Integración

┌─────────────────────────────────────────────────────────────┐
│                       Tu Frontend                            │
│                    (React, Vue, etc.)                        │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                       Tu Backend                             │
│              (Node.js, Python, etc.)                         │
│                                                              │
│  ┌─────────────────┐  ┌─────────────────┐                   │
│  │  pan Service    │  │  Tu Base de     │                   │
│  │  (SDK)          │  │  Datos          │                   │
│  └─────────────────┘  └─────────────────┘                   │
└─────────────────────────────────────────────────────────────┘
                              │
                              ▼
┌─────────────────────────────────────────────────────────────┐
│                        pan API                               │
└─────────────────────────────────────────────────────────────┘

// services/pan.service.ts
import { Pan, Wallet, Balances, Intent } from '@pan/sdk';
import { prisma } from './db';

class PanService {
  private pan: Pan;

  constructor() {
    this.pan = new Pan({
      apiKey: process.env.PAN_API_KEY!
    });
  }

  async createWalletForUser(userId: string, email?: string): Promise<Wallet> {
    // Verificar si ya existe
    const user = await prisma.user.findUnique({
      where: { id: userId }
    });

    if (user?.panWalletId) {
      return await this.pan.wallet.get(userId);
    }

    // Crear wallet
    const wallet = await this.pan.wallet.create({
      userId,
      email,
      metadata: { createdAt: new Date().toISOString() }
    });

    // Guardar referencia
    await prisma.user.update({
      where: { id: userId },
      data: {
        panWalletId: wallet.id,
        panWalletAddress: wallet.address
      }
    });

    return wallet;
  }

  async getBalances(userId: string): Promise<Balances> {
    const user = await prisma.user.findUnique({
      where: { id: userId }
    });

    if (!user?.panWalletId) {
      throw new Error('Usuario no tiene wallet');
    }

    return await this.pan.wallet.getBalances(user.panWalletId);
  }

  async lend(userId: string, amount: number): Promise<Intent> {
    const user = await prisma.user.findUnique({
      where: { id: userId }
    });

    if (!user?.panWalletId) {
      throw new Error('Usuario no tiene wallet');
    }

    const intent = await this.pan.lend({
      walletId: user.panWalletId,
      amount,
      asset: 'USDC'
    });

    // Guardar intent en tu DB
    await prisma.transaction.create({
      data: {
        userId,
        panIntentId: intent.id,
        type: 'LEND',
        amount,
        status: intent.status
      }
    });

    return intent;
  }
}

export const panService = new PanService();

// app/api/wallet/route.ts
import { NextResponse } from 'next/server';
import { panService } from '@/services/pan.service';
import { getServerSession } from 'next-auth';

export async function POST(request: Request) {
  const session = await getServerSession();
  if (!session?.user) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  try {
    const wallet = await panService.createWalletForUser(
      session.user.id,
      session.user.email
    );

    return NextResponse.json(wallet);
  } catch (error) {
    return NextResponse.json(
      { error: error.message },
      { status: 500 }
    );
  }
}

export async function GET(request: Request) {
  const session = await getServerSession();
  if (!session?.user) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  try {
    const balances = await panService.getBalances(session.user.id);
    return NextResponse.json(balances);
  } catch (error) {
    return NextResponse.json(
      { error: error.message },
      { status: 500 }
    );
  }
}

// app/api/webhooks/pan/route.ts
export async function POST(request: Request) {
  const body = await request.json();

  // Verificar firma
  const signature = request.headers.get('x-pan-signature');
  if (!verifySignature(body, signature)) {
    return new Response('Invalid signature', { status: 401 });
  }

  switch (body.event) {
    case 'intent.completed':
      await handleIntentCompleted(body.data);
      break;

    case 'intent.failed':
      await handleIntentFailed(body.data);
      break;
  }

  return new Response('OK');
}

async function handleIntentCompleted(data: any) {
  await prisma.transaction.update({
    where: { panIntentId: data.intentId },
    data: {
      status: 'COMPLETED',
      completedAt: new Date()
    }
  });

  // Notificar usuario
  await sendNotification(data.userId, 'Tu depósito fue exitoso!');
}

// hooks/usePanWallet.ts
import { useState, useEffect, useCallback } from 'react';

export function usePanWallet() {
  const [wallet, setWallet] = useState(null);
  const [balances, setBalances] = useState(null);
  const [loading, setLoading] = useState(true);

  const fetchWallet = useCallback(async () => {
    const response = await fetch('/api/wallet');
    if (response.ok) {
      const data = await response.json();
      setWallet(data.wallet);
      setBalances(data.balances);
    }
    setLoading(false);
  }, []);

  useEffect(() => {
    fetchWallet();
  }, [fetchWallet]);

  const createWallet = async () => {
    const response = await fetch('/api/wallet', { method: 'POST' });
    if (response.ok) {
      await fetchWallet();
    }
  };

  const refreshBalances = async () => {
    const response = await fetch('/api/wallet');
    if (response.ok) {
      const data = await response.json();
      setBalances(data.balances);
    }
  };

  return {
    wallet,
    balances,
    loading,
    createWallet,
    refreshBalances,
    hasWallet: !!wallet
  };
}

// prisma/schema.prisma
model User {
  id               String        @id @default(cuid())
  email            String        @unique
  panWalletId      String?
  panWalletAddress String?
  transactions     Transaction[]
  createdAt        DateTime      @default(now())
}

model Transaction {
  id           String   @id @default(cuid())
  userId       String
  user         User     @relation(fields: [userId], references: [id])
  panIntentId  String   @unique
  type         String   // LEND, WITHDRAW, BRIDGE
  amount       Float
  asset        String   @default("USDC")
  status       String   // PENDING, EXECUTING, COMPLETED, FAILED
  txHashes     String[] // Transaction hashes
  gasCostUsd   Float?
  completedAt  DateTime?
  createdAt    DateTime @default(now())
}

// Flujo completo de lending
async function lendingFlow(userId: string, amount: number) {
  // 1. Verificar wallet existe
  let wallet = await panService.getWallet(userId);

  if (!wallet) {
    wallet = await panService.createWallet(userId);
  }

  // 2. Verificar fondos
  const balances = await panService.getBalances(userId);
  const usdcTotal = calculateTotal(balances, 'USDC');

  if (usdcTotal < amount) {
    throw new Error(`Fondos insuficientes: ${usdcTotal} < ${amount}`);
  }

  // 3. Crear intent
  const intent = await panService.lend(userId, amount);

  // 4. Monitorear (o usar webhooks)
  return await panService.waitForIntent(intent.id);
}