SaaS

# Multi-tenant SaaS 아키텍처 예시 (Django)
from django.db import models

class Tenant(models.Model):
    """테넌트 (고객사)"""
    name = models.CharField(max_length=100)
    subdomain = models.CharField(max_length=50, unique=True)
    plan = models.CharField(max_length=20, choices=[
        ('free', 'Free'),
        ('starter', 'Starter'),
        ('pro', 'Professional'),
        ('enterprise', 'Enterprise')
    ])
    created_at = models.DateTimeField(auto_now_add=True)

class TenantAwareModel(models.Model):
    """테넌트 종속 모델 베이스"""
    tenant = models.ForeignKey(Tenant, on_delete=models.CASCADE)

    class Meta:
        abstract = True

class Project(TenantAwareModel):
    """프로젝트 - 테넌트별 격리"""
    name = models.CharField(max_length=200)
    owner = models.ForeignKey('User', on_delete=models.CASCADE)

# 미들웨어 - 요청마다 테넌트 식별
class TenantMiddleware:
    def __init__(self, get_response):
        self.get_response = get_response

    def __call__(self, request):
        # 서브도메인에서 테넌트 추출
        # acme.myapp.com -> acme
        subdomain = request.get_host().split('.')[0]
        request.tenant = Tenant.objects.filter(
            subdomain=subdomain
        ).first()

        return self.get_response(request)

# 뷰에서 자동 필터링
class ProjectViewSet(viewsets.ModelViewSet):
    def get_queryset(self):
        # 현재 테넌트의 데이터만 조회
        return Project.objects.filter(
            tenant=self.request.tenant
        )

// Stripe 구독 관리 (Node.js)
import Stripe from 'stripe';

const stripe = new Stripe(process.env.STRIPE_SECRET_KEY);

// 고객 + 구독 생성
async function createSubscription(email, priceId, paymentMethodId) {
  // 1. Stripe 고객 생성
  const customer = await stripe.customers.create({
    email,
    payment_method: paymentMethodId,
    invoice_settings: {
      default_payment_method: paymentMethodId
    }
  });

  // 2. 구독 생성
  const subscription = await stripe.subscriptions.create({
    customer: customer.id,
    items: [{ price: priceId }],  // price_xxx (월간/연간)
    trial_period_days: 14,
    expand: ['latest_invoice.payment_intent']
  });

  return {
    subscriptionId: subscription.id,
    clientSecret: subscription.latest_invoice.payment_intent.client_secret,
    status: subscription.status
  };
}

// 플랜 업그레이드/다운그레이드
async function changePlan(subscriptionId, newPriceId) {
  const subscription = await stripe.subscriptions.retrieve(subscriptionId);

  return stripe.subscriptions.update(subscriptionId, {
    items: [{
      id: subscription.items.data[0].id,
      price: newPriceId
    }],
    proration_behavior: 'always_invoice'  // 차액 즉시 결제
  });
}

// Webhook 처리 (결제 이벤트)
async function handleWebhook(event) {
  switch (event.type) {
    case 'invoice.payment_succeeded':
      await activateSubscription(event.data.object.subscription);
      break;
    case 'invoice.payment_failed':
      await notifyPaymentFailure(event.data.object.customer);
      break;
    case 'customer.subscription.deleted':
      await deactivateAccount(event.data.object.customer);
      break;
  }
}

// SaaS API 통합 예시

// Slack API - 메시지 전송
async function sendSlackNotification(webhookUrl, message) {
  const response = await fetch(webhookUrl, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      text: message,
      attachments: [{
        color: '#36a64f',
        title: 'New Alert',
        fields: [
          { title: 'Status', value: 'Active', short: true },
          { title: 'Time', value: new Date().toISOString(), short: true }
        ]
      }]
    })
  });
  return response.ok;
}

// Notion API - 데이터베이스에 페이지 추가
async function createNotionPage(databaseId, properties) {
  const response = await fetch('https://api.notion.com/v1/pages', {
    method: 'POST',
    headers: {
      'Authorization': `Bearer ${process.env.NOTION_TOKEN}`,
      'Content-Type': 'application/json',
      'Notion-Version': '2022-06-28'
    },
    body: JSON.stringify({
      parent: { database_id: databaseId },
      properties: {
        Name: { title: [{ text: { content: properties.name } }] },
        Status: { select: { name: properties.status } },
        Due: { date: { start: properties.dueDate } }
      }
    })
  });
  return response.json();
}

// Salesforce API - 리드 생성
async function createSalesforceLead(accessToken, leadData) {
  const response = await fetch(
    `${process.env.SF_INSTANCE_URL}/services/data/v58.0/sobjects/Lead`,
    {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${accessToken}`,
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({
        FirstName: leadData.firstName,
        LastName: leadData.lastName,
        Company: leadData.company,
        Email: leadData.email
      })
    }
  );
  return response.json();
}