feat: extract individual Facebook marketplace items

src/facebook.ts

@@ -611,7 +611,108 @@ function formatCentsToCurrency(
 }
 
 /**
-  Parse Facebook marketplace search results into ListingDetails[]
+   Extract marketplace item details from Facebook item page HTML
+   Updated for 2026 Facebook Marketplace API structure with multiple extraction paths
+*/
+function extractFacebookItemData(htmlString: HTMLString): FacebookMarketplaceItem | null {
+	const { document } = parseHTML(htmlString);
+	const scripts = document.querySelectorAll("script");
+
+	for (const script of scripts) {
+		const scriptText = script.textContent;
+		if (!scriptText) continue;
+
+		try {
+			const parsed = JSON.parse(scriptText);
+
+			// Check for the 2026 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
+						if (obj.marketplace_listing_title && obj.id &&
+							obj.__typename === 'GroupCommerceProductItem' &&
+							obj.redacted_description) {
+							return obj 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;
+					}
+				}
+			}
+		} catch (error) {
+			// Log parsing errors for debugging but continue to next script
+			console.debug(`Failed to parse script for Facebook item data: ${error}`);
+		}
+	}
+
+	return null;
+}
+
+/**
+   Parse Facebook marketplace search results into ListingDetails[]
 */
 function parseFacebookAds(ads: FacebookAdNode[]): ListingDetails[] {
 	const results: ListingDetails[] = [];