add duplicate check to toctree_fix function (useblocks#92)

* add duplicate check to toctree_fix function

* correct placement of duplicate headline fix

* replace .strip with .replace

* reformatting of duplicate check

sphinx_simplepdf/builders/simplepdf.py

@@ -1,3 +1,4 @@
+from collections import Counter
 import os
 import re
 from typing import Any, Dict
@@ -172,6 +173,37 @@ def _toctree_fix(self, html):
             for link in links:
                 link["href"] = link["href"].replace(f"{self.app.config.root_doc}.html", "")
 
+            # search for duplicates
+            counts = dict(Counter([str(x).split(">")[0] for x in links]))
+            duplicates = {key: value for key, value in counts.items() if value > 1}
+
+            if duplicates:
+                print("found duplicate references in toctree attempting to fix")
+
+            for text, counter in duplicates.items():
+
+                ref = re.findall("href=\"#.*\"", str(text))
+
+                # clean href data for searching
+                cleaned_ref_toc = ref[0].replace("href=\"", "").replace("\"", "") # "#target"
+                cleaned_ref_target = ref[0].replace("href=\"#", "").replace("\"", "") # "target"
+
+                occurences = soup.find_all('section', attrs={"id": cleaned_ref_target})
+
+                # rename duplicate references, relies on fact -> order in toc is order of occurence in document
+                replace_counter = 0
+
+                for link in links:
+                    if link["href"] == cleaned_ref_toc:
+                        # edit reference in table of content
+                        link["href"] = link["href"] + "-" + str(replace_counter + 1)
+
+                        # edit target reference
+                        occurences[replace_counter]["id"] = occurences[replace_counter]["id"] + "-" + str(
+                            replace_counter + 1)
+
+                        replace_counter += 1
+
         for heading_tag in ["h1", "h2"]:
             headings = soup.find_all(heading_tag, class_="")
             for number, heading in enumerate(headings):