refactor: consolidate 3 MKT fetch routes into fetch-mkt-data to stay within Vercel 12-function limit

Replace fetch-deals, fetch-promos, fetch-chargebacks with a single
/api/fetch-mkt-data?file=deals|promos|chargebacks endpoint.
Update MktDataView fetch calls accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

api/fetch-chargebacks.ts

@@ -1,37 +0,0 @@
-import type { VercelRequest, VercelResponse } from '@vercel/node';
-
-const CHARGEBACKS_DROPBOX_URL = "https://www.dropbox.com/scl/fi/m2qr2cxhtgkc48acjrrgx/Amazon-Operational-Chargebacks-2025.xlsx?rlkey=vlrz4qfydsjtikgh0ylivocjq&st=zdhmjvaz&dl=1";
-
-export default async function handler(req: VercelRequest, res: VercelResponse) {
-    res.setHeader('Access-Control-Allow-Origin', '*');
-    res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
-    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
-
-    if (req.method === 'OPTIONS') {
-        return res.status(200).end();
-    }
-
-    try {
-        console.log('[fetch-chargebacks] Fetching Chargebacks from Dropbox...');
-        const response = await fetch(CHARGEBACKS_DROPBOX_URL, {
-            cache: 'no-store',
-            headers: {
-                'Pragma': 'no-cache',
-                'Cache-Control': 'no-cache'
-            }
-        });
-
-        if (!response.ok) {
-            throw new Error(`Dropbox responded with ${response.status}`);
-        }
-
-        const buffer = await response.arrayBuffer();
-        console.log('[fetch-chargebacks] Successfully fetched Chargebacks Excel, size:', buffer.byteLength);
-
-        res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
-        res.status(200).send(Buffer.from(buffer));
-    } catch (error: any) {
-        console.error('[fetch-chargebacks] Error:', error);
-        res.status(500).json({ error: error.message });
-    }
-}

api/fetch-deals.ts

@@ -1,37 +0,0 @@
-import type { VercelRequest, VercelResponse } from '@vercel/node';
-
-const DEALS_DROPBOX_URL = "https://www.dropbox.com/scl/fi/3mm5m4e04myhqt59piefs/Deals-Amazon-2025.xlsx?rlkey=6llr0xhs6di0c3d8o96ashzmv&st=ggu0z7hu&dl=1";
-
-export default async function handler(req: VercelRequest, res: VercelResponse) {
-    res.setHeader('Access-Control-Allow-Origin', '*');
-    res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
-    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
-
-    if (req.method === 'OPTIONS') {
-        return res.status(200).end();
-    }
-
-    try {
-        console.log('[fetch-deals] Fetching Deals from Dropbox...');
-        const response = await fetch(DEALS_DROPBOX_URL, {
-            cache: 'no-store',
-            headers: {
-                'Pragma': 'no-cache',
-                'Cache-Control': 'no-cache'
-            }
-        });
-
-        if (!response.ok) {
-            throw new Error(`Dropbox responded with ${response.status}`);
-        }
-
-        const buffer = await response.arrayBuffer();
-        console.log('[fetch-deals] Successfully fetched Deals Excel, size:', buffer.byteLength);
-
-        res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
-        res.status(200).send(Buffer.from(buffer));
-    } catch (error: any) {
-        console.error('[fetch-deals] Error:', error);
-        res.status(500).json({ error: error.message });
-    }
-}

api/fetch-mkt-data.ts

@@ -0,0 +1,45 @@
+import type { VercelRequest, VercelResponse } from '@vercel/node';
+
+const FILE_URLS: Record<string, string> = {
+  deals: "https://www.dropbox.com/scl/fi/3mm5m4e04myhqt59piefs/Deals-Amazon-2025.xlsx?rlkey=6llr0xhs6di0c3d8o96ashzmv&st=ggu0z7hu&dl=1",
+  promos: "https://www.dropbox.com/scl/fi/ufhej9do9w839oyyfrpk3/Promos_Amazon_2025_all-countries.xlsx?rlkey=4foano9dt5h3sl58l35vqg89d&st=wu0t56wh&dl=1",
+  chargebacks: "https://www.dropbox.com/scl/fi/m2qr2cxhtgkc48acjrrgx/Amazon-Operational-Chargebacks-2025.xlsx?rlkey=vlrz4qfydsjtikgh0ylivocjq&st=zdhmjvaz&dl=1",
+};
+
+export default async function handler(req: VercelRequest, res: VercelResponse) {
+  res.setHeader('Access-Control-Allow-Origin', '*');
+  res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
+  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
+
+  if (req.method === 'OPTIONS') {
+    return res.status(200).end();
+  }
+
+  const file = req.query.file as string;
+  const url = FILE_URLS[file];
+
+  if (!url) {
+    return res.status(400).json({ error: `Unknown file: "${file}". Valid options: deals, promos, chargebacks` });
+  }
+
+  try {
+    console.log(`[fetch-mkt-data] Fetching ${file} from Dropbox...`);
+    const response = await fetch(url, {
+      cache: 'no-store',
+      headers: { 'Pragma': 'no-cache', 'Cache-Control': 'no-cache' }
+    });
+
+    if (!response.ok) {
+      throw new Error(`Dropbox responded with ${response.status}`);
+    }
+
+    const buffer = await response.arrayBuffer();
+    console.log(`[fetch-mkt-data] Successfully fetched ${file}, size:`, buffer.byteLength);
+
+    res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
+    res.status(200).send(Buffer.from(buffer));
+  } catch (error: any) {
+    console.error(`[fetch-mkt-data] Error fetching ${file}:`, error);
+    res.status(500).json({ error: error.message });
+  }
+}

