import { BadRequestException, Injectable, NotFoundException } from "@nestjs/common";
import { resellersRepo, usersRepo, auditRepo, type Reseller } from "@eden/database";
import { onlyDigits, isValidCPF, isValidCNPJ } from "@eden/domain-shared";
import type { CreateResellerDto } from "./dto/create-reseller.dto.js";
import type { UpdateResellerDto } from "./dto/update-reseller.dto.js";
import type { AssignUserToResellerDto } from "./dto/assign-user-to-reseller.dto.js";

@Injectable()
export class ResellersService {
  list(includeInactive: boolean): Promise<Reseller[]> {
    return resellersRepo.listResellers(includeInactive);
  }

  async get(id: string): Promise<Reseller> {
    const reseller = await resellersRepo.getResellerById(id);
    if (!reseller) throw new NotFoundException("Revenda não encontrada");
    return reseller;
  }

  async create(dto: CreateResellerDto, actorId: string): Promise<Reseller> {
    this.assertValidDocumentIfPresent(dto.document);

    const reseller = await resellersRepo.createReseller({
      name: dto.name,
      document: dto.document ? onlyDigits(dto.document) : undefined,
      contactEmail: dto.contactEmail,
      active: dto.active,
      createdBy: actorId,
    });

    await auditRepo.appendAuditEvent({
      actorType: "user",
      actorId,
      action: "reseller.created",
      resourceType: "reseller",
      resourceId: reseller.id,
    });

    return reseller;
  }

  async update(id: string, dto: UpdateResellerDto, actorId: string): Promise<Reseller> {
    await this.get(id); // 404 if missing
    this.assertValidDocumentIfPresent(dto.document);

    const reseller = await resellersRepo.updateReseller(id, {
      name: dto.name,
      document: dto.document ? onlyDigits(dto.document) : undefined,
      contactEmail: dto.contactEmail,
      active: dto.active,
    });
    if (!reseller) throw new NotFoundException("Revenda não encontrada");

    await auditRepo.appendAuditEvent({
      actorType: "user",
      actorId,
      action: "reseller.updated",
      resourceType: "reseller",
      resourceId: id,
      metadata: { fields: Object.keys(dto) },
    });

    return reseller;
  }

  /** Always assigns to the reseller identified by the URL `:id` — see the DTO's comment for why that's now the only source of truth. */
  async assignUser(
    id: string,
    dto: AssignUserToResellerDto,
    actorId: string,
  ): Promise<{ userId: string; resellerId: string }> {
    await this.get(id); // 404 if the reseller doesn't exist

    const found = await usersRepo.assignUserToReseller(dto.userId, id);
    if (!found) throw new NotFoundException("Usuário não encontrado");

    await auditRepo.appendAuditEvent({
      actorType: "user",
      actorId,
      action: "reseller.user_assigned",
      resourceType: "user",
      resourceId: dto.userId,
      metadata: { resellerId: id },
    });

    return { userId: dto.userId, resellerId: id };
  }

  /** Clears a user's reseller assignment (sets `reseller_id = null`) — not scoped to any particular reseller's URL, since "no reseller" isn't a reseller. */
  async unassignUser(userId: string, actorId: string): Promise<{ userId: string; resellerId: null }> {
    const found = await usersRepo.assignUserToReseller(userId, null);
    if (!found) throw new NotFoundException("Usuário não encontrado");

    await auditRepo.appendAuditEvent({
      actorType: "user",
      actorId,
      action: "reseller.user_unassigned",
      resourceType: "user",
      resourceId: userId,
    });

    return { userId, resellerId: null };
  }

  /** Mirrors Companies' assertValidCnpjIfPresent — document is CPF or CNPJ here. */
  private assertValidDocumentIfPresent(document: string | undefined): void {
    if (!document) return;
    const digits = onlyDigits(document);
    const valid =
      digits.length === 11 ? isValidCPF(digits) : digits.length === 14 ? isValidCNPJ(digits) : false;
    if (!valid) {
      throw new BadRequestException("CPF/CNPJ inválido");
    }
  }
}