user/follows/manga/feed <https://api.mangadex.org/docs.html#operation/get-user-follows-manga-feed>`_)
+
+
 extractor.mangadex.lang
 -----------------------
 Type
@@ -1424,6 +1437,16 @@ Description
     Provide ``artist``, ``author``, and ``group`` metadata fields.
 
 
+extractor.mangadex.ratings
+--------------------------
+Type
+    ``list`` of ``strings``
+Default
+    ``["safe", "suggestive", "erotica", "pornographic"]``
+Description
+    List of acceptable content ratings for returned chapters.
+
+
 extractor.mastodon.reblogs
 --------------------------
 Type

gallery_dl/extractor/mangadex.py

@@ -209,22 +209,15 @@ class MangadexAPI():
         return self._call("/manga/" + uuid)["data"]
 
     def manga_feed(self, uuid):
-        config = self.extractor.config
-        order = "desc" if config("chapter-reverse") else "asc"
+        order = "desc" if self.extractor.config("chapter-reverse") else "asc"
         params = {
-            "order[volume]"       : order,
-            "order[chapter]"      : order,
-            "translatedLanguage[]": config("lang"),
-            "contentRating[]"     : [
-                "safe", "suggestive", "erotica", "pornographic"],
+            "order[volume]" : order,
+            "order[chapter]": order,
         }
         return self._pagination("/manga/" + uuid + "/feed", params)
 
     def user_follows_manga_feed(self):
-        params = {
-            "order[publishAt]"    : "desc",
-            "translatedLanguage[]": self.extractor.config("lang"),
-        }
+        params = {"order[publishAt]": "desc"}
         return self._pagination("/user/follows/manga/feed", params)
 
     def authenticate(self):
@@ -275,8 +268,20 @@ class MangadexAPI():
     def _pagination(self, endpoint, params=None):
         if params is None:
             params = {}
+
+        config = self.extractor.config
+        ratings = config("ratings")
+        if ratings is None:
+            ratings = ("safe", "suggestive", "erotica", "pornographic")
+
+        params["contentRating[]"] = ratings
+        params["translatedLanguage[]"] = config("lang")
         params["offset"] = 0
 
+        api_params = config("api-parameters")
+        if api_params:
+            params.update(api_params)
+
         while True:
             data = self._call(endpoint, params)
             yield from data["data"]