import { BaseEntity } from '../infrastructure/Entity/BaseEntity';
import { IScript } from './IScript';
import { ICategory } from './ICategory';

export class Category extends BaseEntity<number> implements ICategory {
  private allSubScripts: ReadonlyArray<IScript> = undefined;

  constructor(
    id: number,
    public readonly name: string,
    public readonly documentationUrls: ReadonlyArray<string>,
    public readonly subCategories?: ReadonlyArray<ICategory>,
    public readonly scripts?: ReadonlyArray<IScript>,
  ) {
    super(id);
    validateCategory(this);
  }

  public includes(script: IScript): boolean {
    return this.getAllScriptsRecursively().some((childScript) => childScript.id === script.id);
  }

  public getAllScriptsRecursively(): readonly IScript[] {
    if (!this.allSubScripts) {
      this.allSubScripts = parseScriptsRecursively(this);
    }
    return this.allSubScripts;
  }
}

function parseScriptsRecursively(category: ICategory): ReadonlyArray<IScript> {
  return [
    ...category.scripts,
    ...category.subCategories.flatMap((c) => c.getAllScriptsRecursively()),
  ];
}

function validateCategory(category: ICategory) {
  if (!category.name) {
    throw new Error('missing name');
  }
  if (
    (!category.subCategories || category.subCategories.length === 0)
      && (!category.scripts || category.scripts.length === 0)
  ) {
    throw new Error('A category must have at least one sub-category or script');
  }
}