/**
 * iam Role Resolver（v2.1 M1）
 *
 * Apollo Federation 子图：Role Entity
 * - @key(fields: "roleId") 支持跨子图引用
 * - @ResolveReference 使用 DataLoader 批量加载（ADR-035）
 */
import {
  Resolver,
  Query,
  Args,
  ID,
  ResolveReference,
  ObjectType,
  Field,
  Directive,
} from "@nestjs/graphql";
import { DataLoaderService, type RoleEntity } from "../dataloader.service.js";
import {
  Permissions,
  RequirePermission,
} from "../../middleware/permission.guard.js";

@ObjectType()
@Directive(`@key(fields: "roleId")`)
export class Role {
  @Field(() => ID)
  roleId!: string;

  @Field()
  name!: string;

  @Field(() => String, { nullable: true })
  description: string | null = null;

  @Field()
  roleType!: string;

  @Field()
  level!: number;
}

@Resolver(() => Role)
export class RoleResolver {
  constructor(private readonly loader: DataLoaderService) {}

  @ResolveReference()
  async resolveReference(ref: { roleId: string }): Promise<RoleEntity | null> {
    return this.loader.roleLoader.load(ref.roleId);
  }

  @Query(() => Role, { nullable: true })
  @RequirePermission(Permissions.IAM_USER_READ)
  async role(
    @Args("roleId", { type: () => ID }) roleId: string,
  ): Promise<RoleEntity | null> {
    return this.loader.roleLoader.load(roleId);
  }
}