import { Injectable } from "@nestjs/common";
import type { Prisma } from "@prisma/client";
import { cvMapper } from "@/modules/cv-template/cv.mapper";
import { VacancyMapper } from "@/modules/vacancies/vacancy.mapper";
import {
  Application,
  type ApplicationStatusRelation,
} from "./application.entity";

type PrismaApplicationWithRelations = Prisma.ApplicationGetPayload<{
  include: {
    user: true;
    status: true;
    vacancy: {
      include: {
        company: true;
        role: true;
        level: true;
        jobType: true;
        skills: true;
      };
    };
    cv: {
      include: {
        template: true;
      };
    };
  };
}>;

@Injectable()
export class ApplicationMapper {
  constructor(private readonly vacancyMapper: VacancyMapper) {}

  toDomain(
    prismaApplication: PrismaApplicationWithRelations | null,
  ): Application | null {
    if (!prismaApplication) {
      return null;
    }

    const status: ApplicationStatusRelation = {
      id: prismaApplication.status.id,
      name: prismaApplication.status.name,
      description: prismaApplication.status.description,
      createdAt: prismaApplication.status.createdAt,
      updatedAt: prismaApplication.status.updatedAt,
    };

    const vacancy = this.vacancyMapper.toDomain(prismaApplication.vacancy);
    if (!vacancy) {
      throw new Error("Vacancy is required for Application");
    }

    const cv = prismaApplication.cv
      ? cvMapper.toDomain(prismaApplication.cv)
      : null;

    return new Application(
      prismaApplication.id,
      prismaApplication.userId,
      prismaApplication.profileId,
      vacancy,
      prismaApplication.statusId,
      status,
      prismaApplication.appliedAt,
      prismaApplication.createdAt,
      prismaApplication.updatedAt,
      cv,
      prismaApplication.coverLetter ?? undefined,
    );
  }

  mapToDomainWithRelations(
    prismaApplications: PrismaApplicationWithRelations[],
  ): Application[] {
    return prismaApplications
      .map((application) => this.toDomain(application))
      .filter(
        (application): application is Application => application !== null,
      );
  }
}