import { Column, Entity, ManyToOne, PrimaryGeneratedColumn } from 'typeorm';
import { TransformationType } from './transformation-type';
import { Work } from './work';

/**
 * This entity describes how one work is transformed to another.
 */
@Entity()
export class Transformation implements IIdentifiableEntity, IOrderableEntity {
  @PrimaryGeneratedColumn()
  public id: number;

  /**
   * the work based on the original
   */
  @ManyToOne(
    () => Work,
    (work: Work) => work.transformationOf,
    {
      nullable: false,
      onDelete: 'CASCADE',
      onUpdate: 'CASCADE',
    }
  )
  public byWork: Promise<Work>;

  /**
   * the transformation type
   */
  @ManyToOne(
    () => TransformationType,
    (transformationType: TransformationType) => transformationType.transformations,
    {
      nullable: false,
      onDelete: 'RESTRICT',
      onUpdate: 'CASCADE',
    }
  )
  public type: Promise<TransformationType>;

  /**
   * the original work
   */
  @ManyToOne(
    () => Work,
    (work: Work) => work.transformedBy,
    {
      nullable: false,
      onDelete: 'CASCADE',
      onUpdate: 'CASCADE',
    }
  )
  public ofWork: Promise<Work>;

  @Column({
    nullable: false,
    default: 0,
  })
  public order: number;
}