import type { PrismaClient } from '@generated/prisma/client';
import type {
  ProblemDetails,
  Result,
  UpdateStudentStatus,
  UpdateStudentStatusResult,
} from '@gruperly/shared';
import { err, ok } from '@gruperly/shared';
import { noGroupAccessProblem, notFoundResourceProblem } from '@/http/problem-builders';
import prisma from '@/lib/prisma';

type UpdateAttendeeStatusDeps = {
  db?: Pick<PrismaClient, 'attendee'>;
};

export class UpdateAttendeeStatus {
  constructor(private readonly deps: UpdateAttendeeStatusDeps = {}) {}

  async execute(
    studentId: string,
    userId: string,
    payload: UpdateStudentStatus,
  ): Promise<Result<UpdateStudentStatusResult, ProblemDetails>> {
    const db = this.deps.db ?? prisma;

    const attendee = await db.attendee.findUnique({
      where: { id: studentId },
      include: { group: { include: { members: { where: { userId } } } } },
    });

    if (!attendee) {
      return err(notFoundResourceProblem('Attendee', studentId));
    }

    const isOwner = attendee.group.createdById === userId;
    const isMember = attendee.group.members.length > 0;
    if (!isOwner && !isMember) {
      return err(noGroupAccessProblem());
    }

    if (attendee.status === payload.status) {
      return ok({ attendeeId: studentId, status: payload.status });
    }

    const updated = await db.attendee.update({
      where: { id: studentId },
      data: { status: payload.status },
      select: { id: true, status: true },
    });

    return ok({ attendeeId: updated.id, status: updated.status });
  }
}