import { BadRequestException, HttpException, NotFoundException } from '@nestjs/common';
import { beforeEach, describe, expect, it, vi } from 'vitest';
import { FavoritesService } from './favorites.service';
import { forTenant } from '../prisma/prisma-tenant.extension';

/**
 * FavoritesService.spec — NEU (260911-gwh). Der Bereich `favorites` hatte
 * VOR diesem Lauf KEINE Testdatei fuer den Dienst (Befund J; nur
 * `icon-discovery.service.spec.ts` existierte). Zwei-Klienten-Nachbau
 * (Muster `dkv.service.spec.ts`/`auth.service.spec.ts`): `forTenant()` wird
 * auf `unboundClient.__makeBoundClient(tenantId)` umgeleitet. Der
 * UNGEBUNDENE Nachbau (der Fake selbst) hat KEINES der Anfrage-Modelle
 * (`favoriteLink`, `widgetInstance`) — ein versehentlich ungebundener
 * Modellzugriff scheitert mit "Cannot read properties of undefined" (die
 * dkv-Form der Falsifizierung, siehe auth.service.spec.ts:280). Der
 * GEBUNDENE Klient hat ausschliesslich `favoriteLink`/`widgetInstance`.
 */
vi.mock('../prisma/prisma-tenant.extension', () => ({
  forTenant: vi.fn((unboundClient: any, tenantId: string) => unboundClient.__makeBoundClient(tenantId)),
}));

interface FakeFavoriteRow {
  id: string;
  userId: string;
  tenantId: string;
  widgetId: string;
  title: string;
  url: string;
  iconUrl: string | null;
  position: number;
  createdAt?: Date;
  updatedAt?: Date;
}

interface FakeWidgetRow {
  id: string;
  userId: string;
  tenantId: string;
}

interface BoundCall {
  tenantId: string;
  model: 'favoriteLink' | 'widgetInstance';
  method: string;
}

function throwP2025(action: 'update' | 'delete'): never {
  const err: any = new Error(
    action === 'update'
      ? 'An operation failed because it depends on one or more records that were required but not found. No record was found for an update.'
      : 'An operation failed because it depends on one or more records that were required but not found. No record was found for a delete.',
  );
  err.code = 'P2025';
  throw err;
}

/**
 * Zwei-Klienten-Nachbau: `favorites`/`widgets` sind das gemeinsame
 * Gedaechtnis, der gebundene Klient (`__makeBoundClient`) protokolliert
 * jeden Zugriff im `boundCallLog` — der ungebundene Basisclient (der Fake
 * selbst) traegt KEIN `favoriteLink`/`widgetInstance` und protokolliert
 * deshalb strukturell nie.
 */
function makeFakePrisma(favoriteRows: FakeFavoriteRow[] = [], widgetRows: FakeWidgetRow[] = []) {
  const favorites = new Map(favoriteRows.map((f) => [f.id, { ...f }]));
  const widgets = new Map(widgetRows.map((w) => [w.id, { ...w }]));
  const boundCallLog: BoundCall[] = [];
  let autoId = favoriteRows.length;

