lens.model.ts

public async applyMapping(model: DTOModel): Promise<boolean> {
    // Todo: Jack Murphy - Here be Dragons!!!! This whole object should be processed by a single authority - IE ML tier.
    try {
      let lens: DTOLens = await this.lenses.createQueryBuilder('lens')
      .where(`lens.model = ${model.id}`)
      .leftJoinAndSelect("lens.model", "model")
      .leftJoinAndSelect("lens.modifiers", "modifiers")
      .getOne();
      
      // mappings is an array where the index is the old id and the value is the new id
      for (let originTopicId in model.mapping) {
        let newTopicId: string = model.mapping[originTopicId];
        let modDTO: DTOModifier = lens.modifiers.find((mod: DTOModifier) => mod.topicId === parseInt(originTopicId));
        let newTopic: number = parseInt(newTopicId);
        if (newTopic === -1) {
          await this.modifiers.remove(modDTO);
        } else {
          modDTO.topicId = newTopic;
          await this.modifiers.persist(modDTO);
        }
      }
      return true;
    } catch (e) {
      return false;
    }
  };