import { ConflictException, Injectable } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';
import { forTenant } from '../prisma/prisma-tenant.extension';

/**
 * 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). This
 * stays deliberate belt-and-suspenders after binding to `forTenant()`
 * (260909-laa) — the delivered policy on TenderNotificationPref has no
 * user dimension (Befund E, Aufgabe 1).
 *
 * `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.
 *
 * T-LAA-07 (260909-laa, Befund F): `userId` has no tenant dimension. If a
 * user's stored `tenantId` has gone stale (their resolved tenant changed)
 * the existing row can become invisible under the now-bound context — a
 * bound `upsert` then falls into the create branch and hits the
 * platform-wide uniqueness constraint on `userId`. Aufgabe 1 measured this
 * exact shape for the sibling `TenderTriage` upsert
 * (`tendertriage-einfuegen-auf-unsichtbare-zeile-verletzt-eindeutigkeit`):
 * the failure is a P2002 unique-constraint violation, not an RLS
 * rejection. Translated below into a German message, same pattern as
 * `tender-saved-search.service.ts`, instead of surfacing as a raw 500.
 *
 * Nachtrag (260911-nke, Etappe 3b): seit Migration 20260911120000 traegt
 * die Regel auf TenderNotificationPref die Benutzerdimension
 * (`current_user_id() IS NULL OR "userId" = current_user_id()`) — beide
 * `forTenant()`-Aufrufe unten reichen `userId` als drittes Argument durch.
 * Die anwendungsseitige userId-Filterung bleibt zweites Netz, kein Ersatz.
 */
@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, tenantId: string): Promise<{ digestInterval: string }> {
    const tenantPrisma = forTenant(this.prisma, tenantId, userId);
    const existing = await tenantPrisma.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) {
    const tenantPrisma = forTenant(this.prisma, tenantId, userId);
    try {
      return await tenantPrisma.tenderNotificationPref.upsert({
        where: { userId },
        create: { userId, tenantId, digestInterval },
        update: { digestInterval },
      });
    } catch (error: any) {
      if (error?.code === 'P2002') {
        throw new ConflictException(
          'Die Benachrichtigungseinstellung konnte nicht gespeichert werden, weil bereits ein widersprüchlicher Eintrag existiert. Bitte laden Sie die Seite neu und versuchen Sie es erneut.',
        );
      }
      throw error;
    }
  }
}