import type { Prisma } from '@generated/prisma/client';
import type {
  GroupList,
  GroupQuery,
  ProblemDetails,
  Result,
} from '@gruperly/shared';
import { ok } from '@gruperly/shared';
import { getPaginationMetadata, getPaginationOffset } from '@/lib/pagination';
import prisma from '@/lib/prisma';
import {
  buildGroupWhereForUser,
  type GroupDb,
  type GroupRecord,
  toGroupDto,
} from '../../lib';

type ListGroupsDeps = {
  db?: Pick<GroupDb, 'group'>;
};

export class ListGroups {
  constructor(private readonly deps: ListGroupsDeps = {}) {}

  async execute(
    query: GroupQuery,
    userId: string,
  ): Promise<Result<GroupList, ProblemDetails>> {
    const db = this.deps.db ?? prisma;
    const where = buildGroupWhereForUser(userId) as Prisma.GroupWhereInput;

    const [records, total] = await Promise.all([
      db.group.findMany({
        where,
        skip: getPaginationOffset(query),
        take: query.pageSize,
        orderBy: { createdAt: 'desc' },
      }),
      db.group.count({ where }),
    ]);

    return ok({
      data: records.map((record: GroupRecord) => toGroupDto(record)),
      pagination: getPaginationMetadata(query, total),
    });
  }
}