feat: implement platform treasury model with merchant balance tracking and API docs

app/api/crypto-sweep/route.ts

@@ -95,27 +95,37 @@ export async function POST(request: Request) {
             });
         }
 
-        // 6. Proceed to Sweep
+        // 6. Proceed to Sweep (100% to platform treasury)
         const sweepResult = await cryptoEngine.sweepFunds(
             tempWalletConfig.privateKey,
-            merchantAddress,
             platformAddress,
-            selectedToken,
-            feePercent
+            selectedToken
         );
 
         if (!sweepResult.success) {
             throw new Error("Süpürme işlemi başarısız oldu.");
         }
 
-        // 6. Update transaction status
+        // 6.1 Calculate Merchant's credit (Amount - Platform Fee)
+        // Note: transaction.amount is the gross amount paid by customer
+        const grossAmount = parseFloat(transaction.amount);
+        const feeAmount = (grossAmount * feePercent) / 100;
+        const merchantNetCredit = grossAmount - feeAmount;
+
+        // 6.2 Update Merchant's virtual balance in DB
+        await db.query(`
+            UPDATE merchants 
+            SET available_balance = available_balance + $1 
+            WHERE id = $2
+        `, [merchantNetCredit, transaction.merchant_id]);
+
+        // 6.3 Update transaction status
         await db.query(`UPDATE transactions SET status = 'succeeded' WHERE id = $1`, [transaction.id]);
 
         // 7. Automated Webhook Notification
         if (transaction.callback_url) {
             console.log(`[Webhook] Notifying merchant at ${transaction.callback_url}`);
             try {
-                // In production, sign this payload and use a more robust delivery system
                 fetch(transaction.callback_url, {
                     method: 'POST',
                     headers: { 'Content-Type': 'application/json' },
@@ -123,7 +133,7 @@ export async function POST(request: Request) {
                         status: 'success',
                         txId: transaction.stripe_pi_id,
                         orderRef: transaction.source_ref_id,
-                        hashes: sweepResult
+                        hashes: { txHash: sweepResult.txHash }
                     })
                 }).catch(e => console.error("Webhook fetch failed:", e.message));
             } catch (webhookError: any) {
@@ -133,11 +143,11 @@ export async function POST(request: Request) {
 
         return NextResponse.json({
             success: true,
-            message: `Ödeme ${selectedNetwork} ağında ${selectedToken} ile başarıyla doğrulandı ve süpürüldü.`,
+            message: `Ödeme ${selectedNetwork} ağında ${selectedToken} ile başarıyla doğrulandı, hazineye aktarıldı ve merchant bakiyesi güncellendi.`,
             hashes: {
-                platform: sweepResult.platformTx,
-                merchant: sweepResult.merchantTx
-            }
+                txHash: sweepResult.txHash
+            },
+            merchantCredit: merchantNetCredit
         });
 
     } catch (error: any) {