/**
 * Session Persistence Tests - Phase 4.3
 *
 * Tests for automatic session data persistence:
 * - Session lifecycle (start/add/end)
 * - Auto-save functionality
 * - Memory extraction
 * - Session compaction
 * - Crash recovery
 */

import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
import {
  SessionPersistenceService,
  getSessionPersistence,
  resetSessionPersistence,
  startSession,
  addSessionMessage,
  endCurrentSession,
  getCurrentSession,
  DEFAULT_SESSION_CONFIG,
  type SessionState,
  type PersistenceResult,
} from '../../desktop/src/lib/session-persistence';

// === Mock Dependencies ===

const mockVikingClient = {
  isAvailable: vi.fn(async () => true),
  addResource: vi.fn(async () => ({ uri: 'test-uri', status: 'ok' })),
  removeResource: vi.fn(async () => undefined),
  compactSession: vi.fn(async () => '[会话摘要]\n讨论主题: 代码优化\n关键决策: 使用缓存策略'),
  extractMemories: vi.fn(async () => ({
    memories: [
      { content: '用户偏好简洁的回答', type: 'preference', importance: 7 },
    ],
    summary: 'Extracted 1 memory',
    tokensSaved: 100,
  })),
};

vi.mock('../../desktop/src/lib/viking-client', () => ({
  getVikingClient: vi.fn(() => mockVikingClient),
  resetVikingClient: vi.fn(),
  VikingHttpClient: vi.fn(),
}));

const mockMemoryExtractor = {
  extractFromConversation: vi.fn(async () => ({
    items: [{ content: 'Test memory', type: 'fact', importance: 5, tags: [] }],
    saved: 1,
    skipped: 0,
    userProfileUpdated: false,
  })),
};

vi.mock('../../desktop/src/lib/memory-extractor', () => ({
  getMemoryExtractor: vi.fn(() => mockMemoryExtractor),
  resetMemoryExtractor: vi.fn(),
}));

const mockAutonomyManager = {
  evaluate: vi.fn(() => ({
    action: 'memory_save',
    allowed: true,
    requiresApproval: false,
    reason: 'Auto-approved',
    riskLevel: 'low',
    importance: 5,
    timestamp: new Date().toISOString(),
  })),
};

vi.mock('../../desktop/src/lib/autonomy-manager', () => ({
  canAutoExecute: vi.fn(() => ({ canProceed: true, decision: mockAutonomyManager.evaluate() })),
  executeWithAutonomy: vi.fn(async (_action: string, _importance: number, executor: () => unknown) => {
    const result = await executor();
    return { executed: true, result };
  }),
  getAutonomyManager: vi.fn(() => mockAutonomyManager),
}));

// === Session Persistence Tests ===

describe('SessionPersistenceService', () => {
  let service: SessionPersistenceService;

  beforeEach(() => {
    vi.clearAllMocks();
    localStorage.clear();
    resetSessionPersistence();
    service = new SessionPersistenceService();
  });

  afterEach(() => {
    service.stopAutoSave();
    resetSessionPersistence();
  });

  describe('Initialization', () => {
    it('should initialize with default config', () => {
      const config = service.getConfig();
      expect(config.enabled).toBe(true);
      expect(config.autoSaveIntervalMs).toBe(60000);
      expect(config.maxMessagesBeforeCompact).toBe(100);
      expect(config.extractMemoriesOnEnd).toBe(true);
    });

    it('should accept custom config', () => {
      const customService = new SessionPersistenceService({
        autoSaveIntervalMs: 30000,
        maxMessagesBeforeCompact: 50,
      });
      const config = customService.getConfig();
      expect(config.autoSaveIntervalMs).toBe(30000);
      expect(config.maxMessagesBeforeCompact).toBe(50);
    });

    it('should update config', () => {
      service.updateConfig({ autoSaveIntervalMs: 120000 });
      const config = service.getConfig();
      expect(config.autoSaveIntervalMs).toBe(120000);
    });
  });

  describe('Session Lifecycle', () => {
    it('should start a new session', () => {
      const session = service.startSession('agent1', { model: 'gpt-4' });

