import { Type } from 'class-transformer';
import {
  ArrayMaxSize,
  ArrayMinSize,
  IsArray,
  IsInt,
  IsString,
  Min,
  ValidateNested,
} from 'class-validator';

export class ExchangeItemDto {
  @IsString()
  itemKey!: string;

  @IsInt()
  @Min(1)
  quantity!: number;
}

export class ExchangeRequestDto {
  /**
   * Item keys and quantities only.
   *
   * Prices and rewards are never accepted from the client -- the server reads
   * them from the exchange rules (slice §8, NPC spec §37.9). The upper bound
   * keeps one request from turning into an unbounded row-by-row transaction.
   */
  @IsArray()
  @ArrayMinSize(1)
  @ArrayMaxSize(50)
  @ValidateNested({ each: true })
  @Type(() => ExchangeItemDto)
  items!: ExchangeItemDto[];
}