1 files changed, 61 insertions, 0 deletions
diff --git a/web_utils.py b/web_utils.py
new file mode 100644
index 0000000..91561b5
--- /dev/null
+++ b/web_utils.py
@@ -0,0 +1,61 @@
+import urllib.request
+import subprocess
+import re
+from typing import Dict, Union
+from dataclasses import dataclass
+
+
+@dataclass
+class FetchSuccess:
+    """Successful fetch result containing the markdown content."""
+
+    content: str
+
+
+@dataclass
+class FetchError:
+    """Failed fetch result containing the error message."""
+
+    error: str
+
+
+FetchResult = Union[FetchSuccess, FetchError]
+
+# Memoization cache for web pages
+_cache: Dict[str, FetchResult] = {}
+
+
+def html_to_markdown(html: str) -> str:
+    """Converts HTML to markdown using pandoc with GFM format."""
+    try:
+        # Use gfm (GitHub Flavored Markdown) for better compatibility and robust conversion
+        process = subprocess.run(
+            ["pandoc", "-f", "html", "-t", "gfm", "-o", "-"],
+            input=html,
+            capture_output=True,
+            text=True,
+            check=True,
+            encoding="utf-8",
+        )
+        return process.stdout.strip()
+    except subprocess.CalledProcessError as e:
+        raise RuntimeError(f"Pandoc error: {e}")
+    except Exception as e:
+        raise RuntimeError(f"Unexpected error during markdown conversion: {e}")
+
+
+def fetch_and_markdownify(url: str) -> FetchResult:
+    """Fetches a web page and transforms it to markdown, with memoization."""
+    if url in _cache:
+        return _cache[url]
+
+    try:
+        req = urllib.request.Request(url, headers={"User-Agent": "Mozilla/5.0"})
+        with urllib.request.urlopen(req, timeout=10) as response:
+            html = response.read().decode("utf-8")
+            markdown = html_to_markdown(html)
+            res = FetchSuccess(content=markdown)
+            _cache[url] = res
+            return res
+    except Exception as e:
+        return FetchError(error=str(e))