/**
 * Tests for Error Handler Service
 */

import {
  createErrorFromApi,
  createErrorFromException,
  createNetworkError,
  createValidationError,
  createErrorFromUnknown,
  createError,
  calculateRetryDelay,
  ErrorCodes,
} from '@/services/errorHandler';
import { ErrorCategory, ErrorSeverity, isAppError, isRetryableError, isAuthError } from '@/types/errors';

describe('errorHandler', () => {
  describe('createErrorFromApi', () => {
    it('should create error from API error with code', () => {
      const apiError = {
        message: 'Invalid email address',
        code: 'INVALID_EMAIL',
        status: 400,
      };

      const error = createErrorFromApi(apiError);

      expect(error.message).toBe('Invalid email address');
      expect(error.code).toBe('INVALID_EMAIL');
      expect(error.status).toBe(400);
      expect(error.category).toBe('validation');
      expect(error.severity).toBe('error');
      expect(error.errorId).toBeDefined();
      expect(error.timestamp).toBeInstanceOf(Date);
    });

    it('should classify 401 status as authentication error', () => {
      const apiError = {
        message: 'Unauthorized',
        status: 401,
      };

      const error = createErrorFromApi(apiError);

      expect(error.category).toBe('authentication');
      expect(error.retry.isRetryable).toBe(false);
    });

    it('should classify 404 status as notFound error', () => {
      const apiError = {
        message: 'Not found',
        status: 404,
      };

      const error = createErrorFromApi(apiError);

      expect(error.category).toBe('notFound');
      expect(error.retry.isRetryable).toBe(false);
    });

    it('should classify 500 status as server error with retry', () => {
      const apiError = {
        message: 'Internal server error',
        status: 500,
      };

      const error = createErrorFromApi(apiError);

      expect(error.category).toBe('server');
      expect(error.retry.isRetryable).toBe(true);
    });

    it('should classify 429 status as rate limit error', () => {
      const apiError = {
        message: 'Too many requests',
        status: 429,
      };

      const error = createErrorFromApi(apiError);

      expect(error.category).toBe('rateLimit');
      expect(error.retry.isRetryable).toBe(true);
    });

    it('should include context in error', () => {
      const apiError = { message: 'Error', code: 'TEST' };
      const context = { userId: 123, action: 'test' };

      const error = createErrorFromApi(apiError, context);

      expect(error.context).toEqual(context);
    });
  });

  describe('createErrorFromException', () => {
    it('should create error from JavaScript Error', () => {
      const jsError = new Error('Something went wrong');

      const error = createErrorFromException(jsError);

      expect(error.message).toBe('Something went wrong');
      expect(error.code).toBe(ErrorCodes.EXCEPTION);
      expect(error.originalError).toBe(jsError);
    });

    it('should use custom code when provided', () => {
      const jsError = new Error('Network failed');

      const error = createErrorFromException(jsError, ErrorCodes.NETWORK_ERROR);

      expect(error.code).toBe(ErrorCodes.NETWORK_ERROR);
      expect(error.category).toBe('network');
    });
  });

  describe('createNetworkError', () => {
    it('should create network error with default message', () => {
      const error = createNetworkError();

      expect(error.code).toBe(ErrorCodes.NETWORK_ERROR);
      expect(error.category).toBe('network');
      expect(error.severity).toBe('warning');
      expect(error.retry.isRetryable).toBe(true);
    });

    it('should create timeout error when specified', () => {
      const error = createNetworkError('Request timed out', true);

      expect(error.code).toBe(ErrorCodes.NETWORK_TIMEOUT);
      expect(error.category).toBe('timeout');
      expect(error.retry.isRetryable).toBe(true);
    });
  });

  describe('createValidationError', () => {
    it('should create validation error with field errors', () => {
      const fieldErrors = [
        { field: 'email', message: 'Invalid email' },
        { field: 'phone', message: 'Invalid phone' },
      ];

      const error = createValidationError('Validation failed', fieldErrors);

      expect(error.code).toBe(ErrorCodes.VALIDATION_ERROR);
      expect(error.category).toBe('validation');
      expect(error.fieldErrors).toEqual(fieldErrors);
      expect(error.retry.isRetryable).toBe(false);
    });
  });

  describe('createErrorFromUnknown', () => {
    it('should handle string errors', () => {
      const error = createErrorFromUnknown('Something bad');

      expect(error.message).toBe('Something bad');
    });

    it('should handle Error objects', () => {
      const jsError = new Error('Test error');
      const error = createErrorFromUnknown(jsError);

      expect(error.message).toBe('Test error');
      expect(error.originalError).toBe(jsError);
    });

    it('should handle API-like objects', () => {
      const apiLike = { message: 'API error', code: 'TEST_CODE' };
      const error = createErrorFromUnknown(apiLike);

      expect(error.message).toBe('API error');
      expect(error.code).toBe('TEST_CODE');
    });

    it('should handle null/undefined', () => {
      const error = createErrorFromUnknown(null);

      expect(error.message).toBe('An unknown error occurred');
      expect(error.code).toBe(ErrorCodes.UNKNOWN_ERROR);
    });

    it('should pass through AppError objects', () => {
      const original = createError(ErrorCodes.NETWORK_ERROR);
      const result = createErrorFromUnknown(original);

      expect(result.errorId).toBe(original.errorId);
    });
  });

