import { Injectable } from '@nestjs/common';
import type { SourceType } from './tender.types';
import type { TenderSourceAdapter } from './adapters/tender-source-adapter.interface';

/**
 * Portals whose AGB (Nutzungsbedingungen) prohibit automated/scraping
 * access (INGEST-07/D-06). This is the hard code boundary — NOT just
 * documentation: `SourceRegistry.register()` checks every adapter's
 * `portals` against this list and refuses registration outright if any
 * entry matches, at DI-boot time, before any poll can run.
 */
export const DENYLISTED_PORTALS = ['vergabe24', 'aumass'] as const;

/**
 * Canonical direct-link URL per denylisted portal (UI-06/D-12). Keyed by
 * the same portal slugs as `DENYLISTED_PORTALS` — the portal SET is never
 * re-declared here, only the URL each already-listed portal maps to.
 * `TendersController.getDenylistedPortals()` maps over `DENYLISTED_PORTALS`
 * and looks up each entry's URL here, so a future denylist addition needs
 * only a URL added to this map (not a second hardcoded list anywhere else).
 */
export const PORTAL_URLS: Record<(typeof DENYLISTED_PORTALS)[number], string> = {
  vergabe24: 'https://www.vergabe24.de',
  aumass: 'https://www.aumass.de',
};

/**
 * Thrown by `SourceRegistry.register()` when an adapter declares a
 * denylisted portal. Proves Erfolgskriterium 4 (13-CONTEXT.md D-06) —
 * see source-registry.spec.ts.
 */
export class DeniedPortalError extends Error {
  constructor(portal: string) {
    super(
      `Portal '${portal}' ist AGB-seitig für automatisierten Zugriff gesperrt und darf nicht registriert werden.`,
    );
    this.name = 'DeniedPortalError';
  }
}

/**
 * Central registry mapping `SourceType` -> `TenderSourceAdapter`, gated by
 * the AGB denylist (T-13-02-01/T-13-02-02). `pollDueSources` (Plan 13-03)
 * uses `get()`/`activeAdapters()` to fan out over all registered sources
 * (poll-once-fan-out-many) instead of hardwiring a single adapter.
 */
@Injectable()
export class SourceRegistry {
  private readonly adapters = new Map<SourceType, TenderSourceAdapter>();

  /**
   * Registers an adapter. Iterates ALL of the adapter's declared `portals`
   * — a single denylisted entry rejects the whole adapter, even if the
   * rest of its portals are legitimate (T-13-02-02: no partial/mixed
   * registration).
   */
  register(adapter: TenderSourceAdapter): void {
    for (const portal of adapter.portals) {
      if ((DENYLISTED_PORTALS as readonly string[]).includes(portal)) {
        throw new DeniedPortalError(portal);
      }
    }
    this.adapters.set(adapter.sourceType, adapter);
  }

  /** Returns the adapter for a sourceType, or undefined if none is registered — never throws. */
  get(type: SourceType): TenderSourceAdapter | undefined {
    return this.adapters.get(type);
  }

  /** All currently registered adapters, for fan-out scheduling. */
  activeAdapters(): TenderSourceAdapter[] {
    return [...this.adapters.values()];
  }
}