Initial commit: Telegram Management System

Full-stack web application for Telegram management
- Frontend: Vue 3 + Vben Admin
- Backend: NestJS
- Features: User management, group broadcast, statistics

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

marketing-agent/services/billing-service/src/models/Invoice.js

@@ -0,0 +1,257 @@
+import mongoose from 'mongoose';
+
+const invoiceSchema = new mongoose.Schema({
+  // Multi-tenant support
+  tenantId: {
+    type: mongoose.Schema.Types.ObjectId,
+    ref: 'Tenant',
+    required: true,
+    index: true
+  },
+  
+  // Invoice details
+  invoiceNumber: {
+    type: String,
+    required: true,
+    unique: true
+  },
+  subscriptionId: {
+    type: mongoose.Schema.Types.ObjectId,
+    ref: 'Subscription',
+    required: true
+  },
+  customerId: {
+    type: String,
+    required: true,
+    index: true
+  },
+  
+  // Billing period
+  periodStart: {
+    type: Date,
+    required: true
+  },
+  periodEnd: {
+    type: Date,
+    required: true
+  },
+  
+  // Status
+  status: {
+    type: String,
+    enum: ['draft', 'open', 'paid', 'void', 'uncollectible'],
+    default: 'draft',
+    index: true
+  },
+  
+  // Line items
+  lineItems: [{
+    description: String,
+    quantity: Number,
+    unitPrice: Number,
+    amount: Number,
+    currency: String,
+    period: {
+      start: Date,
+      end: Date
+    },
+    proration: Boolean,
+    type: {
+      type: String,
+      enum: ['subscription', 'usage', 'one_time', 'discount']
+    }
+  }],
+  
+  // Amounts
+  subtotal: {
+    type: Number,
+    required: true
+  },
+  tax: {
+    rate: Number,
+    amount: Number
+  },
+  discount: {
+    coupon: String,
+    amount: Number
+  },
+  total: {
+    type: Number,
+    required: true
+  },
+  currency: {
+    type: String,
+    default: 'USD'
+  },
+  
+  // Payment
+  amountPaid: {
+    type: Number,
+    default: 0
+  },
+  amountDue: {
+    type: Number,
+    required: true
+  },
+  attemptCount: {
+    type: Number,
+    default: 0
+  },
+  
+  // Dates
+  dueDate: Date,
+  paidAt: Date,
+  voidedAt: Date,
+  
+  // Payment details
+  paymentMethod: {
+    type: String,
+    last4: String,
+    brand: String
+  },
+  paymentIntent: String,
+  
+  // Customer details (snapshot at invoice time)
+  customer: {
+    name: String,
+    email: String,
+    phone: String,
+    address: {
+      line1: String,
+      line2: String,
+      city: String,
+      state: String,
+      postalCode: String,
+      country: String
+    }
+  },
+  
+  // PDF
+  pdfUrl: String,
+  
+  // Metadata
+  metadata: mongoose.Schema.Types.Mixed,
+  
+  // Stripe specific
+  stripeInvoiceId: String,
+  stripePaymentIntentId: String
+}, {
+  timestamps: true
+});
+
+// Indexes
+invoiceSchema.index({ tenantId: 1, status: 1 });
+invoiceSchema.index({ tenantId: 1, periodStart: -1 });
+invoiceSchema.index({ tenantId: 1, customerId: 1 });
+invoiceSchema.index({ tenantId: 1, invoiceNumber: 1 }, { unique: true });
+
+// Virtual for is overdue
+invoiceSchema.virtual('isOverdue').get(function() {
+  if (this.status !== 'open') return false;
+  if (!this.dueDate) return false;
+  return new Date() > this.dueDate;
+});
+
+// Virtual for days overdue
+invoiceSchema.virtual('daysOverdue').get(function() {
+  if (!this.isOverdue) return 0;
+  const now = new Date();
+  const due = new Date(this.dueDate);
+  return Math.floor((now - due) / (1000 * 60 * 60 * 24));
+});
+
+// Methods
+invoiceSchema.methods.addLineItem = function(item) {
+  this.lineItems.push(item);
+  this.calculateTotals();
+};
+
+invoiceSchema.methods.calculateTotals = function() {
+  // Calculate subtotal
+  this.subtotal = this.lineItems.reduce((sum, item) => {
+    if (item.type === 'discount') {
+      return sum - Math.abs(item.amount);
+    }
+    return sum + item.amount;
+  }, 0);
+  
+  // Apply tax
+  if (this.tax && this.tax.rate) {
+    this.tax.amount = this.subtotal * (this.tax.rate / 100);
+  }
+  
+  // Calculate total
+  this.total = this.subtotal + (this.tax?.amount || 0);
+  this.amountDue = this.total - this.amountPaid;
+};
+
+invoiceSchema.methods.markPaid = async function(paymentDetails) {
+  this.status = 'paid';
+  this.paidAt = new Date();
+  this.amountPaid = this.total;
+  this.amountDue = 0;
+  
+  if (paymentDetails) {
+    this.paymentMethod = paymentDetails.paymentMethod;
+    this.paymentIntent = paymentDetails.paymentIntent;
+  }
+  
+  await this.save();
+};
+
+invoiceSchema.methods.void = async function(reason) {
+  this.status = 'void';
+  this.voidedAt = new Date();
+  if (reason) {
+    this.metadata = this.metadata || {};
+    this.metadata.voidReason = reason;
+  }
+  await this.save();
+};
+
+invoiceSchema.methods.generatePDF = async function() {
+  // This would integrate with a PDF generation service
+  // For now, just return a placeholder
+  this.pdfUrl = `/invoices/${this.invoiceNumber}.pdf`;
+  await this.save();
+  return this.pdfUrl;
+};
+
+// Statics
+invoiceSchema.statics.generateInvoiceNumber = async function(tenantId) {
+  const date = new Date();
+  const year = date.getFullYear();
+  const month = String(date.getMonth() + 1).padStart(2, '0');
+  
+  // Find the last invoice for this tenant in the current month
+  const lastInvoice = await this.findOne({
+    tenantId,
+    invoiceNumber: new RegExp(`^INV-${year}${month}`)
+  }).sort({ invoiceNumber: -1 });
+  
+  let sequence = 1;
+  if (lastInvoice) {
+    const lastSequence = parseInt(lastInvoice.invoiceNumber.split('-').pop());
+    sequence = lastSequence + 1;
+  }
+  
+  return `INV-${year}${month}-${String(sequence).padStart(4, '0')}`;
+};
+
+invoiceSchema.statics.findUnpaid = function(tenantId) {
+  return this.find({
+    tenantId,
+    status: 'open',
+    amountDue: { $gt: 0 }
+  }).sort({ dueDate: 1 });
+};
+
+invoiceSchema.statics.findOverdue = function(tenantId) {
+  return this.find({
+    tenantId,
+    status: 'open',
+    dueDate: { $lt: new Date() }
+  }).sort({ dueDate: 1 });
+};
+
+export const Invoice = mongoose.model('Invoice', invoiceSchema);