Refa: more fallbacks for bad citation format (#7710)

### What problem does this PR solve?

More fallbacks for bad citation format

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [x] Refactoring

api/db/services/dialog_service.py

@@ -14,11 +14,11 @@
 #  limitations under the License.
 #
 import binascii
-from datetime import datetime
 import logging
 import re
 import time
 from copy import deepcopy
+from datetime import datetime
 from functools import partial
 from timeit import default_timer as timer
 
@@ -36,8 +36,7 @@ from api.utils import current_timestamp, datetime_format
 from rag.app.resume import forbidden_select_fields4resume
 from rag.app.tag import label_question
 from rag.nlp.search import index_name
-from rag.prompts import chunks_format, citation_prompt, full_question, kb_prompt, keyword_extraction, llm_id2llm_type, message_fit_in, \
-    cross_languages
+from rag.prompts import chunks_format, citation_prompt, cross_languages, full_question, kb_prompt, keyword_extraction, llm_id2llm_type, message_fit_in
 from rag.utils import num_tokens_from_string, rmSpace
 from rag.utils.tavily_conn import Tavily
 
@@ -303,6 +302,39 @@ def chat(dialog, messages, stream=True, **kwargs):
     if "max_tokens" in gen_conf:
         gen_conf["max_tokens"] = min(gen_conf["max_tokens"], max_tokens - used_token_count)
 
+    def repair_bad_citation_formats(answer: str, kbinfos: dict, idx: dict):
+        max_index = len(kbinfos["chunks"])
+
+        def safe_add(i):
+            if 0 <= i < max_index:
+                idx.add(i)
+                return True
+            return False
+
+        def find_and_replace(pattern, group_index=1, repl=lambda i: f"##{i}$$", flags=0):
+            nonlocal answer
+            for match in re.finditer(pattern, answer, flags=flags):
+                try:
+                    i = int(match.group(group_index))
+                    if safe_add(i):
+                        answer = answer.replace(match.group(0), repl(i))
+                except Exception:
+                    continue
+
+        find_and_replace(r"\(\s*ID:\s*(\d+)\s*\)")  # (ID: 12)
+        find_and_replace(r"ID[: ]+(\d+)")  # ID: 12, ID 12
+        find_and_replace(r"\$\$(\d+)\$\$")  # $$12$$
+        find_and_replace(r"\$\[(\d+)\]\$")  # $[12]$
+        find_and_replace(r"\$\$(\d+)\${2,}")  # $$12$$$$
+        find_and_replace(r"\$(\d+)\$")  # $12$
+        find_and_replace(r"#(\d+)\$\$")  # #12$$
+        find_and_replace(r"##(\d+)\$")  # ##12$
+        find_and_replace(r"##(\d+)#{2,}")  # ##12###
+        find_and_replace(r"【(\d+)】")  # 【12】
+        find_and_replace(r"ref\s*(\d+)", flags=re.IGNORECASE)  # ref12, ref 12, REF 12
+
+        return answer, idx
+
     def decorate_answer(answer):
         nonlocal prompt_config, knowledges, kwargs, kbinfos, prompt, retrieval_ts, questions, langfuse_tracer
 
@@ -331,15 +363,7 @@ def chat(dialog, messages, stream=True, **kwargs):
                     if i < len(kbinfos["chunks"]):
                         idx.add(i)
 
-            # handle (ID: 1), ID: 2 etc.
-            for match in re.finditer(r"\(\s*ID:\s*(\d+)\s*\)|ID[: ]+\s*(\d+)", answer):
-                full_match = match.group(0)
-                id = match.group(1) or match.group(2)
-                if id:
-                    i = int(id)
-                    if i < len(kbinfos["chunks"]):
-                        idx.add(i)
-                    answer = answer.replace(full_match, f"##{i}$$")
+            answer, idx = repair_bad_citation_formats(answer, kbinfos, idx)
 
             idx = set([kbinfos["chunks"][int(i)]["doc_id"] for i in idx])
             recall_docs = [d for d in kbinfos["doc_aggs"] if d["doc_id"] in idx]
@@ -599,3 +623,4 @@ def ask(question, kb_ids, tenant_id):
         answer = ans
         yield {"answer": answer, "reference": {}}
     yield decorate_answer(answer)
+