      expect(session.id).toBeDefined();
      expect(session.agentId).toBe('agent1');
      expect(session.status).toBe('active');
      expect(session.messageCount).toBe(0);
      expect(session.metadata.model).toBe('gpt-4');
    });

    it('should end previous session when starting new one', () => {
      service.startSession('agent1');
      const session2 = service.startSession('agent2');

      expect(session2.agentId).toBe('agent2');
    });

    it('should add messages to session', () => {
      service.startSession('agent1');

      const msg1 = service.addMessage({ role: 'user', content: 'Hello' });
      const msg2 = service.addMessage({ role: 'assistant', content: 'Hi there!' });

      expect(msg1).not.toBeNull();
      expect(msg2).not.toBeNull();
      expect(msg1?.role).toBe('user');
      expect(msg2?.role).toBe('assistant');

      const current = service.getCurrentSession();
      expect(current?.messageCount).toBe(2);
    });

    it('should return null when adding message without session', () => {
      const msg = service.addMessage({ role: 'user', content: 'Hello' });
      expect(msg).toBeNull();
    });

    it('should end session and return result', async () => {
      service.startSession('agent1');
      service.addMessage({ role: 'user', content: 'Hello' });
      service.addMessage({ role: 'assistant', content: 'Hi!' });

      const result = await service.endSession();

      expect(result.saved).toBe(true);
      expect(result.messageCount).toBe(2);
      expect(service.getCurrentSession()).toBeNull();
    });

    it('should return empty result when no session', async () => {
      const result = await service.endSession();

      expect(result.saved).toBe(false);
      expect(result.error).toBe('No active session');
    });
  });

  describe('Session Compaction', () => {
    it('should trigger compaction when threshold reached', async () => {
      const customService = new SessionPersistenceService({
        maxMessagesBeforeCompact: 5,
      });

      customService.startSession('agent1');

      // Add more messages than threshold
      for (let i = 0; i < 7; i++) {
        customService.addMessage({ role: 'user', content: `Message ${i}` });
        customService.addMessage({ role: 'assistant', content: `Response ${i}` });
      }

      // Wait for async compaction to complete
      await new Promise(resolve => setTimeout(resolve, 100));

      // Compaction should have been triggered
      // Since compaction is async and creates a summary, we verify it was attempted
      const session = customService.getCurrentSession();
      // Compaction may or may not complete in time, but session should still be valid
      expect(session).not.toBeNull();
      expect(session!.messages.length).toBeGreaterThan(0);

      customService.stopAutoSave();
    });
  });

  describe('Memory Extraction', () => {
    it('should extract memories on session end', async () => {
      service.startSession('agent1');

      // Add enough messages for extraction
      for (let i = 0; i < 5; i++) {
        service.addMessage({ role: 'user', content: `User message ${i}` });
        service.addMessage({ role: 'assistant', content: `Assistant response ${i}` });
      }

      const result = await service.endSession();

      expect(result.extractedMemories).toBeGreaterThanOrEqual(0);
    });

    it('should skip extraction for short sessions', async () => {
      service.startSession('agent1');
      service.addMessage({ role: 'user', content: 'Hi' });

      const result = await service.endSession();

      // Should not extract memories for sessions with < 4 messages
      expect(mockMemoryExtractor.extractFromConversation).not.toHaveBeenCalled();
    });
  });

  describe('Session History', () => {
    it('should track session history', async () => {
      service.startSession('agent1');
      service.addMessage({ role: 'user', content: 'Hello' });
      await service.endSession();

      const history = service.getSessionHistory();
      expect(history.length).toBe(1);
      expect(history[0].agentId).toBe('agent1');
    });

    it('should limit history size', async () => {
      const customService = new SessionPersistenceService({
        maxSessionHistory: 3,
      });

      // Create 5 sessions
      for (let i = 0; i < 5; i++) {
        customService.startSession(`agent${i}`);
        customService.addMessage({ role: 'user', content: 'Test' });
        await customService.endSession();
      }

      const history = customService.getSessionHistory();
      expect(history.length).toBe(3);
    });

    it('should delete session from history', async () => {
      service.startSession('agent1');
      service.addMessage({ role: 'user', content: 'Test' });
      const result = await service.endSession();

      const deleted = service.deleteSession(result.sessionId);
      expect(deleted).toBe(true);

      const history = service.getSessionHistory();
      expect(history.length).toBe(0);
    });
  });

  describe('Crash Recovery', () => {
    it('should recover from crash', () => {
      // Start a session
      const session = service.startSession('agent1');
      service.addMessage({ role: 'user', content: 'Before crash' });

