Refactor: Fully migrated to direct PostgreSQL, implemented Public API v1, fixed Vercel deployment conflicts, and updated documentation

app/api/v1/checkout/route.ts

@@ -0,0 +1,129 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { db } from '@/lib/db';
+import { validateApiKey } from '@/lib/api-auth';
+import { CryptoEngine } from '@/lib/crypto-engine';
+import { PaymentProviderFactory } from '@/lib/payment-providers';
+
+/**
+ * Public API for Merchants to create a payment session
+ * POST /api/v1/checkout
+ * Header: x-api-key: YOUR_API_KEY
+ */
+export async function POST(req: NextRequest) {
+  try {
+    const apiKey = req.headers.get('x-api-key');
+    const merchant = await validateApiKey(apiKey);
+
+    if (!merchant) {
+      return NextResponse.json(
+        { error: 'Unauthorized. Invalid API Key.' },
+        { status: 401 }
+      );
+    }
+
+    const { 
+      amount, 
+      currency = 'TRY', 
+      order_id, 
+      callback_url, 
+      customer_name, 
+      customer_phone,
+      success_url,
+      cancel_url 
+    } = await req.json();
+
+    if (!amount) {
+      return NextResponse.json(
+        { error: 'Amount is required.' },
+        { status: 400 }
+      );
+    }
+
+    // 1. Determine provider
+    const provider = merchant.payment_provider || 'stripe';
+    const useMock = process.env.NEXT_PUBLIC_USE_MOCK_PAYMENTS === 'true';
+
+    let clientSecret = '';
+    let providerTxId = '';
+    let nextAction = 'none';
+    let redirectUrl = '';
+
+    // Generate Temporary Wallets for Crypto fallback
+    const evmWallet = await CryptoEngine.createTemporaryWallet('POLYGON');
+    const solWallet = await CryptoEngine.createTemporaryWallet('SOLANA');
+
+    const cryptoWallets = {
+        EVM: { address: evmWallet.address, privateKey: evmWallet.privateKey },
+        SOLANA: { address: solWallet.address, privateKey: solWallet.privateKey }
+    };
+
+    if (useMock) {
+        clientSecret = 'mock_secret_' + Math.random().toString(36).substring(7);
+        providerTxId = clientSecret;
+    } else {
+        // Use Factory to create intent based on provider (Stripe, etc.)
+        const intent = await PaymentProviderFactory.createIntent(provider, {
+            amount,
+            currency,
+            merchantId: merchant.id,
+            refId: order_id,
+            customerName: customer_name,
+            customerPhone: customer_phone,
+            callbackUrl: callback_url || success_url,
+            providerConfig: merchant.provider_config
+        });
+
+        clientSecret = intent.clientSecret;
+        providerTxId = intent.providerTxId;
+        nextAction = intent.nextAction || 'none';
+        redirectUrl = intent.redirectUrl || '';
+    }
+
+    // 2. Insert Transaction into DB
+    const txResult = await db.query(`
+        INSERT INTO transactions (
+            amount, currency, status, stripe_pi_id, source_ref_id, 
+            customer_name, customer_phone, callback_url, merchant_id, 
+            provider, metadata
+        ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
+        RETURNING id
+    `, [
+        amount, currency, 'pending', providerTxId, order_id,
+        customer_name, customer_phone, callback_url || success_url, merchant.id,
+        provider, JSON.stringify({
+            nextAction,
+            redirectUrl,
+            wallets: cryptoWallets,
+            success_url,
+            cancel_url
+        })
+    ]);
+
+    const txId = txResult.rows[0].id;
+    const baseUrl = process.env.NEXT_PUBLIC_BASE_URL || 'http://localhost:3000';
+
+    // 3. Return response with checkout URL
+    return NextResponse.json({
+      success: true,
+      data: {
+        id: txId,
+        amount,
+        currency,
+        order_id,
+        checkout_url: `${baseUrl}/checkout?session_id=${txId}`,
+        status: 'pending',
+        wallets: {
+          EVM: evmWallet.address,
+          SOLANA: solWallet.address
+        }
+      }
+    });
+
+  } catch (error: any) {
+    console.error('Public API Error:', error);
+    return NextResponse.json(
+      { error: 'Internal Server Error' },
+      { status: 500 }
+    );
+  }
+}