import { Injectable, NotFoundException } from "@nestjs/common";
import { InjectRepository } from "@nestjs/typeorm";
import { Repository } from "typeorm";
import { CredentialEntity } from "./credential.entity";
import { CreateCredentialDto } from "./dto/create-credential.dto";
import { UpdateCredentialDto } from "./dto/update-credential.dto";
import { CredentialExportDto } from "./dto/credential-export.dto";
import {
  PaginationQueryDto,
  PaginatedResult,
} from "../common/dto/pagination.dto";

export type CredentialOrderBy = "id" | "name" | "lastUsedAt" | "createdAt" | "updatedAt";

@Injectable()
export class CredentialService {
  constructor(
    @InjectRepository(CredentialEntity)
    private readonly repo: Repository<CredentialEntity>,
  ) {}

  async create(dto: CreateCredentialDto): Promise<CredentialEntity> {
    return this.repo.save(this.repo.create({ ...dto, data: dto.data ?? null }));
  }

  async findAll(
    query: PaginationQueryDto<CredentialOrderBy> = {},
  ): Promise<PaginatedResult<CredentialEntity>> {
    const page = query.page ?? 1;
    const limit = query.limit ?? 20;
    const orderBy = query.orderBy ?? "id";
    const orderDir = query.orderDir ?? "ASC";
    const [data, total] = await this.repo.findAndCount({
      order: { [orderBy]: orderDir },
      skip: (page - 1) * limit,
      take: limit,
    });
    return { data, total, page, limit };
  }

  async findOne(id: string): Promise<CredentialEntity> {
    const credential = await this.repo.findOneBy({ id });
    if (!credential) throw new NotFoundException(`Credential ${id} not found`);
    return credential;
  }

  async update(id: string, dto: UpdateCredentialDto): Promise<CredentialEntity> {
    const credential = await this.findOne(id);
    Object.assign(credential, dto);
    return this.repo.save(credential);
  }

  async remove(id: string): Promise<void> {
    await this.findOne(id);
    await this.repo.delete(id);
  }

  exportCredential(credential: CredentialEntity): CredentialExportDto {
    return { kind: "credential", id: credential.id, name: credential.name, data: credential.data };
  }

  async importCredential(dto: CredentialExportDto): Promise<CredentialEntity> {
    if (dto.id) {
      const existing = await this.repo.findOneBy({ id: dto.id });
      if (existing) {
        Object.assign(existing, { name: dto.name, data: dto.data ?? null });
        return this.repo.save(existing);
      }
      return this.repo.save(
        this.repo.create({ id: dto.id, name: dto.name, data: dto.data ?? null }),
      );
    }
    return this.repo.save(
      this.repo.create({ name: dto.name, data: dto.data ?? null }),
    );
  }
}