refactor: rewrite facebook item parser for comet bootstrap

packages/core/src/scrapers/facebook.ts

@@ -496,6 +496,80 @@ function findSearchEdges(
   return bestMatch;
 }
 
+interface FacebookMarketplaceItemMatch {
+  item: FacebookMarketplaceItem;
+  score: number;
+  path: string[];
+}
+
+function scoreMarketplaceItemPath(path: string[]): number {
+  let score = 0;
+
+  if (path.includes("payload")) {
+    score += 2;
+  }
+
+  if (path.includes("viewer")) {
+    score += 2;
+  }
+
+  if (path.includes("marketplace_product_details_page")) {
+    score += 6;
+  }
+
+  if (path.includes("target")) {
+    score += 8;
+  }
+
+  if (path.includes("listing")) {
+    score += 6;
+  }
+
+  if (
+    path.some(
+      (segment) =>
+        segment.includes("recommend") || segment.includes("related"),
+    )
+  ) {
+    score -= 10;
+  }
+
+  return score - path.length;
+}
+
+function collectMarketplaceItemCandidates(
+  candidate: unknown,
+  path: string[] = [],
+): FacebookMarketplaceItemMatch[] {
+  if (Array.isArray(candidate)) {
+    return candidate.flatMap((item) => collectMarketplaceItemCandidates(item, path));
+  }
+
+  if (!isRecord(candidate)) {
+    return [];
+  }
+
+  const matches: FacebookMarketplaceItemMatch[] = [];
+
+  if (
+    typeof candidate.id === "string" &&
+    candidate.__typename === "GroupCommerceProductItem" &&
+    typeof candidate.marketplace_listing_title === "string"
+  ) {
+    matches.push({
+      item: candidate as FacebookMarketplaceItem,
+      score: scoreMarketplaceItemPath(path),
+      path,
+    });
+  }
+
+  for (const [key, value] of Object.entries(candidate)) {
+    matches.push(...collectMarketplaceItemCandidates(value, [...path, key]));
+  }
+
+  return matches;
+}
+
 /**
   Extract marketplace search data from Facebook page script tags
 */
@@ -531,139 +605,29 @@ export function extractFacebookMarketplaceData(
 
 /**
    Extract marketplace item details from Facebook item page HTML
-   Updated for 2026 Facebook Marketplace API structure with multiple extraction paths
+   Updated for 2026 Facebook Marketplace bootstrap candidates
 */
 export function extractFacebookItemData(
   htmlString: HTMLString,
 ): FacebookMarketplaceItem | null {
-  const { document } = parseHTML(htmlString);
-  const scripts = document.querySelectorAll("script");
+  const candidates = extractFacebookBootstrapCandidates(htmlString);
+  let bestMatch: FacebookMarketplaceItemMatch | null = null;
 
-  for (const script of scripts) {
-    const scriptText = script.textContent;
-    if (!scriptText) continue;
+  for (const candidate of candidates) {
+    const matches = collectMarketplaceItemCandidates(candidate);
 
-    try {
-      const parsed = JSON.parse(scriptText);
-
-      // Check for the require structure with marketplace product details
-      if (parsed.require && Array.isArray(parsed.require)) {
-        // Try multiple extraction paths discovered from reverse engineering
-        const extractionPaths = [
-          // Path 1: Primary path from current API structure
-          () =>
-            parsed.require[0][3].__bbox.result.data.viewer
-              .marketplace_product_details_page.target,
-          // Path 2: Alternative path with nested require
-          () =>
-            parsed.require[0][3][0].__bbox.require[3][3][1].__bbox.result.data
-              .viewer.marketplace_product_details_page.target,
-          // Path 3: Variation without the [0] index
-          () =>
-            parsed.require[0][3].__bbox.require[3][3][1].__bbox.result.data
-              .viewer.marketplace_product_details_page.target,
-          // Path 4-5: Additional fallback paths for edge cases
-          () =>
-            parsed.require[0][3][1]?.__bbox?.result?.data?.viewer
-              ?.marketplace_product_details_page?.target,
-          () =>
-            parsed.require[0][3][2]?.__bbox?.result?.data?.viewer
-              ?.marketplace_product_details_page?.target,
-        ];
-
-        let pathIndex = 0;
-        for (const getPath of extractionPaths) {
-          try {
-            const targetData = getPath();
-            if (
-              targetData &&
-              typeof targetData === "object" &&
-              targetData.id &&
-              targetData.marketplace_listing_title &&
-              targetData.__typename === "GroupCommerceProductItem"
-            ) {
-              console.log(
-                `Successfully extracted Facebook item data using extraction path ${pathIndex + 1}`,
-              );
-              return targetData as FacebookMarketplaceItem;
-            }
-          } catch {
-            // Path not found or invalid, try next path
-          }
-          pathIndex++;
-        }
-
-        // Fallback: Search recursively for marketplace data in the parsed structure
-        const findMarketplaceData = (
-          obj: unknown,
-          depth = 0,
-          maxDepth = 10,
-        ): FacebookMarketplaceItem | null => {
-          if (depth > maxDepth) return null; // Prevent infinite recursion
-          if (isRecord(obj)) {
-            // Check if this object matches the expected marketplace item structure
-            const candidate = obj as Record<string, unknown>;
-            if (
-              candidate.marketplace_listing_title &&
-              candidate.id &&
-              candidate.__typename === "GroupCommerceProductItem" &&
-              candidate.redacted_description
-            ) {
-              return candidate as unknown as FacebookMarketplaceItem;
-            }
-            // Recursively search nested objects and arrays
-            for (const key in obj) {
-              const value = obj[key];
-              if (isRecord(value) || Array.isArray(value)) {
-                const result = findMarketplaceData(value, depth + 1, maxDepth);
-                if (result) return result;
-              }
-            }
-          } else if (Array.isArray(obj)) {
-            // Search through arrays
-            for (const item of obj) {
-              const result = findMarketplaceData(item, depth + 1, maxDepth);
-              if (result) return result;
-            }
-          }
-          return null;
-        };
-
-        // Search through the entire require structure
-        const recursiveResult = findMarketplaceData(parsed.require);
-        if (recursiveResult) {
-          console.log(
-            "Successfully extracted Facebook item data using recursive search",
-          );
-          return recursiveResult;
-        }
-
-        // Additional search in other potential locations
-        if (
-          parsed.__bbox?.result?.data?.viewer?.marketplace_product_details_page
-            ?.target
-        ) {
-          const bboxData =
-            parsed.__bbox.result.data.viewer.marketplace_product_details_page
-              .target;
-          if (
-            bboxData &&
-            typeof bboxData === "object" &&
-            bboxData.id &&
-            bboxData.marketplace_listing_title &&
-            bboxData.__typename === "GroupCommerceProductItem"
-          ) {
-            console.log(
-              "Successfully extracted Facebook item data from __bbox structure",
-            );
-            return bboxData as FacebookMarketplaceItem;
-          }
-        }
+    for (const match of matches) {
+      if (
+        !bestMatch ||
+        match.score > bestMatch.score ||
+        (match.score === bestMatch.score && match.path.length < bestMatch.path.length)
+      ) {
+        bestMatch = match;
       }
-    } catch {}
+    }
   }
 
