Recover modal preview rendering and card fallbacks

TODO.md

@@ -255,6 +255,21 @@
   - backend debug broadcasts
 
 ## Recent Change Log
+- Date: `2026-03-16`
+- What changed:
+  - Rewired the result modal to consume backend media metadata instead of hard-coded source branches.
+  - Google Video now uses embed-first modal rendering again, with iframe timeout fallback to thumbnail/panel mode.
+  - Search cards now suppress low-value favicon/logo thumbnails and show a neutral “preview unavailable” media state instead of tiny site icons or placeholder-like junk.
+  - Bumped frontend asset version so browsers pick up the new modal logic.
+- Why it changed:
+  - The UI was still rendering Google Video as a static image panel, and Envato/Artgrid cards were surfacing unusable thumbnails that made the results look broken even when metadata existed.
+- How it was verified:
+  - `go test ./...`
+  - `bash scripts/selftest.sh`
+- What is still risky or incomplete:
+  - Browser-level validation was still not fully reproducible here, so iframe timeout behavior and provider-specific rendering quirks still need live confirmation in the deployed UI.
+  - `node` is not installed in this environment, so frontend syntax/build verification is still limited to static inspection plus app boot smoke testing.
+
 - Date: `2026-03-16`
 - What changed:
   - Hardened search result enrichment and recommendation metadata for preview recovery work.

frontend/app.js

@@ -49,6 +49,7 @@ const resultModalThumbnail = document.getElementById("resultModalThumbnail");
 const resultModalGooglePanel = document.getElementById("resultModalGooglePanel");
 const resultModalGoogleImage = document.getElementById("resultModalGoogleImage");
 const resultModalGoogleText = document.getElementById("resultModalGoogleText");
+const resultModalFallbackLabel = document.getElementById("resultModalFallbackLabel");
 const resultModalOpenExternal = document.getElementById("resultModalOpenExternal");
 const resultModalDownload = document.getElementById("resultModalDownload");
 const closeResultModal = document.getElementById("closeResultModal");
@@ -65,6 +66,7 @@ const resultModalReady = Boolean(
   resultModalGooglePanel &&
   resultModalGoogleImage &&
   resultModalGoogleText &&
+  resultModalFallbackLabel &&
   resultModalOpenExternal &&
   resultModalDownload &&
   closeResultModal,
@@ -88,6 +90,41 @@ function proxiedPreviewURL(src) {
   return `/api/preview/stream?url=${encodeURIComponent(src)}`;
 }
 
+function isLowValueThumbnailURL(src) {
+  const lower = String(src || "").toLowerCase();
+  if (!lower) {
+    return true;
+  }
+  return [
+    "favicon",
+    "apple-touch-icon",
+    "/logo",
+    "/icon",
+    "icon.",
+    "logo.",
+    "placehold.co",
+  ].some((token) => lower.includes(token)) ||
+    ((lower.includes("googleusercontent.com") || lower.includes("gstatic.com") || lower.includes("bing.com") || lower.includes("duckduckgo.com")) && !lower.includes("ytimg.com"));
+}
+
+function hasUsableThumbnail(src) {
+  return Boolean(src) && !isLowValueThumbnailURL(src);
+}
+
+function summarizeReason(reason) {
+  const text = String(reason || "").trim();
+  if (!text) {
+    return "";
+  }
+  if (text === "Ranked candidate pending stronger visual evidence.") {
+    return "Preview evidence pending";
+  }
+  if (text === "Fallback due to missing provider preview.") {
+    return "Provider preview missing";
+  }
+  return text;
+}
+
 function setStatus(label, progress) {
   statusLabel.textContent = label;
   statusBar.style.width = `${Math.max(0, Math.min(100, progress))}%`;
@@ -393,13 +430,19 @@ function hideModal(element) {
 }
 
