feat(note): 在笔记开头添加来源链接功能

backend/app/utils/note_helper.py

@@ -1,9 +1,39 @@
 import re
 
+
+def prepend_source_link(markdown: str | None, source_url: str) -> str | None:
+    """
+    在笔记开头添加来源链接；若首个非空行已包含来源链接，则更新该行并避免重复。
+    """
+    if markdown is None:
+        return None
+
+    source = (source_url or "").strip()
+    if not source:
+        return markdown
+
+    header = f"> 来源链接：{source}"
+    lines = markdown.splitlines()
+    first_non_empty_idx = None
+    for idx, line in enumerate(lines):
+        if line.strip():
+            first_non_empty_idx = idx
+            break
+
+    if first_non_empty_idx is not None:
+        first_line = lines[first_non_empty_idx].strip()
+        if first_line.startswith("> 来源链接：") or first_line.startswith("来源链接："):
+            lines[first_non_empty_idx] = header
+            return "\n".join(lines)
+
+    if markdown.strip():
+        return f"{header}\n\n{markdown}"
+    return header
+
+
 def replace_content_markers(markdown: str, video_id: str, platform: str = 'bilibili') -> str:
     """
-    替换 *Content-04:16*、Content-04:16 或 Content-[04:16] 为超链接
-    目标格式：- [04:16](https://www.bilibili.com/video/BVxxx?t=256#t=04:16)
+    替换 *Content-04:16*、Content-04:16 或 Content-[04:16] 为超链接，跳转到对应平台视频的时间位置
     """
     # 匹配三种形式：*Content-04:16*、Content-04:16、Content-[04:16]
     pattern = r"(?:\*?)Content-(?:\[(\d{2}):(\d{2})\]|(\d{2}):(\d{2}))"
@@ -14,28 +44,23 @@ def replace_content_markers(markdown: str, video_id: str, platform: str = 'bilib
         mm = match.group(1) or match.group(3)
         ss = match.group(2) or match.group(4)
         total_seconds = int(mm) * 60 + int(ss)
-        time_str = f"{mm}:{ss}"
 
         if platform == 'bilibili':
-            # 处理多 P 情况，如果是 BV123_p3 转换为 BV123?p=3
-            actual_video_id = video_id.replace("_p", "?p=")
-            
-            # 判断连接符是 ? 还是 & (如果 video_id 里已经有了 ?p=，则时间参数用 &t=)
-            connector = "&t=" if "?" in actual_video_id else "?t="
-            
-            # 拼接最终 URL，并在末尾加上 #t=MM:SS 锚点
-            url = f"https://www.bilibili.com/video/{actual_video_id}{connector}{total_seconds}#t={time_str}"
-            return f"- [{time_str}]({url})"
-
+            video_id = video_id.replace("_p", "?p=")
+            url = f"https://www.bilibili.com/video/{video_id}&t={total_seconds}"
+            parsed_video_id = safe_video_id.replace("_p", "?p=")
+            url = f"https://www.bilibili.com/video/{parsed_video_id}&t={total_seconds}"
         elif platform == 'youtube':
             url = f"https://www.youtube.com/watch?v={video_id}&t={total_seconds}s"
-            return f"- [{time_str}]({url})"
-
+            url = f"https://www.youtube.com/watch?v={safe_video_id}&t={total_seconds}s"
         elif platform == 'douyin':
             url = f"https://www.douyin.com/video/{video_id}"
-            return f"[原片 @ {time_str}]({url})"
-            
+            url = f"https://www.douyin.com/video/{safe_video_id}"
+            return f"[原片 @ {mm}:{ss}]({url})"
         else:
-            return f"({time_str})"
+            return f"({mm}:{ss})"
+
+        return f"[原片 @ {mm}:{ss}]({url})"
 
     return re.sub(pattern, replacer, markdown)
+