import { Injectable, NotFoundException } from '@nestjs/common';
import { JwtService } from '@nestjs/jwt';
import { PrismaClient } from '../prisma/prisma.module';

export interface GuestJwtPayload {
  guestId: string;
  kcId: string;
  gemeindeId: string | null;
}

/// Guest/Konfi accounts are local to this server (never Authentik-backed),
/// created via a KC invite code, and scoped to that single KC.
@Injectable()
export class GuestAuthService {
  constructor(
    private readonly prisma: PrismaClient,
    private readonly jwt: JwtService,
  ) {}

  async createGuest(
    inviteCode: string,
    firstName: string,
    lastName: string,
  ): Promise<{ accessToken: string }> {
    const kc = await this.prisma.kc.findUnique({ where: { inviteCode } });
    if (!kc || !kc.isActive) {
      throw new NotFoundException('Unknown or inactive KC invite code');
    }

    const guest = await this.prisma.guestAccount.create({
      data: { kcId: kc.id, firstName, lastName },
    });

    const payload: GuestJwtPayload = {
      guestId: guest.id,
      kcId: kc.id,
      gemeindeId: guest.gemeindeId,
    };
    return { accessToken: await this.jwt.signAsync(payload) };
  }
}