import { NextRequest, NextResponse } from 'next/server';
import { auth } from '@/auth';
import { getEffectiveTier } from '@/lib/entitlements';
import { getActiveByokKey, isByokProviderAllowed } from '@/lib/byok';
import { decryptApiKey } from '@/lib/crypto';
import { fetchLiveModelsForProvider, type FetchModelsResult } from '@/lib/ai/models-list';
import { VALID_PROVIDERS, type AiGatewayProvider } from '@/lib/ai/router';

/**
 * GET /api/user/api-keys/live-models?provider=<provider>[&key=<api_key>][&baseUrl=<url>]
 *
 * Liste les modèles chez le fournisseur. Sans clé (saisie ou déjà enregistrée) : liste vide.
 * Pas de liste de secours figée.
 */
export async function GET(request: NextRequest) {
  const session = await auth();
  if (!session?.user?.id) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const tier = await getEffectiveTier(session.user.id);
  if (tier === 'BASIC') {
    return NextResponse.json({ error: 'Forbidden' }, { status: 403 });
  }

  const { searchParams } = request.nextUrl;
  const provider = searchParams.get('provider') as AiGatewayProvider;
  let apiKey = searchParams.get('key') ?? '';
  let baseUrl = searchParams.get('baseUrl') ?? undefined;

  if (!provider) {
    return NextResponse.json({ error: 'Missing provider' }, { status: 400 });
  }

  if (!VALID_PROVIDERS.has(provider)) {
    return NextResponse.json({ error: 'Invalid provider' }, { status: 400 });
  }

  if (!isByokProviderAllowed(tier, provider)) {
    return NextResponse.json({ error: 'Tier restricted' }, { status: 403 });
  }

  if (!apiKey || apiKey.length < 4) {
    const saved = await getActiveByokKey(session.user.id, provider, tier);
    if (saved) {
      try {
        apiKey = await decryptApiKey(saved.encryptedKey);
        if (!baseUrl && saved.baseUrl) baseUrl = saved.baseUrl;
      } catch {
        apiKey = '';
      }
    }
  }

  if (!apiKey || apiKey.length < 4) {
    return NextResponse.json({ success: true, models: [], fromApi: false });
  }

  const result: FetchModelsResult = await fetchLiveModelsForProvider(provider, apiKey, baseUrl);
  return NextResponse.json({ success: true, models: result.models, fromApi: result.fromApi });
}