自动同步: 2026-03-18 02:10

skills/kb_workflow/pipeline/link_parser.py

@@ -0,0 +1,181 @@
+"""Link Parser module
+
+Provides unified URL parsing for various content platforms.
+Supports Bilibili (video, article) and Zhihu (answer, zhuanlan) URLs.
+"""
+
+import re
+from dataclasses import dataclass, field
+from typing import Optional
+
+import requests
+
+from kb_workflow.pipeline.retry import retry_on_network_error
+
+
+@dataclass
+class ParsedLink:
+    """Represents a parsed link with platform and content information
+
+    Attributes:
+        platform: Platform name (bilibili, zhihu)
+        content_type: Content type (video, article, answer, zhuanlan)
+        content_id: Unique content identifier
+        original_url: Original URL provided by user
+        resolved_url: Resolved URL after short link expansion (defaults to original_url)
+    """
+    platform: str
+    content_type: str
+    content_id: str
+    original_url: str
+    resolved_url: str = field(default="")
+
+    def __post_init__(self):
+        """Set resolved_url to original_url if not provided"""
+        if not self.resolved_url:
+            self.resolved_url = self.original_url
+
+
+class LinkParser:
+    """Unified URL parser for multiple platforms
+
+    Parses URLs from Bilibili and Zhihu, extracting platform, content type,
+    and content ID. Supports short link resolution for b23.tv URLs.
+    """
+
+    # Bilibili patterns
+    BILIBILI_VIDEO_PATTERN = re.compile(
+        r'https?://(?:www\.)?bilibili\.com/video/(BV[a-zA-Z0-9]+)',
+        re.IGNORECASE
+    )
+    BILIBILI_ARTICLE_PATTERN = re.compile(
+        r'https?://(?:www\.)?bilibili\.com/(?:read|article)/(cv[a-zA-Z0-9]+)',
+        re.IGNORECASE
+    )
+
+    # Zhihu patterns
+    ZHIHU_ANSWER_PATTERN = re.compile(
+        r'https?://(?:www\.)?zhihu\.com/question/\d+/answer/(\d+)',
+        re.IGNORECASE
+    )
+    ZHIHU_ZHUANLAN_PATTERN = re.compile(
+        r'https?://zhuanlan\.zhihu\.com/p/(\d+)',
+        re.IGNORECASE
+    )
+
+    # Short link patterns
+    B23_TV_PATTERN = re.compile(
+        r'https?://(?:www\.)?b23\.tv/([a-zA-Z0-9]+)',
+        re.IGNORECASE
+    )
+
+    # Timeout for short link resolution
+    SHORT_LINK_TIMEOUT = 10
+
+    @retry_on_network_error
+    def _resolve_shortlink(self, url: str) -> Optional[str]:
+        """Resolve short link to its final URL
+
+        Uses HTTP HEAD request with redirects to get the final URL.
+
+        Args:
+            url: Short link URL to resolve
+
+        Returns:
+            Final URL after redirects, or None if resolution failed
+        """
+        try:
+            response = requests.head(
+                url,
+                allow_redirects=True,
+                timeout=self.SHORT_LINK_TIMEOUT
+            )
+            if response.status_code == 200:
+                return response.url
+            return None
+        except (requests.RequestException, OSError):
+            return None
+
+    def parse(self, url: str) -> Optional[ParsedLink]:
+        """Parse a URL and extract platform, content type, and ID
+
+        Args:
+            url: URL to parse
+
+        Returns:
+            ParsedLink with extracted information, or None if URL is not recognized
+        """
+        if not url or not isinstance(url, str):
+            return None
+
+        url = url.strip()
+
+        # Try b23.tv short link first
+        if self.B23_TV_PATTERN.match(url):
+            resolved_url = self._resolve_shortlink(url)
+            if resolved_url:
+                # Recursively parse the resolved URL
+                result = self._parse_standard_url(resolved_url)
+                if result:
+                    result.original_url = url
+                    result.resolved_url = resolved_url
+                return result
+            return None
+
+        return self._parse_standard_url(url)
+
+    def _parse_standard_url(self, url: str) -> Optional[ParsedLink]:
+        """Parse a standard (non-short) URL
+
+        Args:
+            url: URL to parse
+
+        Returns:
+            ParsedLink with extracted information, or None if URL is not recognized
+        """
+        # Try Bilibili video
+        match = self.BILIBILI_VIDEO_PATTERN.match(url)
+        if match:
+            return ParsedLink(
+                platform="bilibili",
+                content_type="video",
+                content_id=match.group(1),
+                original_url=url,
+                resolved_url=url
+            )
+
+        # Try Bilibili article
+        match = self.BILIBILI_ARTICLE_PATTERN.match(url)
+        if match:
+            return ParsedLink(
+                platform="bilibili",
+                content_type="article",
+                content_id=match.group(1),
+                original_url=url,
+                resolved_url=url
+            )
+
+        # Try Zhihu answer
+        match = self.ZHIHU_ANSWER_PATTERN.match(url)
+        if match:
+            return ParsedLink(
+                platform="zhihu",
+                content_type="answer",
+                content_id=match.group(1),
+                original_url=url,
+                resolved_url=url
+            )
+
+        # Try Zhihu zhuanlan
+        match = self.ZHIHU_ZHUANLAN_PATTERN.match(url)
+        if match:
+            return ParsedLink(
+                platform="zhihu",
+                content_type="zhuanlan",
+                content_id=match.group(1),
+                original_url=url,
+                resolved_url=url
+            )
+
+        # URL not recognized
+        return None