import { BadRequestException, ForbiddenException, NotFoundException } from '@nestjs/common';
import { ChatChannelType, Role } from '@prisma/client';
import { ChatService } from './chat.service';
import { AuthenticatedUser } from '../auth/authenticated-request';
import { GuestJwtPayload } from '../auth/guest-auth.service';

/// Focus: GRUPPE channel creation + participant management authorization
/// (creator / Leitungsteam / Verantwortliche/r of that KC), and read/write
/// access for team users and guests. Prisma + Sync + Push faked in memory.

function userCaller(userId: string, memberships: AuthenticatedUser['memberships']) {
  return {
    kind: 'user' as const,
    user: { userId, authentikSub: `sub-${userId}`, email: `${userId}@example.org`, memberships },
  };
}
function guestCaller(guestId: string, kcId: string, gemeindeId: string | null = null) {
  const guest: GuestJwtPayload = { guestId, kcId, gemeindeId };
  return { kind: 'guest' as const, guest };
}

const LT = userCaller('lt-1', [{ kcId: 'kc-1', gemeindeId: null, role: Role.LEITUNGSTEAM }]);
const VERANTW = userCaller('ver-1', [
  { kcId: 'kc-1', gemeindeId: 'gem-1', role: Role.GEMEINDE_VERANTWORTLICHER },
]);
const TEAMER = userCaller('teamer-1', [
  { kcId: 'kc-1', gemeindeId: 'gem-1', role: Role.GEMEINDE_TEAMER },
]);

function makeService(
  opts: {
    channels?: Record<string, any>;
    memberships?: { kcId: string; userId: string }[];
    guests?: { id: string; kcId: string }[];
  } = {},
) {
  const channels: Record<string, any> = opts.channels ?? {};
  const memberships = opts.memberships ?? [];
  const guests = opts.guests ?? [];
  const participants: any[] = [];
  let participantSeq = 0;

  const prisma = {
    chatChannel: {
      create: jest.fn(({ data, include }: any) => {
        const id = `chan-${Object.keys(channels).length + 1}`;
        const created = { id, ...data, participants: [] };
        if (data.participants?.create) {
          for (const p of data.participants.create) {
            const row = { id: `part-${++participantSeq}`, channelId: id, userId: null, guestAccountId: null, ...p };
            participants.push(row);
            created.participants.push(row);
          }
        }
        channels[id] = created;
        return Promise.resolve(include ? created : { id, ...data });
      }),
      findUnique: jest.fn(({ where, include }: any) => {
        const channel = channels[where.id];
        if (!channel) return Promise.resolve(null);
        if (include?.participants) {
          const seeded = participants.filter((p) => p.channelId === channel.id);
          const fallback = Array.isArray(channel.participants) ? channel.participants : [];
          return Promise.resolve({
            ...channel,
            participants: seeded.length ? seeded : fallback,
          });
        }
        return Promise.resolve(channel);
      }),
      findMany: jest.fn().mockResolvedValue([]),
    },
    membership: {
      findMany: jest.fn(({ where }: any) => {
        const ids: string[] = where.userId.in;
        const rows = memberships.filter((m) => m.kcId === where.kcId && ids.includes(m.userId));
        const seen = new Set<string>();
        const distinct = rows.filter((r) => (seen.has(r.userId) ? false : (seen.add(r.userId), true)));
        return Promise.resolve(distinct);
      }),
      findFirst: jest.fn(({ where }: any) =>
        Promise.resolve(memberships.find((m) => m.kcId === where.kcId && m.userId === where.userId) ?? null),
      ),
      count: jest.fn().mockResolvedValue(0),
    },
    guestAccount: {
      count: jest.fn(({ where }: any) =>
        Promise.resolve(guests.filter((g) => where.id.in.includes(g.id) && g.kcId === where.kcId).length),
      ),
      findFirst: jest.fn(({ where }: any) =>
        Promise.resolve(guests.find((g) => g.id === where.id && g.kcId === where.kcId) ?? null),
      ),
    },
    chatParticipant: {
      upsert: jest.fn(({ create }: any) => {
        const existing = participants.find(
          (p) =>
            p.channelId === create.channelId &&
            p.userId === (create.userId ?? null) &&
            p.guestAccountId === (create.guestAccountId ?? null),
        );
        if (existing) return Promise.resolve(existing);
        const row = { id: `part-${++participantSeq}`, userId: null, guestAccountId: null, ...create };
        participants.push(row);
        return Promise.resolve(row);
      }),
      findFirst: jest.fn(({ where }: any) =>
        Promise.resolve(
          participants.find(
            (p) =>
              p.channelId === where.channelId &&
              (where.userId === undefined || p.userId === where.userId) &&
              (where.guestAccountId === undefined || p.guestAccountId === where.guestAccountId),
          ) ?? null,
        ),
      ),
      delete: jest.fn(({ where }: any) => {
        const idx = participants.findIndex((p) => p.id === where.id);
        const [removed] = participants.splice(idx, 1);
        return Promise.resolve(removed);
      }),
    },
    chatMessage: { create: jest.fn(), findMany: jest.fn() },
  };
  const sync = { capture: jest.fn().mockResolvedValue(undefined) };
  const push = { notifyChannel: jest.fn().mockResolvedValue(undefined) };
  const service = new ChatService(prisma as never, sync as never, push as never);
  return { service, prisma, sync, push, channels, participants };
}