      // Simulate crash by not ending session
      const savedSession = service.getCurrentSession();
      expect(savedSession).not.toBeNull();

      // Reset service (simulates restart)
      resetSessionPersistence();
      service = new SessionPersistenceService();

      // Recover
      const recovered = service.recoverFromCrash();

      expect(recovered).not.toBeNull();
      expect(recovered?.agentId).toBe('agent1');
      expect(recovered?.status).toBe('active');
    });

    it('should not recover timed-out sessions', async () => {
      const customService = new SessionPersistenceService({
        sessionTimeoutMs: 1000, // 1 second
      });

      customService.startSession('agent1');
      customService.addMessage({ role: 'user', content: 'Test' });

      // Manually set lastActivityAt to past and save to localStorage
      const session = customService.getCurrentSession();
      if (session) {
        session.lastActivityAt = new Date(Date.now() - 5000).toISOString();
        // Force save to localStorage so recovery can find it
        localStorage.setItem('zclaw-current-session', JSON.stringify(session));
      }

      // Stop auto-save to prevent overwriting
      customService.stopAutoSave();

      // Reset and try to recover
      resetSessionPersistence();
      const newService = new SessionPersistenceService({ sessionTimeoutMs: 1000 });
      const recovered = newService.recoverFromCrash();

      expect(recovered).toBeNull();
    });
  });

  describe('Availability', () => {
    it('should check availability', async () => {
      const available = await service.isAvailable();
      expect(available).toBe(true);
    });

    it('should return false when disabled', async () => {
      service.updateConfig({ enabled: false });
      const available = await service.isAvailable();
      expect(available).toBe(false);
    });
  });
});

// === Helper Function Tests ===

describe('Helper Functions', () => {
  beforeEach(() => {
    vi.clearAllMocks();
    localStorage.clear();
    resetSessionPersistence();
  });

  afterEach(() => {
    resetSessionPersistence();
  });

  it('should start session via helper', () => {
    const session = startSession('agent1');
    expect(session.agentId).toBe('agent1');
  });

  it('should add message via helper', () => {
    startSession('agent1');
    const msg = addSessionMessage({ role: 'user', content: 'Test' });
    expect(msg?.content).toBe('Test');
  });

  it('should end session via helper', async () => {
    startSession('agent1');
    addSessionMessage({ role: 'user', content: 'Test' });

    const result = await endCurrentSession();
    expect(result.saved).toBe(true);
  });

  it('should get current session via helper', () => {
    startSession('agent1');
    const session = getCurrentSession();
    expect(session?.agentId).toBe('agent1');
  });
});

// === Integration Tests ===

describe('Session Persistence Integration', () => {
  beforeEach(() => {
    vi.clearAllMocks();
    localStorage.clear();
    resetSessionPersistence();
  });

  afterEach(() => {
    resetSessionPersistence();
  });

  it('should handle Viking client errors gracefully', async () => {
    mockVikingClient.addResource.mockRejectedValueOnce(new Error('Viking error'));

    const service = new SessionPersistenceService({ fallbackToLocal: true });
    service.startSession('agent1');
    service.addMessage({ role: 'user', content: 'Test' });

    const result = await service.endSession();

    // Should still save to local storage
    expect(result.saved).toBe(true);
  });

  it('should handle memory extractor errors gracefully', async () => {
    mockMemoryExtractor.extractFromConversation.mockRejectedValueOnce(new Error('Extraction failed'));

    const service = new SessionPersistenceService();
    service.startSession('agent1');

    for (let i = 0; i < 5; i++) {
      service.addMessage({ role: 'user', content: `Message ${i}` });
      service.addMessage({ role: 'assistant', content: `Response ${i}` });
    }

    const result = await service.endSession();

    // Should still complete session even if extraction fails
    expect(result.saved).toBe(true);
    expect(result.extractedMemories).toBe(0);
  });
});