/**
 * Billing Domain - Contract
 * 
 * Defines the normalized billing types used throughout the application.
 * Provider-agnostic interface that all billing providers must map to.
 */

// Invoice Status
export const INVOICE_STATUS = {
  DRAFT: "Draft",
  PENDING: "Pending",
  PAID: "Paid",
  UNPAID: "Unpaid",
  OVERDUE: "Overdue",
  CANCELLED: "Cancelled",
  REFUNDED: "Refunded",
  COLLECTIONS: "Collections",
} as const;

export type InvoiceStatus = (typeof INVOICE_STATUS)[keyof typeof INVOICE_STATUS];

// Invoice Item
export interface InvoiceItem {
  id: number;
  description: string;
  amount: number;
  quantity?: number;
  type: string;
  serviceId?: number;
}

// Invoice
export interface Invoice {
  id: number;
  number: string;
  status: InvoiceStatus;
  currency: string;
  currencySymbol?: string;
  total: number;
  subtotal: number;
  tax: number;
  issuedAt?: string;
  dueDate?: string;
  paidDate?: string;
  pdfUrl?: string;
  paymentUrl?: string;
  description?: string;
  items?: InvoiceItem[];
  daysOverdue?: number;
}

// Invoice Pagination
export interface InvoicePagination {
  page: number;
  totalPages: number;
  totalItems: number;
  nextCursor?: string;
}

// Invoice List
export interface InvoiceList {
  invoices: Invoice[];
  pagination: InvoicePagination;
}

// SSO Link for invoice payment
export interface InvoiceSsoLink {
  url: string;
  expiresAt: string;
}

// Payment request for invoice
export interface PaymentInvoiceRequest {
  invoiceId: number;
  paymentMethodId?: number;
  gatewayName?: string;
  amount?: number;
}

// Billing Summary (calculated from invoices)
export interface BillingSummary {
  totalOutstanding: number;
  totalOverdue: number;
  totalPaid: number;
  currency: string;
  currencySymbol?: string;
  invoiceCount: {
    total: number;
    unpaid: number;
    overdue: number;
    paid: number;
  };
}