import { IsOptional, IsInt, Min, Max, IsString, IsIn } from 'class-validator';
import { Transform } from 'class-transformer';
import { ApiPropertyOptional } from '@nestjs/swagger';

export class PaginationDto {
  @ApiPropertyOptional({ default: 1, minimum: 1, description: 'Page number' })
  @IsOptional()
  @Transform(({ value }) => parseInt(value, 10))
  @IsInt()
  @Min(1)
  page?: number = 1;

  @ApiPropertyOptional({
    default: 10,
    minimum: 1,
    maximum: 100,
    description: 'Items per page',
  })
  @IsOptional()
  @Transform(({ value }) => parseInt(value, 10))
  @IsInt()
  @Min(1)
  @Max(100)
  limit?: number = 10;

  @ApiPropertyOptional({ description: 'Field to sort by' })
  @IsOptional()
  @IsString()
  sortBy?: string = 'createdAt';

  @ApiPropertyOptional({
    enum: ['asc', 'desc'],
    default: 'desc',
    description: 'Sort order',
  })
  @IsOptional()
  @IsIn(['asc', 'desc'])
  sortOrder?: 'asc' | 'desc' = 'desc';

  @ApiPropertyOptional({ description: 'Search query' })
  @IsOptional()
  @IsString()
  search?: string;

  /**
   * Get skip value for Prisma
   */
  get skip(): number {
    return ((this.page || 1) - 1) * (this.limit || 10);
  }

  /**
   * Get take value for Prisma
   */
  get take(): number {
    return this.limit || 10;
  }

  /**
   * Get orderBy object for Prisma
   */
  get orderBy(): Record<string, 'asc' | 'desc'> {
    return { [this.sortBy || 'createdAt']: this.sortOrder || 'desc' };
  }
}