/**
 * Offline Store Tests
 *
 * Tests for offline state management, message queuing,
 * reconnection logic, and graceful degradation.
 */

import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import { useOfflineStore, type QueuedMessage } from '../../src/store/offlineStore';
import { localStorageMock } from '../setup';

// ── Mock dependencies (vi.hoisted for availability in hoisted vi.mock) ──

const { mockGetConnectionState, mockGetClient, mockConnect, mockGenerateRandomString, resetIdCounter } = vi.hoisted(() => {
  let counter = 0;
  return {
    mockGetConnectionState: vi.fn(() => 'disconnected'),
    mockGetClient: vi.fn(() => ({ chat: vi.fn(async () => {}) })),
    mockConnect: vi.fn(async () => {}),
    mockGenerateRandomString: (len: number) => String(++counter).padStart(len, '0'),
    resetIdCounter: () => { counter = 0; },
  };
});

vi.mock('../../src/store/connectionStore', () => ({
  useConnectionStore: {
    getState: () => ({
      connect: mockConnect,
      connectionState: 'connected',
    }),
    subscribe: () => () => {},
  },
  getConnectionState: () => mockGetConnectionState(),
  getClient: () => mockGetClient(),
}));

vi.mock('../../src/lib/crypto-utils', () => ({
  generateRandomString: mockGenerateRandomString,
}));

vi.mock('../../src/lib/logger', () => ({
  createLogger: () => ({
    info: vi.fn(),
    warn: vi.fn(),
    error: vi.fn(),
    debug: vi.fn(),
  }),
}));

beforeEach(() => {
  vi.clearAllMocks();
  resetIdCounter();
  vi.useFakeTimers({ shouldAdvanceTime: true });
  localStorageMock.clear();

  // Reset store to initial state
  useOfflineStore.setState({
    isOffline: false,
    isReconnecting: false,
    reconnectAttempt: 0,
    nextReconnectDelay: 1000,
    lastOnlineTime: null,
    queuedMessages: [],
    maxRetryCount: 5,
    maxQueueSize: 100,
  });

  // Default: disconnected so retryAllMessages won't try to send
  mockGetConnectionState.mockReturnValue('disconnected');
});

afterEach(() => {
  vi.useRealTimers();
});

// ═══════════════════════════════════════════════════════════════════
// Initial State
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — initial state', () => {
  it('should start online', () => {
    expect(useOfflineStore.getState().isOffline).toBe(false);
  });

  it('should have empty queue', () => {
    expect(useOfflineStore.getState().queuedMessages).toEqual([]);
  });

  it('should have no reconnect attempt', () => {
    expect(useOfflineStore.getState().reconnectAttempt).toBe(0);
  });

  it('should have default max values', () => {
    const state = useOfflineStore.getState();
    expect(state.maxRetryCount).toBe(5);
    expect(state.maxQueueSize).toBe(100);
  });
});

// ═══════════════════════════════════════════════════════════════════
// setOffline
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — setOffline', () => {
  it('should set offline state', () => {
    useOfflineStore.getState().setOffline(true);

    expect(useOfflineStore.getState().isOffline).toBe(true);
  });

  it('should record lastOnlineTime when going online', () => {
    useOfflineStore.getState().setOffline(true);
    useOfflineStore.getState().setOffline(false);

    expect(useOfflineStore.getState().lastOnlineTime).toBeGreaterThan(0);
  });

  it('should schedule reconnect when going offline', () => {
    useOfflineStore.getState().setOffline(true);

    expect(useOfflineStore.getState().isReconnecting).toBe(true);
    expect(useOfflineStore.getState().reconnectAttempt).toBe(1);
  });

  it('should cancel reconnect and reset delay when going online', () => {
    useOfflineStore.getState().setOffline(true);
    useOfflineStore.getState().setOffline(false);

    const state = useOfflineStore.getState();
    expect(state.reconnectAttempt).toBe(0);
    expect(state.nextReconnectDelay).toBe(1000);
  });
});

// ═══════════════════════════════════════════════════════════════════
// queueMessage
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — queueMessage', () => {
  it('should add message to queue', () => {
    const id = useOfflineStore.getState().queueMessage('Hello', 'agent-1', 'session-1');

    expect(id).toBeTruthy();
    const queue = useOfflineStore.getState().queuedMessages;
    expect(queue).toHaveLength(1);
    expect(queue[0].content).toBe('Hello');
    expect(queue[0].agentId).toBe('agent-1');
    expect(queue[0].sessionKey).toBe('session-1');
    expect(queue[0].status).toBe('pending');
    expect(queue[0].retryCount).toBe(0);
  });

  it('should generate unique IDs', () => {
    const id1 = useOfflineStore.getState().queueMessage('msg1');
    const id2 = useOfflineStore.getState().queueMessage('msg2');

    expect(id1).not.toBe(id2);
  });

  it('should enforce max queue size', () => {
    const state = useOfflineStore.getState();
    const maxSize = state.maxQueueSize;

    for (let i = 0; i < maxSize + 5; i++) {
      state.queueMessage(`Message ${i}`);
    }

    expect(useOfflineStore.getState().queuedMessages.length).toBeLessThanOrEqual(maxSize + 1);
  });
});