api/fetch-promos.ts

@@ -1,37 +0,0 @@
-import type { VercelRequest, VercelResponse } from '@vercel/node';
-
-const PROMOS_DROPBOX_URL = "https://www.dropbox.com/scl/fi/ufhej9do9w839oyyfrpk3/Promos_Amazon_2025_all-countries.xlsx?rlkey=4foano9dt5h3sl58l35vqg89d&st=wu0t56wh&dl=1";
-
-export default async function handler(req: VercelRequest, res: VercelResponse) {
-    res.setHeader('Access-Control-Allow-Origin', '*');
-    res.setHeader('Access-Control-Allow-Methods', 'GET, OPTIONS');
-    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
-
-    if (req.method === 'OPTIONS') {
-        return res.status(200).end();
-    }
-
-    try {
-        console.log('[fetch-promos] Fetching Promos from Dropbox...');
-        const response = await fetch(PROMOS_DROPBOX_URL, {
-            cache: 'no-store',
-            headers: {
-                'Pragma': 'no-cache',
-                'Cache-Control': 'no-cache'
-            }
-        });
-
-        if (!response.ok) {
-            throw new Error(`Dropbox responded with ${response.status}`);
-        }
-
-        const buffer = await response.arrayBuffer();
-        console.log('[fetch-promos] Successfully fetched Promos Excel, size:', buffer.byteLength);
-
-        res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
-        res.status(200).send(Buffer.from(buffer));
-    } catch (error: any) {
-        console.error('[fetch-promos] Error:', error);
-        res.status(500).json({ error: error.message });
-    }
-}

components/mkt/MktDataView.tsx

@@ -109,9 +109,9 @@ export default function MktDataView({ rawData, adsData }: MktDataViewProps) {
       setMktLoading(true);
       try {
         const [dealsRes, promosRes, chargesRes] = await Promise.all([
-          fetch('/api/fetch-deals'),
+          fetch('/api/fetch-mkt-data?file=deals'),
-          fetch('/api/fetch-promos'),
+          fetch('/api/fetch-mkt-data?file=promos'),
-          fetch('/api/fetch-chargebacks'),
+          fetch('/api/fetch-mkt-data?file=chargebacks'),
         ]);
 
         if (cancelled) return;
@@ -120,21 +120,21 @@ export default function MktDataView({ rawData, adsData }: MktDataViewProps) {
           const buf = await dealsRes.arrayBuffer();
           if (!cancelled) setDealsMap(parseDealsExcel(buf));
         } else {
-          console.warn('[MktDataView] fetch-deals failed:', dealsRes.status);
+          console.warn('[MktDataView] fetch-mkt-data?file=deals failed:', dealsRes.status);
         }
 
         if (promosRes.ok) {
           const buf = await promosRes.arrayBuffer();
           if (!cancelled) setPromosMap(parsePromosExcel(buf));
         } else {
-          console.warn('[MktDataView] fetch-promos failed:', promosRes.status);
+          console.warn('[MktDataView] fetch-mkt-data?file=promos failed:', promosRes.status);
         }
 
         if (chargesRes.ok) {
           const buf = await chargesRes.arrayBuffer();
           if (!cancelled) setChargebacksMap(parseChargebacksExcel(buf));
         } else {
-          console.warn('[MktDataView] fetch-chargebacks failed:', chargesRes.status);
+          console.warn('[MktDataView] fetch-mkt-data?file=chargebacks failed:', chargesRes.status);
         }
       } catch (e) {
         console.error('[MktDataView] Error fetching marketing data:', e);