-  return null;
+  return bestMatch?.item ?? null;
 }
 
 /**

packages/core/test/facebook-core.test.ts

@@ -369,43 +369,80 @@ describe("Facebook Marketplace Scraper Core Tests", () => {
 
   describe("Data Extraction", () => {
     describe("extractFacebookItemData", () => {
-      test("should extract item data from standard require structure", () => {
-        const mockItemData = {
-          id: "123456",
-          __typename: "GroupCommerceProductItem",
-          marketplace_listing_title: "Test Item",
-          formatted_price: { text: "$100.00" },
-          listing_price: { amount: "100.00", currency: "CAD" },
-          is_live: true,
-        };
-        const mockData = {
-          require: [
-            [
-              null,
-              null,
-              null,
-              {
-                __bbox: {
-                  result: {
-                    data: {
-                      viewer: {
-                        marketplace_product_details_page: {
-                          target: mockItemData,
-                        },
-                      },
+      test("extracts item details from Comet permalink bootstrap candidates", () => {
+        const html = `
+          <html><body>
+            <script>"XCometMarketplacePermalinkController"</script>
+            <script>
+              ${JSON.stringify({
+                payload: {
+                  listing: {
+                    id: "123",
+                    __typename: "GroupCommerceProductItem",
+                    marketplace_listing_title: "Vintage Chair",
+                    formatted_price: { text: "CA$80" },
+                    listing_price: {
+                      amount: "80.00",
+                      currency: "CAD",
+                      amount_with_offset: "80.00",
                     },
+                    redacted_description: { text: "Solid wood chair" },
+                    location_text: { text: "Toronto, ON" },
+                    marketplace_listing_seller: { id: "seller-1", name: "Alex" },
+                    condition: "USED",
+                    is_live: true,
                   },
                 },
-              },
-            ],
-          ],
-        };
-        const html = `<html><body><script>${JSON.stringify(mockData)}</script></body></html>`;
+              })}
+            </script>
+          </body></html>
+        `;
 
         const result = extractFacebookItemData(html);
         expect(result).not.toBeNull();
-        expect(result?.id).toBe("123456");
-        expect(result?.marketplace_listing_title).toBe("Test Item");
+        expect(result?.id).toBe("123");
+        expect(result?.marketplace_listing_title).toBe("Vintage Chair");
+      });
+
+      test("prefers the canonical permalink target over earlier decoy items", () => {
+        const html = `
+          <html><body>
+            <script>"XCometMarketplacePermalinkController"</script>
+            <script>
+              ${JSON.stringify({
+                payload: {
+                  recommendation_units: [
+                    {
+                      listing: {
+                        id: "decoy-1",
+                        __typename: "GroupCommerceProductItem",
+                        marketplace_listing_title: "Recommended Chair",
+                        is_live: true,
+                      },
+                    },
+                  ],
+                  target: {
+                    id: "real-123",
+                    __typename: "GroupCommerceProductItem",
+                    marketplace_listing_title: "Canonical Chair",
+                    formatted_price: { text: "CA$120" },
+                    listing_price: {
+                      amount: "120.00",
+                      currency: "CAD",
+                      amount_with_offset: "120.00",
+                    },
+                    is_live: true,
+                  },
+                },
+              })}
+            </script>
+          </body></html>
+        `;
+
+        const result = extractFacebookItemData(html);
+        expect(result).not.toBeNull();
+        expect(result?.id).toBe("real-123");
+        expect(result?.marketplace_listing_title).toBe("Canonical Chair");
       });
 
       test("should handle missing item data", () => {