import { Injectable } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';

/**
 * Service for managing the per-user Tender digest interval preference
 * (NOTIFY-01, D-01/D-03).
 *
 * Access control (T-12-14 / V4 — IDOR): scoped by userId exactly like
 * TenderSavedSearchService/TenderTriageService (T-11-14/T-08-06) — NOT
 * forTenant()/RLS (Pitfall 4). userId must always be derived from the
 * caller's auth context (controller), never accepted as a body/query
 * parameter here.
 *
 * `TenderNotificationPref` has a per-user `@@unique` on `userId` (one row
 * per user, D-03: the interval is a user setting, not per-profile) — this
 * service upserts on that key.
 */
@Injectable()
export class TenderNotificationPrefService {
  constructor(private readonly prisma: PrismaService) {}

  /**
   * Returns this user's digest interval preference. When no row exists yet
   * (user has never touched the setting), returns the default
   * `{ digestInterval: 'daily' }` (D-01) WITHOUT writing a row — consistent
   * with the digest scheduler's own default-daily due-check semantics, no
   * autowrite needed to represent "using the default".
   */
  async getForUser(userId: string): Promise<{ digestInterval: string }> {
    const existing = await this.prisma.tenderNotificationPref.findUnique({
      where: { userId },
    });

    if (!existing) {
      return { digestInterval: 'daily' };
    }

    return existing;
  }

  /**
   * Upserts this user's digest interval preference on the @@unique userId
   * (D-03) — a second call for the same user updates the same row rather
   * than creating a new one.
   */
  async setForUser(userId: string, tenantId: string, digestInterval: string) {
    return this.prisma.tenderNotificationPref.upsert({
      where: { userId },
      create: { userId, tenantId, digestInterval },
      update: { digestInterval },
    });
  }
}