  function makeScopedFavoriteLink(tenantId: string) {
    return {
      findMany: async ({ where, orderBy }: any) => {
        boundCallLog.push({ tenantId, model: 'favoriteLink', method: 'findMany' });
        let rows = Array.from(favorites.values()).filter((f) => f.tenantId === tenantId);
        if (where?.userId) rows = rows.filter((f) => f.userId === where.userId);
        if (where?.widgetId) rows = rows.filter((f) => f.widgetId === where.widgetId);
        if (orderBy) {
          rows = [...rows].sort((a, b) => {
            for (const clause of orderBy) {
              const [key, dir] = Object.entries(clause as Record<string, string>)[0];
              const av = (a as any)[key];
              const bv = (b as any)[key];
              if (av < bv) return dir === 'asc' ? -1 : 1;
              if (av > bv) return dir === 'asc' ? 1 : -1;
            }
            return 0;
          });
        }
        return rows;
      },
      findUnique: async ({ where }: any) => {
        boundCallLog.push({ tenantId, model: 'favoriteLink', method: 'findUnique' });
        const row = favorites.get(where.id);
        if (!row || row.tenantId !== tenantId) return null;
        return { ...row };
      },
      create: async ({ data }: any) => {
        boundCallLog.push({ tenantId, model: 'favoriteLink', method: 'create' });
        const id = data.id ?? `fav-${++autoId}`;
        const now = new Date();
        const record = { iconUrl: null, position: 0, createdAt: now, updatedAt: now, ...data, id };
        favorites.set(id, record);
        return record;
      },
      update: async ({ where, data }: any) => {
        boundCallLog.push({ tenantId, model: 'favoriteLink', method: 'update' });
        const row = favorites.get(where.id);
        if (!row || row.tenantId !== tenantId) throwP2025('update');
        const updated = { ...row, ...data, updatedAt: new Date() };
        favorites.set(where.id, updated);
        return updated;
      },
      delete: async ({ where }: any) => {
        boundCallLog.push({ tenantId, model: 'favoriteLink', method: 'delete' });
        const row = favorites.get(where.id);
        if (!row || row.tenantId !== tenantId) throwP2025('delete');
        favorites.delete(where.id);
        return row;
      },
    };
  }

  function makeScopedWidgetInstance(tenantId: string) {
    return {
      findUnique: async ({ where, select }: any) => {
        boundCallLog.push({ tenantId, model: 'widgetInstance', method: 'findUnique' });
        const row = widgets.get(where.id);
        if (!row || row.tenantId !== tenantId) return null;
        if (!select) return { ...row };
        const picked: any = {};
        for (const key of Object.keys(select)) {
          if (select[key]) picked[key] = (row as any)[key];
        }
        return picked;
      },
    };
  }

  const fake: any = {
    __favorites: favorites,
    __widgets: widgets,
    __boundCallLog: boundCallLog,
    __makeBoundClient(tenantId: string) {
      return {
        favoriteLink: makeScopedFavoriteLink(tenantId),
        widgetInstance: makeScopedWidgetInstance(tenantId),
      };
    },
  };
  return fake;
}

function expectBoundCall(
  prisma: any,
  tenantId: string,
  model: 'favoriteLink' | 'widgetInstance',
  method: string,
) {
  const found = prisma.__boundCallLog.some(
    (c: BoundCall) => c.tenantId === tenantId && c.model === model && c.method === method,
  );
  expect(
    found,
    `erwarteter gebundener Aufruf ${model}.${method}(tenant=${tenantId}) fehlt im Protokoll: ${JSON.stringify(prisma.__boundCallLog)}`,
  ).toBe(true);
}

function makeIconDiscovery(
  overrides: Partial<{ discoverFavoriteIconUrl: any; fetchIconBytes: any }> = {},
) {
  return {
    discoverFavoriteIconUrl:
      overrides.discoverFavoriteIconUrl ??
      vi.fn(async (url: string) => `https://icons.invalid/${encodeURIComponent(url)}`),
    fetchIconBytes:
      overrides.fetchIconBytes ??
      vi.fn(async () => ({ contentType: 'image/png', body: Buffer.from('png') })),
  };
}

beforeEach(() => {
  vi.clearAllMocks();
});

describe('FavoritesService — Bindung an forTenant() (260911-gwh)', () => {
  it('scheitert an "Cannot read properties of undefined", wenn ein Favoritenzugriff versehentlich ungebunden auf dem Basisclient laeuft (Falsifizierungsform)', () => {
    const prisma = makeFakePrisma();
    expect(prisma.favoriteLink).toBeUndefined();
    expect(prisma.widgetInstance).toBeUndefined();
  });

  describe('list', () => {
    it('liefert nur die Zeilen von user-a1 fuer widget-a1, sortiert nach position, dann title', async () => {
      const prisma = makeFakePrisma([
        { id: 'f1', userId: 'user-a1', tenantId: 't1', widgetId: 'widget-a1', title: 'B', url: 'https://b.invalid', iconUrl: null, position: 1 },
        { id: 'f2', userId: 'user-a1', tenantId: 't1', widgetId: 'widget-a1', title: 'A', url: 'https://a.invalid', iconUrl: null, position: 0 },
        { id: 'f3', userId: 'user-a2', tenantId: 't1', widgetId: 'widget-a1', title: 'C', url: 'https://c.invalid', iconUrl: null, position: 0 },
        { id: 'f4', userId: 'user-a1', tenantId: 't1', widgetId: 'widget-a2', title: 'D', url: 'https://d.invalid', iconUrl: null, position: 0 },
      ]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      const result = await service.list('t1', 'user-a1', 'widget-a1');