// ═══════════════════════════════════════════════════════════════════
// updateMessageStatus
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — updateMessageStatus', () => {
  it('should update message status', () => {
    const id = useOfflineStore.getState().queueMessage('Test');

    useOfflineStore.getState().updateMessageStatus(id, 'sending');

    const msg = useOfflineStore.getState().queuedMessages.find(m => m.id === id);
    expect(msg!.status).toBe('sending');
  });

  it('should increment retryCount on failed status', () => {
    const id = useOfflineStore.getState().queueMessage('Test');

    useOfflineStore.getState().updateMessageStatus(id, 'failed', 'Network error');

    const msg = useOfflineStore.getState().queuedMessages.find(m => m.id === id);
    expect(msg!.retryCount).toBe(1);
    expect(msg!.lastError).toBe('Network error');
  });

  it('should not affect other messages', () => {
    const id1 = useOfflineStore.getState().queueMessage('Msg 1');
    const id2 = useOfflineStore.getState().queueMessage('Msg 2');

    useOfflineStore.getState().updateMessageStatus(id1, 'sent');

    const msg2 = useOfflineStore.getState().queuedMessages.find(m => m.id === id2);
    expect(msg2!.status).toBe('pending');
  });
});

// ═══════════════════════════════════════════════════════════════════
// removeMessage
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — removeMessage', () => {
  it('should remove message by id', () => {
    const id1 = useOfflineStore.getState().queueMessage('Msg 1');
    const id2 = useOfflineStore.getState().queueMessage('Msg 2');

    useOfflineStore.getState().removeMessage(id1);

    const queue = useOfflineStore.getState().queuedMessages;
    expect(queue).toHaveLength(1);
    expect(queue[0].id).toBe(id2);
  });
});

// ═══════════════════════════════════════════════════════════════════
// clearQueue
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — clearQueue', () => {
  it('should remove all messages', () => {
    useOfflineStore.getState().queueMessage('Msg 1');
    useOfflineStore.getState().queueMessage('Msg 2');

    useOfflineStore.getState().clearQueue();

    expect(useOfflineStore.getState().queuedMessages).toEqual([]);
  });
});

// ═══════════════════════════════════════════════════════════════════
// getPendingMessages / hasPendingMessages
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — getters', () => {
  it('getPendingMessages should return pending and failed', () => {
    const id1 = useOfflineStore.getState().queueMessage('Pending');
    const id2 = useOfflineStore.getState().queueMessage('Will fail');
    const id3 = useOfflineStore.getState().queueMessage('Will send');

    useOfflineStore.getState().updateMessageStatus(id2, 'failed', 'Error');
    useOfflineStore.getState().updateMessageStatus(id3, 'sent');

    const pending = useOfflineStore.getState().getPendingMessages();
    expect(pending).toHaveLength(2);
    expect(pending.map(m => m.id)).toContain(id1);
    expect(pending.map(m => m.id)).toContain(id2);
  });

  it('hasPendingMessages should return true when pending exist', () => {
    expect(useOfflineStore.getState().hasPendingMessages()).toBe(false);

    useOfflineStore.getState().queueMessage('Test');

    expect(useOfflineStore.getState().hasPendingMessages()).toBe(true);
  });

  it('hasPendingMessages should return false when all sent', () => {
    const id = useOfflineStore.getState().queueMessage('Test');
    useOfflineStore.getState().updateMessageStatus(id, 'sent');

    expect(useOfflineStore.getState().hasPendingMessages()).toBe(false);
  });
});

// ═══════════════════════════════════════════════════════════════════
// reconnect schedule
// ═══════════════════════════════════════════════════════════════════

describe('offlineStore — reconnection', () => {
  it('should increase delay with backoff', () => {
    useOfflineStore.getState().setOffline(true);

    const delay1 = useOfflineStore.getState().nextReconnectDelay;

    // Simulate failed reconnect cycle
    useOfflineStore.getState().setReconnecting(false);
    useOfflineStore.getState().scheduleReconnect();

    const delay2 = useOfflineStore.getState().nextReconnectDelay;
    expect(delay2).toBeGreaterThan(delay1);
  });

  it('should cap delay at maximum', () => {
    useOfflineStore.setState({ nextReconnectDelay: 50000 });

    useOfflineStore.getState().setOffline(true);
    useOfflineStore.getState().setReconnecting(false);
    useOfflineStore.getState().scheduleReconnect();

    expect(useOfflineStore.getState().nextReconnectDelay).toBeLessThanOrEqual(60000);
  });

  it('should cancel reconnect', () => {
    useOfflineStore.getState().setOffline(true);
    expect(useOfflineStore.getState().isReconnecting).toBe(true);

    useOfflineStore.getState().cancelReconnect();
    expect(useOfflineStore.getState().isReconnecting).toBe(false);
  });

  it('should not schedule reconnect when online', () => {
    useOfflineStore.getState().scheduleReconnect();
    expect(useOfflineStore.getState().reconnectAttempt).toBe(0);
  });
});