Initial commit

app/converter.py

@@ -0,0 +1,103 @@
+import json
+import os
+import re
+from functools import lru_cache
+from html.parser import HTMLParser
+from pathlib import Path
+from urllib.error import HTTPError, URLError
+from urllib.request import Request, urlopen
+
+API_URL = "https://api.github.com/markdown"
+API_VERSION = "2022-11-28"
+TEMPLATE_PATH = Path(__file__).resolve().parent.parent / "template.html"
+
+
+class FirstHeadingParser(HTMLParser):
+    def __init__(self) -> None:
+        super().__init__()
+        self._capture = False
+        self._done = False
+        self._parts: list[str] = []
+
+    def handle_starttag(self, tag: str, attrs) -> None:
+        if self._done:
+            return
+        if tag in {"h1", "h2", "h3", "h4", "h5", "h6"}:
+            self._capture = True
+
+    def handle_endtag(self, tag: str) -> None:
+        if self._capture and tag in {"h1", "h2", "h3", "h4", "h5", "h6"}:
+            self._capture = False
+            self._done = True
+
+    def handle_data(self, data: str) -> None:
+        if self._capture and not self._done:
+            self._parts.append(data)
+
+    def title(self) -> str:
+        return "".join(self._parts).strip()
+
+
+def render_markdown(markdown_text: str) -> str:
+    payload = json.dumps({"text": markdown_text}).encode("utf-8")
+    headers = {
+        "Accept": "text/html",
+        "Content-Type": "application/json",
+        "User-Agent": "md-to-html-service",
+        "X-GitHub-Api-Version": API_VERSION,
+    }
+
+    github_token = os.getenv("GITHUB_TOKEN")
+    if github_token:
+        headers["Authorization"] = f"Bearer {github_token}"
+
+    request = Request(API_URL, data=payload, headers=headers, method="POST")
+    try:
+        with urlopen(request, timeout=30) as response:
+            return response.read().decode("utf-8")
+    except HTTPError as exc:
+        error_body = exc.read().decode("utf-8", errors="replace")
+        raise RuntimeError(
+            f"GitHub API error: {exc.code} {exc.reason}\n{error_body}"
+        ) from exc
+    except URLError as exc:
+        raise RuntimeError(f"Failed to reach GitHub API: {exc.reason}") from exc
+
+
+def extract_title(html_text: str, fallback: str) -> str:
+    parser = FirstHeadingParser()
+    parser.feed(html_text)
+    return parser.title() or fallback
+
+
+def apply_template(template_text: str, html_text: str, title: str) -> str:
+    updated = re.sub(
+        r"<title>.*?</title>",
+        f"<title>{title}</title>",
+        template_text,
+        flags=re.DOTALL,
+    )
+    output_lines = []
+    inserted = False
+    html_lines = [f"        {line}" if line else "" for line in html_text.splitlines()]
+    for line in updated.splitlines():
+        if not inserted and "Markdown -->" in line:
+            output_lines.extend(html_lines)
+            inserted = True
+            continue
+        output_lines.append(line)
+    if not inserted:
+        raise RuntimeError("Template placeholder not found.")
+    return "\n".join(output_lines) + "\n"
+
+
+@lru_cache(maxsize=1)
+def load_template_text() -> str:
+    return TEMPLATE_PATH.read_text(encoding="utf-8")
+
+
+def convert(markdown_text: str, fallback_title: str = "Document") -> str:
+    html_text = render_markdown(markdown_text)
+    title = extract_title(html_text, fallback_title)
+    template_text = load_template_text()
+    return apply_template(template_text, html_text, title)