 function buildResultModalEmbedURL(item) {
+  if (item?.embedUrl) {
+    if (item.source === "Google Video" && item.embedUrl.includes("youtube-nocookie.com/embed/")) {
+      return `${item.embedUrl}&origin=${encodeURIComponent(window.location.origin)}`;
+    }
+    return item.embedUrl;
+  }
   if (!item?.link) {
     return "about:blank";
   }
   if (item.source === "Google Video") {
     const videoId = extractYouTubeID(item.link);
     if (videoId) {
-      return `https://www.youtube-nocookie.com/embed/${videoId}?autoplay=1&rel=0&playsinline=1&origin=${encodeURIComponent(window.location.origin)}`;
+      return `https://www.youtube-nocookie.com/embed/${videoId}?autoplay=1&rel=0&playsinline=1&modestbranding=1&enablejsapi=1&origin=${encodeURIComponent(window.location.origin)}`;
     }
   }
   return item.link;
@@ -409,12 +452,14 @@ function resetResultModalMedia() {
   if (!resultModalReady) {
     return;
   }
+  resultModalFrame.onload = null;
   resultModalFrame.src = "about:blank";
   resultModalVideo.pause();
   detachVideoSource(resultModalVideo);
   resultModalThumbnail.removeAttribute("src");
   resultModalGoogleImage.removeAttribute("src");
   resultModalGoogleText.textContent = "";
+  resultModalFallbackLabel.textContent = "Preview Fallback";
   resultModalMediaFrame.style.aspectRatio = "";
   setHidden(resultModalFrame, true, "");
   setHidden(resultModalVideo, true, "");
@@ -444,13 +489,27 @@ function showResultModalThumbnail(src, alt) {
   setHidden(resultModalThumbnail, false, "");
 }
 
-function showResultModalGooglePanel(item) {
+function showResultModalGooglePanel(item, message = "") {
-  resultModalGoogleImage.src = item.thumbnailUrl || PREVIEW_PLACEHOLDER;
+  resultModalFallbackLabel.textContent = item.source || "Preview Fallback";
+  resultModalGoogleImage.src = hasUsableThumbnail(item.thumbnailUrl) ? item.thumbnailUrl : PREVIEW_PLACEHOLDER;
   resultModalGoogleImage.alt = item.title || "";
-  resultModalGoogleText.textContent = item.snippet || item.reason || "YouTube 페이지 열기 또는 Direct Download를 사용할 수 있습니다.";
+  resultModalGoogleText.textContent = message || item.previewBlockedReason || item.snippet || item.reason || "Preview fallback is being shown.";
   setHidden(resultModalGooglePanel, false, "flex");
 }
 