      expect(result.map((r: any) => r.id)).toEqual(['f2', 'f1']);
      expectBoundCall(prisma, 't1', 'favoriteLink', 'findMany');
    });

    it('liefert unter einem FREMDEN Mandanten eine leere Liste, kein Fehler (der Wert, aus dem das Widget "Noch keine Favoriten." macht)', async () => {
      const prisma = makeFakePrisma([
        { id: 'f1', userId: 'user-a1', tenantId: 't1', widgetId: 'widget-a1', title: 'B', url: 'https://b.invalid', iconUrl: null, position: 0 },
      ]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      const result = await service.list('t2', 'user-a1', 'widget-a1');

      expect(result).toEqual([]);
    });

    it('wirft BadRequestException ohne widgetId, OHNE einen Klienten zu erzeugen', async () => {
      const prisma = makeFakePrisma();
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.list('t1', 'user-a1', '')).rejects.toThrow(BadRequestException);
      expect(vi.mocked(forTenant).mock.calls.length).toBe(0);
    });
  });

  describe('create', () => {
    it('normalisiert die URL, sucht das Icon mit der NORMALISIERTEN URL, und legt mit tenantId/userId/widgetId/position=0 an, wenn iconUrl fehlt', async () => {
      const prisma = makeFakePrisma([], [{ id: 'widget-a1', userId: 'user-a1', tenantId: 't1' }]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      const created = await service.create('t1', 'user-a1', {
        widgetId: 'widget-a1',
        title: 'CTL',
        url: 'ctl.de',
      } as any);

      expect(iconDiscovery.discoverFavoriteIconUrl).toHaveBeenCalledWith('https://ctl.de');
      expect(created.url).toBe('https://ctl.de');
      expect(created.userId).toBe('user-a1');
      expect(created.tenantId).toBe('t1');
      expect(created.position).toBe(0);
      expectBoundCall(prisma, 't1', 'favoriteLink', 'create');
    });

    it('sucht KEIN Icon, wenn iconUrl uebergeben wird — gespeicherter Wert bleibt wie uebergeben', async () => {
      const prisma = makeFakePrisma([], [{ id: 'widget-a1', userId: 'user-a1', tenantId: 't1' }]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      const created = await service.create('t1', 'user-a1', {
        widgetId: 'widget-a1',
        title: 'CTL',
        url: 'https://ctl.de',
        iconUrl: 'https://ctl.de/favicon.ico',
      } as any);

      expect(iconDiscovery.discoverFavoriteIconUrl).not.toHaveBeenCalled();
      expect(created.iconUrl).toBe('https://ctl.de/favicon.ico');
    });

    it('T-GWH-05: widgetId gehoert einem ANDEREN Benutzer desselben Mandanten -> NotFoundException "Widget not found", KEIN create, KEINE Icon-Suche', async () => {
      const prisma = makeFakePrisma([], [{ id: 'widget-a2', userId: 'user-a2', tenantId: 't1' }]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      await expect(
        service.create('t1', 'user-a1', { widgetId: 'widget-a2', title: 'X', url: 'https://x.invalid' } as any),
      ).rejects.toThrow('Widget not found');
      expect(iconDiscovery.discoverFavoriteIconUrl).not.toHaveBeenCalled();
      expect(prisma.__favorites.size).toBe(0);
    });

    it('T-GWH-05: widgetId gehoert einem Widget unter FREMDEM Mandanten -> dieselbe NotFoundException, nennt weder Halter noch Mandant', async () => {
      const prisma = makeFakePrisma([], [{ id: 'widget-b1', userId: 'user-b1', tenantId: 't2' }]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(
        service.create('t1', 'user-a1', { widgetId: 'widget-b1', title: 'X', url: 'https://x.invalid' } as any),
      ).rejects.toThrow(NotFoundException);
      await expect(
        service.create('t1', 'user-a1', { widgetId: 'widget-b1', title: 'X', url: 'https://x.invalid' } as any),
      ).rejects.toThrow('Widget not found');
    });

