feat: add XLSX export functionality for Stalker products and enhance UI for export link

src/server.ts

@@ -1,5 +1,6 @@
 import index from "./web/index.html";
 import path from "node:path";
+import * as XLSX from "xlsx";
 import { getDb, initDb } from "./database.ts";
 import {
   fetchKeepaDataBatch,
@@ -123,6 +124,16 @@ function csv(text: string, filename: string): Response {
   });
 }
 
+function xlsx(buffer: ArrayBuffer, filename: string): Response {
+  return new Response(buffer, {
+    status: 200,
+    headers: {
+      "content-type": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+      "content-disposition": `attachment; filename="${filename}"`,
+    },
+  });
+}
+
 function parseIntParam(value: string | null, fallback: number): number {
   if (!value) return fallback;
   const parsed = Number.parseInt(value, 10);
@@ -1025,6 +1036,123 @@ function getStalkerProducts(filters: URLSearchParams) {
   };
 }
 
+function getStalkerProductsForExport(filters: URLSearchParams): StalkerProductRecord[] {
+  const { where, params } = parseStalkerProductFilters(filters);
+  const orderBy = parseStalkerProductSort(filters.get("sort"));
+
+  return db
+    .query(
+      `SELECT * FROM (
+        SELECT
+          r.id AS runId,
+          r.started_at,
+          s.seller_id,
+          s.seller_name,
+          s.rating,
+          s.rating_count,
+          inv.asin,
+          inv.can_sell,
+          inv.sellability_status,
+          inv.sellability_reason,
+          inv.product_title,
+          inv.brand,
+          inv.category_tree,
+          inv.current_price,
+          inv.avg_price_90d,
+          inv.sales_rank,
+          inv.monthly_sold,
+          inv.seller_count,
+          inv.amazon_is_seller,
+          analysis.verdict,
+          analysis.confidence,
+          analysis.reasoning,
+          inv.last_seen_at
+        FROM stalker_seller_inventory inv
+        JOIN stalker_runs r ON r.id = inv.run_id
+        JOIN stalker_sellers s ON s.seller_id = inv.seller_id
+        LEFT JOIN product_analysis_results analysis ON analysis.asin = inv.asin
+        ${where}
+      ) stalker_products
+      ORDER BY ${orderBy}`,
+    )
+    .all(...params) as StalkerProductRecord[];
+}
+
+function parseCategoryTreeForExport(value: string | null): string {
+  if (!value) return "";
+  try {
+    const parsed = JSON.parse(value);
+    return Array.isArray(parsed)
+      ? parsed.filter((item) => typeof item === "string").join(" > ")
+      : "";
+  } catch {
+    return "";
+  }
+}
+
+function exportStalkerProductsXlsx(filters: URLSearchParams): Response {
+  const rows = getStalkerProductsForExport(filters);
+  const data = rows.map((row) => ({
+    ASIN: row.asin,
+    "Amazon URL": `https://amazon.com/dp/${row.asin}`,
+    Product: row.product_title ?? "",
+    Brand: row.brand ?? "",
+    Category: parseCategoryTreeForExport(row.category_tree),
+    "Monthly Sold": row.monthly_sold ?? null,
+    Sellers: row.seller_count ?? null,
+    "Amazon Seller": row.amazon_is_seller == null ? "" : row.amazon_is_seller === 1 ? "Yes" : "No",
+    "Sales Rank": row.sales_rank ?? null,
+    "Current Price": row.current_price ?? null,
+    "Avg 90d": row.avg_price_90d ?? null,
+    Verdict: row.verdict ?? "",
+    Confidence: row.confidence ?? null,
+    Reasoning: row.reasoning ?? "",
+    "Seller ID": row.seller_id,
+    Seller: row.seller_name ?? "",
+    "Seller Rating": row.rating ?? null,
+    "Seller Rating Count": row.rating_count ?? null,
+    "Sellability Status": row.sellability_status,
+    "Sellability Reason": row.sellability_reason ?? "",
+    "Run ID": row.runId,
+    "Last Seen": row.last_seen_at,
+  }));
+
+  const workbook = XLSX.utils.book_new();
+  const worksheet = XLSX.utils.json_to_sheet(data);
+  worksheet["!cols"] = [
+    { wch: 12 },
+    { wch: 32 },
+    { wch: 48 },
+    { wch: 20 },
+    { wch: 34 },
+    { wch: 14 },
+    { wch: 10 },
+    { wch: 14 },
+    { wch: 12 },
+    { wch: 12 },
+    { wch: 12 },
+    { wch: 10 },
+    { wch: 12 },
+    { wch: 60 },
+    { wch: 18 },
+    { wch: 24 },
+    { wch: 12 },
+    { wch: 20 },
+    { wch: 18 },
+    { wch: 40 },
+    { wch: 10 },
+    { wch: 24 },
+  ];
+  XLSX.utils.book_append_sheet(workbook, worksheet, "Sellable Products");
+
+  const buffer = XLSX.write(workbook, {
+    type: "array",
+    bookType: "xlsx",
+  }) as ArrayBuffer;
+
+  return xlsx(buffer, "stalker-sellable-products.xlsx");
+}
+
 function purgeStalkerData() {
   const counts = {
     inventory: (db.query("SELECT COUNT(*) AS count FROM stalker_seller_inventory").get() as { count: number }).count,
@@ -1694,6 +1822,10 @@ const server = Bun.serve({
       const url = new URL(req.url);
       return json(getStalkerProducts(url.searchParams));
     },
+    "/api/stalker/products/export.xlsx": (req) => {
+      const url = new URL(req.url);
+      return exportStalkerProductsXlsx(url.searchParams);
+    },
     "/api/stalker/purge": (req) => {
       if (req.method !== "DELETE" && req.method !== "POST") {
         return json({ error: "Method not allowed" }, 405);