[aryion] add 'tag' extractor (closes #1849)

docs/supportedsites.md

@@ -148,7 +148,7 @@ Consider all sites to be NSFW unless otherwise known.
 <tr>
     <td>Eka's Portal</td>
     <td>https://aryion.com/</td>
-    <td>Galleries, Posts</td>
+    <td>Galleries, Posts, Tag Searches</td>
     <td>Supported</td>
 </tr>
 <tr>

gallery_dl/extractor/aryion.py

@@ -56,10 +56,13 @@ class AryionExtractor(Extractor):
 
     def items(self):
         self.login()
+        data = self.metadata()
 
         for post_id in self.posts():
             post = self._parse_post(post_id)
             if post:
+                if data:
+                    post.update(data)
                 yield Message.Directory, post
                 yield Message.Url, post["url"], post
             elif post is False and self.recursive:
@@ -71,6 +74,9 @@ class AryionExtractor(Extractor):
     def posts(self):
         """Yield relevant post IDs"""
 
+    def metadata(self):
+        """Return general metadata"""
+
     def _pagination(self, url):
         while True:
             page = self.request(url).text
@@ -187,6 +193,25 @@ class AryionGalleryExtractor(AryionExtractor):
             return util.advance(self._pagination(url), self.offset)
 
 
+class AryionTagExtractor(AryionExtractor):
+    """Extractor for tag searches on eka's portal"""
+    subcategory = "tag"
+    directory_fmt = ("{category}", "tags", "{search_tags}")
+    archive_fmt = "t_{search_tags}_{id}"
+    pattern = BASE_PATTERN + r"/tags\.php\?([^#]+)"
+    test = ("https://aryion.com/g4/tags.php?tag=star+wars&p=18", {
+        "count": ">= 5",
+    })
+
+    def metadata(self):
+        return {"search_tags": text.parse_query(self.user).get("tag")}
+
+    def posts(self):
+        url = "{}/g4/tags.php?{}".format(self.root, self.user)
+        self.user = None
+        return self._pagination(url)
+
+
 class AryionPostExtractor(AryionExtractor):
     """Extractor for individual posts on eka's portal"""
     subcategory = "post"