Refactor revision logic to make more straightforward

Use groupby so we don't have to deal with edge cases and compare
revisions directly.

Signed-off-by: Will Beason <willbeason@gmail.com>

wikiq

@@ -10,6 +10,7 @@ import os.path
 import re
 from datetime import datetime, timezone
 from io import TextIOWrapper
+from itertools import groupby
 
 from subprocess import Popen, PIPE
 from collections import deque
@@ -93,6 +94,10 @@ class WikiqPage:
         self.mwpage = page
         self.__revisions = self.rev_list()
 
+    @staticmethod
+    def user_text(rev) -> str | None:
+        return None if rev.deleted.user else rev.user.text
+
     def rev_list(self):
         # Outline for how we want to handle collapse_user=True
         # iteration   rev.user   prev_rev.user   add prev_rev?
@@ -108,27 +113,13 @@ class WikiqPage:
                 yield rev
             return
 
-        collapsed_revs = 1
-        prev_rev = next(self.mwpage)
-        prev_rev.collapsed_revs = collapsed_revs
-
-        for rev in self.mwpage:
-            # yield if this is the last edit in a seq by a user and reset
-            # also yield if we don't know who the user is
-
-            if rev.deleted.user or prev_rev.deleted.user or rev.user.text != prev_rev.user.text:
-                yield prev_rev
-                collapsed_revs = 1
-                rev.collapsed_revs = collapsed_revs
-            else:
-                # Otherwise, collapse revision.
-                collapsed_revs += 1
-                rev.collapsed_revs = collapsed_revs
-
-            prev_rev = rev
-
-        # also yield the final time
-        yield prev_rev
+        for _, revs in groupby(self.mwpage, self.user_text):
+            # All revisions are either from the same user, or this is a single
+            # revision where the user is missing.
+            revs = list(revs)
+            rev = revs[-1]
+            rev.collapsed_revs = len(revs)
+            yield rev
 
     def __iter__(self):
         return self.__revisions