[webtoons] add 'thumbnails' option (#6468 #7441)

* Update webtoons.py
    Added thumbnail download capability which defaults to false
* Update configuration.rst
    Added documentation for webtoon thumbnail option
* extract thumbnails in GalleryExtractor.assets()
* simplify & fix flake8
* include 'type' in default filenames
* add test
* update docs

---------

Co-authored-by: Mike Fährmann <mike_faehrmann@web.de>

docs/configuration.rst

@@ -5541,6 +5541,17 @@ Description
         | - Set a value to ``false`` to completely remove these extension's ``type`` parameter
         | - Omit an extension to leave its URLs unchanged
 
+extractor.webtoons.thumbnails
+-----------------------------
+Type
+    ``bool``
+Default
+    ``false``
+Description
+    Download the active chapter's ``thumbnail``.
+
+    Useful for creating CBZ archives with actual source thumbnails.
+
 
 extractor.weibo.gifs
 --------------------

docs/gallery-dl.conf

@@ -785,7 +785,8 @@
         {
             "sleep-request": "0.5-1.5",
 
-            "quality": "original"
+            "quality"   : "original",
+            "thumbnails": false
         },
         "weebcentral":
         {

gallery_dl/extractor/webtoons.py

@@ -44,7 +44,7 @@ class WebtoonsEpisodeExtractor(WebtoonsBase, GalleryExtractor):
     """Extractor for an episode on webtoons.com"""
     subcategory = "episode"
     directory_fmt = ("{category}", "{comic}")
-    filename_fmt = "{episode_no}-{num:>02}.{extension}"
+    filename_fmt = "{episode_no}-{num:>02}{type:?-//}.{extension}"
     archive_fmt = "{title_no}_{episode_no}_{num}"
     pattern = (LANG_PATTERN + r"/([^/?#]+)/([^/?#]+)/[^/?#]+)"
                r"/viewer\?([^#'\"]+)")
@@ -59,6 +59,7 @@ class WebtoonsEpisodeExtractor(WebtoonsBase, GalleryExtractor):
         self.title_no = params.get("title_no")
         self.episode_no = params.get("episode_no")
         self.gallery_url = "{}/{}/viewer?{}".format(self.root, path, query)
+        self.thumbnails = self.config("thumbnails", False)
 
     def metadata(self, page):
         extr = text.extract_from(page)
@@ -128,6 +129,13 @@ class WebtoonsEpisodeExtractor(WebtoonsBase, GalleryExtractor):
             results.append((url, None))
         return results
 
+    def assets(self, page):
+        if self.thumbnails:
+            active = text.extr(page, 'class="on ', '</a>')
+            url = text.extr(active, 'data-url="', '"')
+            url = url.replace("://webtoon-phinf.", "://swebtoon-phinf.")
+            return ({"url": url, "type": "thumbnail"},)
+
 
 class WebtoonsComicExtractor(WebtoonsBase, Extractor):
     """Extractor for an entire comic on webtoons.com"""

test/results/webtoons.py

@@ -13,8 +13,8 @@ __tests__ = (
     "#url"     : "https://www.webtoons.com/en/comedy/safely-endangered/ep-572-earth/viewer?title_no=352&episode_no=572",
     "#category": ("", "webtoons", "episode"),
     "#class"   : webtoons.WebtoonsEpisodeExtractor,
-    "#count"       : 5,
-    "#results"     : (
+    "#count"   : 5,
+    "#results" : (
         "https://swebtoon-phinf.pstatic.net/20200513_191/1589322488148XfdRr_PNG/15893224850013525720.png?type=opti",
         "https://swebtoon-phinf.pstatic.net/20200513_143/1589322489499KJLvU_PNG/15893224866183525723.png?type=opti",
         "https://swebtoon-phinf.pstatic.net/20200513_281/15893224881499wbH7_PNG/15893224865073525729.png?type=opti",
@@ -45,6 +45,20 @@ __tests__ = (
     "username"    : "safelyendangered",
 },
 
+{
+    "#url"     : "https://www.webtoons.com/en/comedy/safely-endangered/ep-572-earth/viewer?title_no=352&episode_no=572",
+    "#comment" : "thumbnails (#6468 #7441)",
+    "#class"   : webtoons.WebtoonsEpisodeExtractor,
+    "#options" : {"thumbnails": True},
+    "#range"   : "1",
+    "#results" : "https://swebtoon-phinf.pstatic.net/20200513_37/1589322553469E5p76_PNG/thumb_15893224866533525729.png",
+    "#sha1_content": "e01e70610821df6ece601393eb6fd7d80fc42f9a",
+
+    "count": 5,
+    "num"  : 0,
+    "type" : "thumbnail",
+},
+
 {
     "#url"     : "https://www.webtoons.com/en/challenge/punderworld/happy-earth-day-/viewer?title_no=312584&episode_no=40",
     "#category": ("", "webtoons", "episode"),