    it('T-GWH-05: unbekannte widgetId -> dieselbe NotFoundException', async () => {
      const prisma = makeFakePrisma();
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(
        service.create('t1', 'user-a1', { widgetId: 'widget-fehlt', title: 'X', url: 'https://x.invalid' } as any),
      ).rejects.toThrow('Widget not found');
    });

    it('Wachhund: genau EIN gebundener Klient je create-Aufruf, Widget-Pruefung UND Schreibzugriff auf DEMSELBEN Klienten', async () => {
      const prisma = makeFakePrisma([], [{ id: 'widget-a1', userId: 'user-a1', tenantId: 't1' }]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      vi.mocked(forTenant).mockClear();
      await service.create('t1', 'user-a1', { widgetId: 'widget-a1', title: 'X', url: 'https://x.invalid' } as any);

      expect(vi.mocked(forTenant).mock.calls.length).toBe(1);
      expect(prisma.__boundCallLog.filter((c: BoundCall) => c.tenantId === 't1')).toEqual([
        { tenantId: 't1', model: 'widgetInstance', method: 'findUnique' },
        { tenantId: 't1', model: 'favoriteLink', method: 'create' },
      ]);
    });
  });

  describe('update', () => {
    const baseRow: FakeFavoriteRow = {
      id: 'f1',
      userId: 'user-a1',
      tenantId: 't1',
      widgetId: 'widget-a1',
      title: 'Alt',
      url: 'https://alt.invalid',
      iconUrl: 'https://alt.invalid/icon.png',
      position: 0,
    };

    it('mergt Titel/URL/Position fuer die eigene Zeile, ueber DEMSELBEN gebundenen Klienten', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      const updated = await service.update('t1', 'f1', 'user-a1', { title: 'Neu', position: 3 } as any);

      expect(updated.title).toBe('Neu');
      expect(updated.position).toBe(3);
      expectBoundCall(prisma, 't1', 'favoriteLink', 'findUnique');
      expectBoundCall(prisma, 't1', 'favoriteLink', 'update');
    });

    it('iconUrl explizit null im DTO loest eine Icon-Suche gegen die EFFEKTIVE URL aus', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      await service.update('t1', 'f1', 'user-a1', { iconUrl: null } as any);

      expect(iconDiscovery.discoverFavoriteIconUrl).toHaveBeenCalledWith(baseRow.url);
    });

    it('iconUrl gesetzt im DTO -> KEINE Icon-Suche', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      const updated = await service.update('t1', 'f1', 'user-a1', { iconUrl: 'https://neu.invalid/icon.png' } as any);

      expect(iconDiscovery.discoverFavoriteIconUrl).not.toHaveBeenCalled();
      expect(updated.iconUrl).toBe('https://neu.invalid/icon.png');
    });

    it('Zeile eines ANDEREN Benutzers desselben Mandanten -> NotFoundException, KEIN Schreibzugriff', async () => {
      const prisma = makeFakePrisma([{ ...baseRow, userId: 'user-a2' }]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.update('t1', 'f1', 'user-a1', { title: 'X' } as any)).rejects.toThrow(
        'FavoriteLink not found',
      );
      expect(prisma.__favorites.get('f1')?.title).toBe('Alt');
    });

    it('Zeile unter FREMDEM Mandanten -> NotFoundException, KEIN Schreibzugriff — der gebundene findUnique liefert null, bevor irgendetwas geschrieben wird', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.update('t2', 'f1', 'user-a1', { title: 'X' } as any)).rejects.toThrow(
        NotFoundException,
      );
      expect(prisma.__favorites.get('f1')?.title).toBe('Alt');
      expect(
        prisma.__boundCallLog.some((c: BoundCall) => c.tenantId === 't2' && c.method === 'update'),
      ).toBe(false);
    });
  });

  describe('remove', () => {
    const baseRow: FakeFavoriteRow = {
      id: 'f1',
      userId: 'user-a1',
      tenantId: 't1',
      widgetId: 'widget-a1',
      title: 'X',
      url: 'https://x.invalid',
      iconUrl: null,
      position: 0,
    };

