import { vi, describe, it, expect, beforeEach } from 'vitest';
import { useCacheManagement } from '../../hooks/useCacheManagement';

// Mock the MassiveLibraryManager
vi.mock('../../services/MassiveLibraryManager', () => ({
  default: vi.fn().mockImplementation(() => ({
    initialize: vi.fn().mockResolvedValue(undefined),
    getLibraryStatus: vi.fn().mockResolvedValue({
      totalSize: 1024 * 1024 * 100,
      songCount: 250,
      availableSpace: 1024 * 1024 * 1024 * 5,
      deviceType: {
        type: 'mobile',
        model: 'iPhone',
        capabilities: {
          maxStorage: 1024 * 1024 * 1024 * 10,
          compressionSupport: true,
          backgroundProcessing: true
        }
      },
      cacheStrategy: 'balanced',
      compressionRatio: 0.75,
      shards: []
    }),
    cleanup: vi.fn().mockResolvedValue(undefined)
  }))
}));

// Mock IndexedDB
const mockIndexedDB = {
  deleteDatabase: vi.fn().mockImplementation(() => ({
    onsuccess: null,
    onerror: null,
    onblocked: null
  }))
};

Object.defineProperty(global, 'indexedDB', {
  value: mockIndexedDB,
  writable: true
});

// Mock window.confirm
Object.defineProperty(global, 'confirm', {
  value: vi.fn(() => true),
  writable: true
});

describe('useCacheManagement Hook', () => {
  beforeEach(() => {
    vi.clearAllMocks();
  });

  it('should initialize with loading state', () => {
    // This test verifies the hook structure exists
    expect(typeof useCacheManagement).toBe('function');
  });

  it('should format bytes correctly', () => {
    const formatBytes = (bytes: number) => {
      if (bytes === 0) return '0 B';
      const k = 1024;
      const sizes = ['B', 'KB', 'MB', 'GB', 'TB'];
      const i = Math.floor(Math.log(bytes) / Math.log(k));
      return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
    };

    expect(formatBytes(0)).toBe('0 B');
    expect(formatBytes(1024)).toBe('1 KB');
    expect(formatBytes(1024 * 1024)).toBe('1 MB');
    expect(formatBytes(1024 * 1024 * 1024)).toBe('1 GB');
    expect(formatBytes(1536)).toBe('1.5 KB');
  });

  it('should handle cache clearing with confirmation', async () => {
    const mockConfirm = vi.fn(() => true);
    global.confirm = mockConfirm;

    // Simulate cache clearing logic
    const clearCache = async () => {
      if (!confirm('Are you sure you want to clear all cached songs? This will remove all offline music and cannot be undone.')) {
        return;
      }
      
      // Clear IndexedDB
      await new Promise<void>((resolve) => {
        const deleteRequest = indexedDB.deleteDatabase('MassiveMusicLibrary');
        // Simulate success
        setTimeout(() => resolve(), 10);
      });
    };

    await clearCache();
    expect(mockConfirm).toHaveBeenCalledWith('Are you sure you want to clear all cached songs? This will remove all offline music and cannot be undone.');
  });

  it('should handle cache clearing cancellation', async () => {
    const mockConfirm = vi.fn(() => false);
    global.confirm = mockConfirm;

    let cleared = false;
    const clearCache = async () => {
      if (!confirm('Are you sure you want to clear all cached songs? This will remove all offline music and cannot be undone.')) {
        return;
      }
      cleared = true;
    };

    await clearCache();
    expect(mockConfirm).toHaveBeenCalled();
    expect(cleared).toBe(false);
  });

  it('should validate cache status structure', () => {
    const mockStatus = {
      totalSize: 1024 * 1024 * 100,
      songCount: 250,
      availableSpace: 1024 * 1024 * 1024 * 5,
      deviceType: {
        type: 'mobile',
        model: 'iPhone',
        capabilities: {
          maxStorage: 1024 * 1024 * 1024 * 10,
          compressionSupport: true,
          backgroundProcessing: true
        }
      },
      cacheStrategy: 'balanced',
      compressionRatio: 0.75,
      shards: []
    };

    // Validate required properties exist
    expect(mockStatus).toHaveProperty('totalSize');
    expect(mockStatus).toHaveProperty('songCount');
    expect(mockStatus).toHaveProperty('availableSpace');
    expect(mockStatus).toHaveProperty('deviceType');
    expect(mockStatus).toHaveProperty('cacheStrategy');
    expect(mockStatus).toHaveProperty('compressionRatio');
    expect(mockStatus).toHaveProperty('shards');

    // Validate device type structure
    expect(mockStatus.deviceType).toHaveProperty('type');
    expect(mockStatus.deviceType).toHaveProperty('capabilities');
    expect(mockStatus.deviceType.capabilities).toHaveProperty('maxStorage');
  });

  it('should calculate storage percentage correctly', () => {
    const calculateStoragePercentage = (totalSize: number, maxStorage: number) => {
      return maxStorage > 0 ? (totalSize / maxStorage) * 100 : 0;
    };

    expect(calculateStoragePercentage(1024 * 1024 * 1024, 1024 * 1024 * 1024 * 10)).toBe(10); // 1GB / 10GB = 10%
    expect(calculateStoragePercentage(0, 1024 * 1024 * 1024)).toBe(0); // 0 / 1GB = 0%
    expect(calculateStoragePercentage(1024, 0)).toBe(0); // Division by zero protection
  });
});