Add Phase 5: link-card fragments, oEmbed endpoints, OG meta

- fetch_fragment_batch() for N+1 avoidance with per-key Redis cache - link-card fragment handlers in blog, market, events, federation (single + batch mode) - link_card.html templates per app with content-specific previews - shared/infrastructure/oembed.py: build_oembed_response, build_og_meta, build_oembed_link_tag - GET /oembed routes on blog, market, events - og_meta + oembed_link rendering in base template <head> - INTERNAL_URL_ARTDAG in docker-compose.yml for cross-stack fragment fetches Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-24 21:44:11 +00:00
parent 4d7f8cfea2
commit b3d853ad35
15 changed files with 601 additions and 0 deletions
--- a/shared/infrastructure/fragments.py
+++ b/shared/infrastructure/fragments.py
@@ -134,6 +134,115 @@ async def fetch_fragments(
    )))


+async def fetch_fragment_batch(
+    app_name: str,
+    fragment_type: str,
+    *,
+    keys: list[str],
+    params: dict | None = None,
+    ttl: int = 30,
+    timeout: float = _DEFAULT_TIMEOUT,
+    required: bool = True,
+) -> dict[str, str]:
+    """Fetch a batched fragment keyed by multiple identifiers.
+
+    The provider receives *keys* as a comma-separated ``keys`` query param
+    and returns HTML with ``<!-- fragment:{key} -->`` comment markers
+    delimiting each entry.  Returns ``dict[key, html]`` with ``""`` for
+    missing keys.
+
+    Individual results are cached in Redis per key.
+    """
+    if _is_fragment_request() or not keys:
+        return {k: "" for k in keys}
+
+    redis = _get_redis()
+    results: dict[str, str] = {}
+    missing: list[str] = []
+
+    # Build base suffix from extra params
+    psuffix = ""
+    if params:
+        sorted_items = sorted(params.items())
+        psuffix = ":" + "&".join(f"{k}={v}" for k, v in sorted_items)
+
+    # Check Redis for individually cached keys
+    for key in keys:
+        cache_key = f"frag:{app_name}:{fragment_type}:{key}{psuffix}"
+        if redis and ttl > 0:
+            try:
+                cached = await redis.get(cache_key)
+                if cached is not None:
+                    results[key] = cached.decode() if isinstance(cached, bytes) else cached
+                    continue
+            except Exception:
+                pass
+        missing.append(key)
+
+    if not missing:
+        return results
+
+    # Fetch missing keys in one request
+    fetch_params = dict(params or {})
+    fetch_params["keys"] = ",".join(missing)
+
+    try:
+        html = await fetch_fragment(
+            app_name, fragment_type, params=fetch_params,
+            timeout=timeout, required=required,
+        )
+    except FragmentError:
+        for key in missing:
+            results.setdefault(key, "")
+        if required:
+            raise
+        return results
+
+    # Parse response by <!-- fragment:{key} --> markers
+    parsed = _parse_fragment_markers(html, missing)
+    for key in missing:
+        value = parsed.get(key, "")
+        results[key] = value
+        # Cache individual results
+        if redis and ttl > 0:
+            cache_key = f"frag:{app_name}:{fragment_type}:{key}{psuffix}"
+            try:
+                await redis.set(cache_key, value.encode(), ex=ttl)
+            except Exception:
+                pass
+
+    return results
+
+
+def _parse_fragment_markers(html: str, keys: list[str]) -> dict[str, str]:
+    """Split batched HTML by ``<!-- fragment:{key} -->`` comment markers."""
+    result: dict[str, str] = {}
+    marker_prefix = "<!-- fragment:"
+    marker_suffix = " -->"
+
+    for i, key in enumerate(keys):
+        start_marker = f"{marker_prefix}{key}{marker_suffix}"
+        start_idx = html.find(start_marker)
+        if start_idx == -1:
+            result[key] = ""
+            continue
+        content_start = start_idx + len(start_marker)
+
+        # Find next marker or end of string
+        next_marker_idx = len(html)
+        for other_key in keys:
+            if other_key == key:
+                continue
+            other_marker = f"{marker_prefix}{other_key}{marker_suffix}"
+            idx = html.find(other_marker, content_start)
+            if idx != -1 and idx < next_marker_idx:
+                next_marker_idx = idx
+
+        result[key] = html[content_start:next_marker_idx].strip()
+
+    return result
+
+
 async def fetch_fragment_cached(
    app_name: str,
    fragment_type: str,