describe('ChatService.createGruppe', () => {
  it('creates a GRUPPE channel with the creator plus given team/guest participants', async () => {
    const { service, sync } = makeService({
      memberships: [{ kcId: 'kc-1', userId: 'ver-1' }, { kcId: 'kc-1', userId: 'teamer-1' }],
      guests: [{ id: 'guest-1', kcId: 'kc-1' }],
    });
    const channel = await service.createGruppe('kc-1', 'Ausflugsplanung', 'ver-1', {
      userIds: ['teamer-1'],
      guestIds: ['guest-1'],
    });
    expect(channel.type).toBe(ChatChannelType.GRUPPE);
    expect(channel.createdByUserId).toBe('ver-1');
    const userIds = channel.participants.map((p: any) => p.userId).filter(Boolean);
    const guestIds = channel.participants.map((p: any) => p.guestAccountId).filter(Boolean);
    expect(userIds.sort()).toEqual(['teamer-1', 'ver-1']);
    expect(guestIds).toEqual(['guest-1']);
    expect(sync.capture).toHaveBeenCalledWith('ChatChannel', 'CREATE', channel.id, expect.anything());
  });

  it('does not duplicate the creator if already listed as a participant', async () => {
    const { service } = makeService({ memberships: [{ kcId: 'kc-1', userId: 'ver-1' }] });
    const channel = await service.createGruppe('kc-1', 'X', 'ver-1', { userIds: ['ver-1'] });
    const userIds = channel.participants.map((p: any) => p.userId).filter(Boolean);
    expect(userIds).toEqual(['ver-1']);
  });

  it('rejects a participant who is not a member of the KC', async () => {
    const { service } = makeService({ memberships: [] });
    await expect(
      service.createGruppe('kc-1', 'X', 'ver-1', { userIds: ['ghost'] }),
    ).rejects.toBeInstanceOf(BadRequestException);
  });

  it('rejects a guest who is not part of the KC', async () => {
    const { service } = makeService({ guests: [{ id: 'guest-1', kcId: 'kc-2' }] });
    await expect(
      service.createGruppe('kc-1', 'X', 'ver-1', { guestIds: ['guest-1'] }),
    ).rejects.toBeInstanceOf(BadRequestException);
  });
});

describe('ChatService participant management', () => {
  function seedGruppe() {
    const channels = {
      'chan-1': { id: 'chan-1', kcId: 'kc-1', type: ChatChannelType.GRUPPE, createdByUserId: 'ver-1', gemeindeId: null },
    };
    return channels;
  }