+function fallbackResultModalMedia(item, reason) {
+  logEvent("result:modal:fallback", { title: item.title, source: item.source, reason, mediaMode: item.mediaMode });
+  if (item.previewVideoUrl) {
+    showResultModalVideo(item.previewVideoUrl);
+    return;
+  }
+  if (hasUsableThumbnail(item.thumbnailUrl)) {
+    showResultModalThumbnail(item.thumbnailUrl, item.title || "");
+    return;
+  }
+  showResultModalGooglePanel(item, reason || "Preview fallback is being shown.");
+}
+
 function renderResults(results) {
   searchResults.innerHTML = "";
   if (!results.length) {
@@ -461,15 +520,28 @@ function renderResults(results) {
     const node = cardTemplate.content.firstElementChild.cloneNode(true);
     const image = node.querySelector("img");
     const previewVideo = node.querySelector(".preview-hover");
+    const mediaFallback = node.querySelector(".media-fallback");
     const overlays = node.querySelectorAll(".preview-overlay");
-    image.src = item.thumbnailUrl || PREVIEW_PLACEHOLDER;
+    const usableThumbnail = hasUsableThumbnail(item.thumbnailUrl);
-    image.alt = item.title;
+    if (usableThumbnail) {
+      image.src = item.thumbnailUrl;
+      image.alt = item.title;
+      image.classList.remove("hidden");
+      mediaFallback.classList.add("hidden");
+    } else {
+      image.removeAttribute("src");
+      image.alt = "";
+      image.classList.add("hidden");
+      mediaFallback.classList.remove("hidden");
+      mediaFallback.classList.add("flex");
+      mediaFallback.textContent = item.source === "Envato" || item.source === "Artgrid" ? `${item.source} preview unavailable` : "Preview unavailable";
+    }
     node.querySelector("h3").textContent = item.title;
-    node.querySelector(".result-snippet").textContent = item.reason || item.snippet || item.source || "";
+    node.querySelector(".result-snippet").textContent = summarizeReason(item.reason) || item.snippet || item.source || "";
-    node.querySelector(".result-reason").textContent = item.snippet ? `Source: ${item.snippet}` : "";
+    node.querySelector(".result-reason").textContent = item.snippet ? `Source: ${item.snippet}` : (item.previewBlockedReason || "");
     node.querySelector(".source-badge").textContent = item.source;
     node.addEventListener("click", () => openResultModal(item));
-    previewVideo.poster = item.thumbnailUrl || "";
+    previewVideo.poster = usableThumbnail ? item.thumbnailUrl : "";
     if (item.previewVideoUrl) {
       const mediaArea = node.querySelector(".relative");
       mediaArea.addEventListener("mouseenter", () => {
@@ -521,16 +593,32 @@ function openResultModal(item) {
   activeResultItem = item;
   resultModalTitle.textContent = item.title || "Untitled";
   resultModalSource.textContent = item.source || "";
-  resultModalReason.textContent = item.reason || "AI 노트가 없습니다.";
+  resultModalReason.textContent = summarizeReason(item.reason) || "AI 노트가 없습니다.";
   resultModalSnippet.textContent = item.snippet || "원본 페이지에서 사용할 수 있는 설명이 없습니다.";
   resultModalOpenExternal.href = item.link || "#";
   const canDirectDownload = item.source === "Google Video" && item.link;
   resultModalDownload.classList.toggle("hidden", !canDirectDownload);
   resetResultModalMedia();
-  if (item.source === "Google Video") {
+  const embedURL = buildResultModalEmbedURL(item);
-    showResultModalGooglePanel(item);
+  const fallbackReason = item.previewBlockedReason || "Embedded view was unavailable, switched to fallback preview.";
+  if (item.mediaMode === "embed" && embedURL && embedURL !== "about:blank") {
+    showResultModalFrame(embedURL);
+    const timeout = window.setTimeout(() => {
+      logEvent("result:modal:iframe_timeout", { title: item.title, source: item.source, embedURL });
+      if (activeResultItem?.link === item.link) {
+        resetResultModalMedia();
+        fallbackResultModalMedia(item, fallbackReason);
+      }
+    }, item.source === "Google Video" ? 5000 : 2000);
+    resultModalFrame.onload = () => {
+      window.clearTimeout(timeout);
+    };
+  } else if (item.mediaMode === "preview_video" && item.previewVideoUrl) {
+    showResultModalVideo(item.previewVideoUrl);
+  } else if (item.mediaMode === "thumbnail" && hasUsableThumbnail(item.thumbnailUrl)) {
+    showResultModalThumbnail(item.thumbnailUrl, item.title || "");
   } else {
-    showResultModalFrame(item.link || "about:blank");
+    fallbackResultModalMedia(item, fallbackReason);
   }
   showModal(resultModal);
   logEvent("result:modal:open", { title: item.title, source: item.source, link: item.link });

frontend/index.html

@@ -172,7 +172,7 @@
                   <img id="resultModalGoogleImage" class="aspect-video w-full object-cover" alt="" />
                 </div>
                 <div class="flex flex-col gap-3 rounded-2xl border border-white/10 bg-white/[0.04] p-5 text-left">
-                  <p class="text-xs uppercase tracking-[0.25em] text-zinc-500">Google Video</p>
+                  <p id="resultModalFallbackLabel" class="text-xs uppercase tracking-[0.25em] text-zinc-500">Preview Fallback</p>
                   <p id="resultModalGoogleText" class="text-sm leading-7 text-zinc-200"></p>
                 </div>
               </div>
@@ -202,6 +202,9 @@
         <div class="relative aspect-video overflow-hidden bg-zinc-900">
           <img class="h-full w-full object-cover transition duration-500 group-hover:scale-105" alt="" />
           <video class="preview-hover absolute inset-0 hidden h-full w-full object-cover" muted loop playsinline preload="none"></video>
+          <div class="media-fallback absolute inset-0 hidden items-center justify-center bg-[radial-gradient(circle_at_top,#2b3342,transparent_60%),linear-gradient(180deg,#111827,#05070b)] p-5 text-center text-xs uppercase tracking-[0.24em] text-zinc-300">
+            Preview unavailable
+          </div>
           <div class="preview-overlay absolute left-3 top-3 rounded-full border border-white/20 bg-black/60 px-3 py-1 text-[11px] uppercase tracking-[0.25em] text-white">AI Recommended</div>
           <div class="source-badge preview-overlay absolute bottom-3 left-3 rounded-full bg-white px-3 py-1 text-[11px] font-medium uppercase tracking-[0.2em] text-black"></div>
         </div>
@@ -213,6 +216,6 @@
       </button>
     </template>
 
-    <script src="/app.js?v=20260316g" defer></script>
+    <script src="/app.js?v=20260316h" defer></script>
   </body>
 </html>