export interface PosStockSaleLineInput {
  kind?: 'stock';
  variantId: string;
  quantity: number;
  discountCents?: number;
  // Legacy snapshot fields are accepted at the API boundary but ignored.
  productId?: string;
  sku?: string;
  ean?: string | null;
  name?: string;
  unitPriceCents?: number;
  taxCents?: number;
}

export interface PosFreeSaleLineInput {
  kind: 'free';
  name: string;
  unitPriceCents: number;
  quantity: number;
}

export type PosSaleLineInput = PosStockSaleLineInput | PosFreeSaleLineInput;

export interface PosSaleLineItem {
  kind: 'stock' | 'free';
  variantId: string | null;
  productId: string | null;
  sku: string;
  ean: string | null;
  name: string;
  unitPriceCents: number;
  discountCents: number;
  taxCents: number;
  quantity: number;
  vatRate: string | null;
}

export type PosPaymentKind = 'cash' | 'card' | 'other';

export interface PosPaymentInput {
  /** Configured payment method code. */
  methodCode?: string;
  /** Legacy field; used only to resolve cash/card defaults. */
  kind?: PosPaymentKind;
  amountCents: number;
  /** For cash payments: actual amount given by customer. */
  tenderedCents?: number;
  /** For card: last 4 digits if known. */
  last4?: string;
}

export interface PosSaleInput {
  idempotencyKey: string;
  cashSessionId: string;
  terminalId: string;
  userId: string;
  items: PosSaleLineInput[];
  payments: PosPaymentInput[];
  customerId?: string;
  /** Optional label for pending sales without customer */
  posLabel?: string;
  /** Club member ID — if provided and sale completes, cashback is accumulated to the member's ledger. */
  clubMemberId?: string;
}

export interface PosReceiptItem {
  name: string;
  sku: string;
  quantity: number;
  unitPriceCents: number;
  subtotalCents: number;
  discountCents: number;
  taxCents: number;
  totalCents: number;
  freeItem: boolean;
}

export interface PosReceiptPayment {
  methodCode: string;
  methodLabel: string;
  kind: PosPaymentKind;
  amountCents: number;
  tenderedCents: number | null;
  changeCents: number;
}

export interface PosReceipt {
  receiptNumber: string;
  orderId: string;
  issuedAt: Date;
  company: {
    name: string;
    address: string | null;
    taxId: string | null;
    email: string | null;
    phone: string | null;
  };
  /** URL del logo custom para el ticket. Si es null, usar /images/logo-main.png */
  logoUrl: string | null;
  terminal: { id: string; name: string };
  cashier: string;
  sessionId: string;
  customerEmail: string | null;
  items: PosReceiptItem[];
  subtotalCents: number;
  discountCents: number;
  taxCents: number;
  totalCents: number;
  payments: PosReceiptPayment[];
  changeCents: number;
  header: string | null;
  returnPolicy: string;
  footer: string | null;
  /** Present on return receipts. References the original ticket number. */
  originalReceiptNumber?: string;
  /** True for return/reversal receipts that should print negative totals. */
  isReturn?: boolean;
}

export interface PosSaleResult {
  orderId: string;
  idempotencyKey: string;
  receiptNumber: string;
  state: 'PENDING' | 'COMPLETED';
  totalCents: number;
  paidCents: number;
  outstandingCents: number;
  changeCents: number;
  items: PosSaleLineItem[];
  payments: PosPaymentResult[];
  receipt: PosReceipt;
  createdAt: Date;
  /** Cashback accumulated to the Club member's ledger (0 if no clubMemberId or sale is PENDING). */
  clubEarnedCents: number;
  /** Club member code when a clubMemberId was provided. */
  clubMemberCode?: string;
}

export interface PosPaymentResult extends PosReceiptPayment {
  id: string;
}

export interface PosReturnLineInput {
  orderItemId: string;
  returnedQuantity: number;
}

export interface PosReturnInput {
  orderId: string;
  idempotencyKey: string;
  cashSessionId: string;
  terminalId: string;
  userId: string;
  reason: string;
  lines: PosReturnLineInput[];
}

export interface PosReturnResult {
  orderId: string;
  returnId: string;
  idempotencyKey: string;
  state: 'PARTIALLY_REFUNDED' | 'REFUNDED';
  refundedCents: number;
  receipt: PosReceipt;
}