feat: scrape listing details from Kijiji ads

src/kijiji.ts

@@ -13,12 +13,31 @@ interface ApolloSearchState {
 	};
 }
 
+interface ApolloListingState {
+	[key: string]: any;
+}
+
+function formatCentsToCurrency(num: number | string, locale = "en-US") {
+	if (typeof num === "string") num = parseInt(num);
+	const numberInDollars = num / 100;
+
+	const formatter = new Intl.NumberFormat(locale, {
+		minimumFractionDigits: 2,
+		maximumFractionDigits: 2,
+		useGrouping: true,
+	});
+
+	return formatter.format(numberInDollars);
+}
+
 const searchQuery = "playstation 5";
+const REQUESTS_PER_SECOND = 1;
+const DELAY_MS = 1000 / REQUESTS_PER_SECOND;
 
 // const exampleSearchHTML = Bun.file("./example-kijiji-search.html");
 // const exampleSearchHTMLData = await exampleSearchHTML.text();
 
-function extractSearchListingsFromNextData(htmlString: string) {
+function parseSearch(htmlString: string) {
 	const { document } = parseHTML(htmlString);
 	const nextData = document.getElementById("__NEXT_DATA__");
 
@@ -44,18 +63,15 @@ function extractSearchListingsFromNextData(htmlString: string) {
 			}
 		}
 
-		const searchListings: (SearchListing | undefined)[] = listingsKeys.map(
-			(key) => {
-				const listing = apolloState[key];
-				if (!listing) return undefined;
-				return {
-					listingLink: listing.url,
-					name: listing.title,
-				};
-			},
-		);
+		const searchListings: SearchListing[] = listingsKeys.map((key) => {
+			const listing = apolloState[key];
+			return {
+				listingLink: listing!.url,
+				name: listing!.title,
+			};
+		});
 
-		console.log(searchListings);
+		// console.log(searchListings);
 
 		return searchListings;
 	} catch (error) {
@@ -64,8 +80,9 @@ function extractSearchListingsFromNextData(htmlString: string) {
 	}
 }
 
-const makeKijijiRequest = async (url: string): Promise<string> => {
-	const request = await fetch(url, {
+const makeKijijiRequest = async <T>(url: string): Promise<T> => {
+	console.log(`Making a request at ${new Date()}`);
+	const response = await fetch(url, {
 		headers: {
 			accept:
 				"text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7",
@@ -85,9 +102,129 @@ const makeKijijiRequest = async (url: string): Promise<string> => {
 		method: "GET",
 	});
 
-	return await request.text();
+	const rateLimitRemaining = response.headers.get("X-RateLimit-Remaining");
+	const rateLimitReset = response.headers.get("X-RateLimit-Reset");
+
+	if (rateLimitRemaining !== null && rateLimitReset !== null) {
+		console.log(
+			`Rate limit remaining: ${rateLimitRemaining}, Reset in: ${rateLimitReset} seconds`,
+		);
+	}
+
+	const data: T = (await response.text()) as T;
+	return data;
 };
 
-// https://www.kijiji.ca/b-canada/${searchQuery}/k0l0?dc=true&view=list
+async function delay(ms: number): Promise<void> {
+	return new Promise((resolve) => setTimeout(resolve, ms));
+}
 
-// extractSearchListingsFromNextData(await kijijiRequest.text());
+// const exampleListing = await Bun.file("./examples/apollo_listing.json").json();
+// const exampleListingApolloState =
+// 	exampleListing.props.pageProps.__APOLLO_STATE__;
+
+const parseListing = (htmlString: string) => {
+	const { document } = parseHTML(htmlString);
+	const nextData = document.getElementById("__NEXT_DATA__");
+
+	if (!nextData) {
+		console.error("Could not find __NEXT_DATA__ script element.");
+		return [];
+	}
+
+	if (!nextData.textContent) {
+		console.error("__NEXT_DATA__ element is empty!");
+		return [];
+	}
+	const jsonData = JSON.parse(nextData.textContent);
+	const apolloState: ApolloListingState =
+		jsonData.props.pageProps.__APOLLO_STATE__;
+
+	const getListingId = (apolloState: { [key: string]: any }):
+		| string
+		| undefined => {
+		const apolloStateKeys = Object.keys(apolloState);
+		const key = apolloStateKeys.find((key) => key.includes("Listing"));
+		if (!key) return undefined;
+		return key;
+	};
+
+	const listingKey = getListingId(apolloState);
+
+	if (!listingKey) {
+		throw new Error("No listing key found in listing apolloState!");
+	}
+
+	const {
+		url,
+		title,
+		description,
+		price,
+		type,
+		status,
+		activationDate,
+		endDate,
+		metrics,
+		// attributes,
+		location,
+	} = apolloState[listingKey];
+
+	const listingObject = {
+		url,
+		title,
+		description,
+		listingPrice: {
+			amount: formatCentsToCurrency(price.amount),
+			currency: price.currency,
+		},
+		listingType: type,
+		listingStatus: status,
+		creationDate: activationDate,
+		endDate,
+		numberOfViews: metrics.views,
+		// condition: attributes.all.find(
+		// 	(attr: { [key: string]: unknown }) => attr.canonicalName === "condition",
+		// ).canonicalValues[0],
+		address: location.address,
+	};
+
+	return listingObject;
+};
+
+const searchHtml: string = await makeKijijiRequest(
+	`https://www.kijiji.ca/b-canada/${searchQuery}/k0l0?dc=true&view=list`,
+);
+
+const searchResults = parseSearch(searchHtml);
+
+// if (searchResults.length === 0) {
+//   throw new Error("Search didn't return an HTML!")
+// }
+// console.log(searchResults);
+
+const fetchAllWithRateLimit = async (links: string[]) => {
+	const results: string[] = [];
+	for (const link of links) {
+		try {
+			const data: string = await makeKijijiRequest(link);
+			// console.log(data);
+			results.push(data);
+		} catch (error) {
+			console.error(`Failed to fetch data from ${link}:`, error);
+		}
+		await delay(DELAY_MS);
+	}
+	return results;
+};
+
+const listingsLinks: string[] = searchResults.map((item) => {
+	return item.listingLink;
+});
+
+// console.log(listingsLinks);
+
+const fetchResults = await fetchAllWithRateLimit(listingsLinks);
+
+const itemsData = fetchResults.map((itemHtml) => parseListing(itemHtml));
+
+console.log(itemsData);