feat: implement Forecast 2026 (Fc 26) tab with seasonality logic and actual sales comparison

api/fetch-forecast.ts

@@ -0,0 +1,49 @@
+
+import type { VercelRequest, VercelResponse } from '@vercel/node';
+import fs from 'fs';
+import path from 'path';
+
+export default async function handler(req: VercelRequest, res: VercelResponse) {
+    // CORS headers
+    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-forecast] Reading Forecast file from local storage...');
+        // Try multiple possible paths to be robust
+        const pathsToTry = [
+            path.join(process.cwd(), 'fc 26.xlsx'),
+            path.join(process.cwd(), 'public', 'fc 26.xlsx'),
+            path.join('/Users/christianvidalwolf/github/CrazeAnalytix', 'fc 26.xlsx') // Direct path as fallback for this environment
+        ];
+
+        let buffer = null;
+        let foundPath = '';
+
+        for (const p of pathsToTry) {
+            console.log(`[fetch-forecast] Checking path: ${p}`);
+            if (fs.existsSync(p)) {
+                buffer = fs.readFileSync(p);
+                foundPath = p;
+                break;
+            }
+        }
+
+        if (!buffer) {
+            throw new Error(`Forecast file 'fc 26.xlsx' not found in any of: ${pathsToTry.join(', ')}`);
+        }
+
+        console.log(`[fetch-forecast] Successfully read Forecast Excel from ${foundPath}, size: ${buffer.byteLength}`);
+
+        res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
+        res.status(200).send(buffer);
+    } catch (error: any) {
+        console.error('[fetch-forecast] Error:', error);
+        res.status(500).json({ error: error.message });
+    }
+}