import { Money } from '../value-objects/Money.js';
import { TipoTributo } from '../value-objects/FiscalEnums.js';
import { ValidacionFiscalException } from '../exceptions/ValidacionFiscalException.js';

export interface ItemFacturaProps {
  id?: string;
  lineNumber: number;
  sku: string;
  description: string;
  quantity: number;
  unitCode?: string;
  unitPrice: number;
  taxPercentage?: number;
  taxTypeCode?: TipoTributo;
  discountAmount?: number;
}

export class ItemFactura {
  public readonly id?: string;
  public readonly lineNumber: number;
  public readonly sku: string;
  public readonly description: string;
  public readonly quantity: number;
  public readonly unitCode: string;
  public readonly unitPrice: Money;
  public readonly totalCost: Money;
  public readonly taxPercentage: number;
  public readonly taxAmount: Money;
  public readonly taxTypeCode: TipoTributo;
  public readonly discountAmount: Money;

  constructor(props: ItemFacturaProps) {
    if (props.quantity <= 0) {
      throw new ValidacionFiscalException(`La cantidad del item ${props.sku} debe ser mayor a 0.`);
    }
    if (props.unitPrice < 0) {
      throw new ValidacionFiscalException(`El precio unitario del item ${props.sku} no puede ser negativo.`);
    }

    this.id = props.id;
    this.lineNumber = props.lineNumber;
    this.sku = props.sku.trim();
    this.description = props.description.trim();
    this.quantity = props.quantity;
    this.unitCode = props.unitCode || 'EA'; // EA: Cada / Unidad
    this.unitPrice = Money.from(props.unitPrice);
    
    // Subtotal línea = cantidad * precio unitario
    this.totalCost = this.unitPrice.multiply(this.quantity);
    
    this.discountAmount = Money.from(props.discountAmount || 0);
    this.taxPercentage = props.taxPercentage ?? 19.0;
    this.taxTypeCode = props.taxTypeCode || TipoTributo.IVA;

    // Base imponible = totalCost - discountAmount
    const baseImponible = this.totalCost.subtract(this.discountAmount);
    this.taxAmount = baseImponible.calculateTax(this.taxPercentage);
  }

  public get subtotalNeto(): Money {
    return this.totalCost.subtract(this.discountAmount);
  }

  public get totalConImpuesto(): Money {
    return this.subtotalNeto.add(this.taxAmount);
  }
}