  it('lets the creator add a team user', async () => {
    const { service } = makeService({
      channels: seedGruppe(),
      memberships: [{ kcId: 'kc-1', userId: 'teamer-1' }],
    });
    const p = await service.addParticipant('chan-1', VERANTW, { userId: 'teamer-1' });
    expect(p.userId).toBe('teamer-1');
  });

  it('lets a Leitungsteam member add a guest even if not the creator', async () => {
    const { service } = makeService({
      channels: seedGruppe(),
      guests: [{ id: 'guest-1', kcId: 'kc-1' }],
    });
    const p = await service.addParticipant('chan-1', LT, { guestId: 'guest-1' });
    expect(p.guestAccountId).toBe('guest-1');
  });

  it('forbids a plain Teamer (not creator, not LT, not Verantwortliche/r) from managing participants', async () => {
    const { service } = makeService({ channels: seedGruppe() });
    await expect(
      service.addParticipant('chan-1', TEAMER, { userId: 'teamer-1' }),
    ).rejects.toBeInstanceOf(ForbiddenException);
  });

  it('forbids guests from managing participants', async () => {
    const { service } = makeService({ channels: seedGruppe() });
    await expect(
      service.addParticipant('chan-1', guestCaller('g-1', 'kc-1') as never, { userId: 'x' }),
    ).rejects.toBeInstanceOf(ForbiddenException);
  });

  it('404s for a non-GRUPPE channel', async () => {
    const channels = {
      'chan-2': { id: 'chan-2', kcId: 'kc-1', type: ChatChannelType.GEMEINDE_GRUPPE, createdByUserId: null },
    };
    const { service } = makeService({ channels });
    await expect(
      service.addParticipant('chan-2', LT, { userId: 'teamer-1' }),
    ).rejects.toBeInstanceOf(NotFoundException);
  });

  it('rejects adding a user not in the KC', async () => {
    const { service } = makeService({ channels: seedGruppe(), memberships: [] });
    await expect(
      service.addParticipant('chan-1', LT, { userId: 'ghost' }),
    ).rejects.toBeInstanceOf(BadRequestException);
  });

  it('removes a participant and is a no-op if already absent', async () => {
    const { service } = makeService({
      channels: seedGruppe(),
      memberships: [{ kcId: 'kc-1', userId: 'teamer-1' }],
    });
    await service.addParticipant('chan-1', VERANTW, { userId: 'teamer-1' });
    const res = await service.removeParticipant('chan-1', VERANTW, { userId: 'teamer-1' });
    expect(res).toEqual({ ok: true });
    const res2 = await service.removeParticipant('chan-1', VERANTW, { userId: 'teamer-1' });
    expect(res2).toEqual({ ok: true });
  });
});

describe('ChatService GRUPPE read/write access', () => {
  function seedGruppeWithParticipants(participants: any[]) {
    return {
      'chan-1': {
        id: 'chan-1',
        kcId: 'kc-1',
        type: ChatChannelType.GRUPPE,
        createdByUserId: 'ver-1',
        gemeindeId: null,
        participants,
      },
    };
  }

  it('lets a listed guest read messages', async () => {
    const { service } = makeService({
      channels: seedGruppeWithParticipants([{ userId: null, guestAccountId: 'guest-1' }]),
    });
    await expect(
      service.assertCanRead('chan-1', guestCaller('guest-1', 'kc-1') as never),
    ).resolves.toBeDefined();
  });

  it('forbids a guest not in the participant list', async () => {
    const { service } = makeService({
      channels: seedGruppeWithParticipants([{ userId: null, guestAccountId: 'guest-1' }]),
    });
    await expect(
      service.assertCanRead('chan-1', guestCaller('guest-2', 'kc-1') as never),
    ).rejects.toBeInstanceOf(ForbiddenException);
  });

  it('forbids a team user not in the participant list', async () => {
    const { service } = makeService({
      channels: seedGruppeWithParticipants([{ userId: 'someone-else', guestAccountId: null }]),
    });
    await expect(service.assertCanRead('chan-1', TEAMER)).rejects.toBeInstanceOf(ForbiddenException);
  });
});