    it('loescht die eigene Zeile', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await service.remove('t1', 'f1', 'user-a1');

      expect(prisma.__favorites.has('f1')).toBe(false);
    });

    it('fremder Benutzer -> NotFoundException, Zeile bleibt', async () => {
      const prisma = makeFakePrisma([{ ...baseRow, userId: 'user-a2' }]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.remove('t1', 'f1', 'user-a1')).rejects.toThrow('FavoriteLink not found');
      expect(prisma.__favorites.has('f1')).toBe(true);
    });

    it('fremder Mandant -> NotFoundException, Zeile bleibt', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.remove('t2', 'f1', 'user-a1')).rejects.toThrow(NotFoundException);
      expect(prisma.__favorites.has('f1')).toBe(true);
    });
  });

  describe('getIconBytes', () => {
    const baseRow: FakeFavoriteRow = {
      id: 'f1',
      userId: 'user-a1',
      tenantId: 't1',
      widgetId: 'widget-a1',
      title: 'X',
      url: 'https://x.invalid',
      iconUrl: 'https://x.invalid/icon.png',
      position: 0,
    };

    it('ruft fetchIconBytes GENAU mit der GESPEICHERTEN URL auf und reicht die Rueckgabe durch', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      const result = await service.getIconBytes('t1', 'f1', 'user-a1');

      expect(iconDiscovery.fetchIconBytes).toHaveBeenCalledWith(baseRow.iconUrl);
      expect(result).toEqual({ contentType: 'image/png', body: Buffer.from('png') });
    });

    it('Zeile ohne iconUrl -> NotFoundException, fetchIconBytes NICHT aufgerufen', async () => {
      const prisma = makeFakePrisma([{ ...baseRow, iconUrl: null }]);
      const iconDiscovery = makeIconDiscovery();
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      await expect(service.getIconBytes('t1', 'f1', 'user-a1')).rejects.toThrow('FavoriteLink not found');
      expect(iconDiscovery.fetchIconBytes).not.toHaveBeenCalled();
    });

    it('fremder Mandant -> NotFoundException', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      await expect(service.getIconBytes('t2', 'f1', 'user-a1')).rejects.toThrow(NotFoundException);
    });

    it('fetchIconBytes wirft -> HttpException mit Status 502', async () => {
      const prisma = makeFakePrisma([baseRow]);
      const iconDiscovery = makeIconDiscovery({
        fetchIconBytes: vi.fn(async () => {
          throw new Error('upstream unreachable');
        }),
      });
      const service = new FavoritesService(prisma as any, iconDiscovery as any);

      await expect(service.getIconBytes('t1', 'f1', 'user-a1')).rejects.toThrow(HttpException);
      try {
        await service.getIconBytes('t1', 'f1', 'user-a1');
      } catch (err) {
        expect((err as HttpException).getStatus()).toBe(502);
      }
    });
  });

  describe('Wachhund je Methode', () => {
    it('genau EIN gebundener Klient je Aufruf von list/update/remove/getIconBytes', async () => {
      const baseRow: FakeFavoriteRow = {
        id: 'f1',
        userId: 'user-a1',
        tenantId: 't1',
        widgetId: 'widget-a1',
        title: 'X',
        url: 'https://x.invalid',
        iconUrl: 'https://x.invalid/icon.png',
        position: 0,
      };
      const prisma = makeFakePrisma([baseRow]);
      const service = new FavoritesService(prisma as any, makeIconDiscovery() as any);

      for (const call of [
        () => service.list('t1', 'user-a1', 'widget-a1'),
        () => service.update('t1', 'f1', 'user-a1', { title: 'Y' } as any),
        () => service.getIconBytes('t1', 'f1', 'user-a1'),
        () => service.remove('t1', 'f1', 'user-a1'),
      ]) {
        vi.mocked(forTenant).mockClear();
        await call().catch(() => undefined);
        expect(
          vi.mocked(forTenant).mock.calls.length,
          `Aufruf erzeugte ${vi.mocked(forTenant).mock.calls.length} gebundene Klienten, erwartet genau 1`,
        ).toBe(1);
      }
    });
  });
});