import {
  calculateSweetsWeightTotal,
  formatSweetWeightLabel,
} from '../sweets/pricing';

/** Shared order-line model used by cart, pre-order, and table orders. */

export type OrderPricingMode = 'standard' | 'weight';

export interface OrderLine {
  id: string;
  name: string;
  price: number;
  quantity: number;
  image?: string;
  pricingMode?: OrderPricingMode;
  pricePerKg?: number;
  pricePerHalfKg?: number;
}

export type NewOrderLine = Omit<OrderLine, 'quantity'>;

export function addOrderLine(lines: OrderLine[], item: NewOrderLine): OrderLine[] {
  const existing = lines.find((line) => line.id === item.id);
  if (existing) {
    return lines.map((line) =>
      line.id === item.id ? { ...line, quantity: line.quantity + 1 } : line
    );
  }
  return [...lines, { ...item, quantity: 1 }];
}

export function updateOrderLineQuantity(
  lines: OrderLine[],
  id: string,
  quantity: number
): OrderLine[] {
  if (quantity <= 0) {
    return lines.filter((line) => line.id !== id);
  }
  return lines.map((line) => (line.id === id ? { ...line, quantity } : line));
}

export function removeOrderLine(lines: OrderLine[], id: string): OrderLine[] {
  return lines.filter((line) => line.id !== id);
}

export function calculateLineTotal(line: OrderLine): number {
  if (line.pricingMode === 'weight') {
    return calculateSweetsWeightTotal(line.quantity);
  }
  return line.price * line.quantity;
}

export function calculateOrderTotal(lines: OrderLine[]): number {
  return lines.reduce((sum, line) => sum + calculateLineTotal(line), 0);
}

export function calculateOrderItemCount(lines: OrderLine[]): number {
  return lines.reduce((sum, line) => sum + line.quantity, 0);
}

export function formatOrderLinesForMessage(lines: OrderLine[]): string {
  return lines
    .map((line) => {
      const total = calculateLineTotal(line);
      if (line.pricingMode === 'weight') {
        const weight = formatSweetWeightLabel(line.quantity);
        return `${line.name} (${weight})  —  ${total} kr`;
      }
      return `${line.quantity} × ${line.name}  —  ${total} kr`;
    })
    .join('\n');
}

export function formatLineQuantityLabel(line: OrderLine): string {
  if (line.pricingMode === 'weight') {
    return formatSweetWeightLabel(line.quantity);
  }
  return String(line.quantity);
}