  describe('createError', () => {
    it('should create error with predefined code', () => {
      const error = createError(ErrorCodes.SUBSCRIPTION_REQUIRED);

      expect(error.code).toBe(ErrorCodes.SUBSCRIPTION_REQUIRED);
      expect(error.category).toBe('subscription');
      expect(error.userMessage).toBeDefined();
    });

    it('should use custom message when provided', () => {
      const error = createError(ErrorCodes.NOT_FOUND, 'User not found');

      expect(error.message).toBe('User not found');
    });
  });

  describe('calculateRetryDelay', () => {
    it('should return base delay without exponential backoff', () => {
      const policy = {
        isRetryable: true,
        retryDelayMs: 1000,
        useExponentialBackoff: false,
      };

      expect(calculateRetryDelay(policy, 0)).toBe(1000);
      expect(calculateRetryDelay(policy, 1)).toBe(1000);
      expect(calculateRetryDelay(policy, 2)).toBe(1000);
    });

    it('should increase delay with exponential backoff', () => {
      const policy = {
        isRetryable: true,
        retryDelayMs: 1000,
        useExponentialBackoff: true,
      };

      const delay0 = calculateRetryDelay(policy, 0);
      const delay1 = calculateRetryDelay(policy, 1);
      const delay2 = calculateRetryDelay(policy, 2);

      // With jitter, delays should be approximately 1000, 2000, 4000
      expect(delay0).toBeGreaterThanOrEqual(1000);
      expect(delay0).toBeLessThan(1300); // 1000 + 30% jitter
      expect(delay1).toBeGreaterThanOrEqual(2000);
      expect(delay1).toBeLessThan(2600);
      expect(delay2).toBeGreaterThanOrEqual(4000);
      expect(delay2).toBeLessThan(5200);
    });

    it('should cap delay at 30 seconds', () => {
      const policy = {
        isRetryable: true,
        retryDelayMs: 10000,
        useExponentialBackoff: true,
      };

      const delay = calculateRetryDelay(policy, 5); // Would be 320000ms without cap

      expect(delay).toBeLessThanOrEqual(30000);
    });

    it('should return 1000ms when no delay specified', () => {
      const policy = { isRetryable: true };

      expect(calculateRetryDelay(policy, 0)).toBe(1000);
    });
  });

  describe('type guards', () => {
    describe('isAppError', () => {
      it('should return true for valid AppError', () => {
        const error = createError(ErrorCodes.NETWORK_ERROR);
        expect(isAppError(error)).toBe(true);
      });

      it('should return false for plain objects', () => {
        expect(isAppError({ message: 'test' })).toBe(false);
      });

      it('should return false for null/undefined', () => {
        expect(isAppError(null)).toBe(false);
        expect(isAppError(undefined)).toBe(false);
      });
    });

    describe('isRetryableError', () => {
      it('should return true for network errors', () => {
        const error = createNetworkError();
        expect(isRetryableError(error)).toBe(true);
      });

      it('should return false for auth errors', () => {
        const error = createError(ErrorCodes.UNAUTHORIZED);
        expect(isRetryableError(error)).toBe(false);
      });

      it('should return false for validation errors', () => {
        const error = createValidationError('Invalid input');
        expect(isRetryableError(error)).toBe(false);
      });
    });

    describe('isAuthError', () => {
      it('should return true for unauthorized errors', () => {
        const error = createError(ErrorCodes.UNAUTHORIZED);
        expect(isAuthError(error)).toBe(true);
      });

      it('should return true for token expired errors', () => {
        const error = createError(ErrorCodes.TOKEN_EXPIRED);
        expect(isAuthError(error)).toBe(true);
      });

      it('should return false for other errors', () => {
        const error = createNetworkError();
        expect(isAuthError(error)).toBe(false);
      });
    });
  });

  describe('error code classification', () => {
    const testCases: [string, ErrorCategory][] = [
      [ErrorCodes.NETWORK_ERROR, 'network'],
      [ErrorCodes.NETWORK_TIMEOUT, 'timeout'],
      [ErrorCodes.UNAUTHORIZED, 'authentication'],
      [ErrorCodes.TOKEN_EXPIRED, 'authentication'],
      [ErrorCodes.FORBIDDEN, 'permission'],
      [ErrorCodes.NOT_FOUND, 'notFound'],
      [ErrorCodes.BENEFICIARY_NOT_FOUND, 'notFound'],
      [ErrorCodes.CONFLICT, 'conflict'],
      [ErrorCodes.DUPLICATE_ENTRY, 'conflict'],
      [ErrorCodes.VALIDATION_ERROR, 'validation'],
      [ErrorCodes.INVALID_EMAIL, 'validation'],
      [ErrorCodes.RATE_LIMITED, 'rateLimit'],
      [ErrorCodes.SERVER_ERROR, 'server'],
      [ErrorCodes.BLE_NOT_AVAILABLE, 'ble'],
      [ErrorCodes.SENSOR_OFFLINE, 'sensor'],
      [ErrorCodes.SUBSCRIPTION_REQUIRED, 'subscription'],
    ];

    it.each(testCases)('should classify %s as %s category', (code, expectedCategory) => {
      const error = createError(code as any);
      expect(error.category).toBe(expectedCategory);
    });
  });

  describe('user messages', () => {
    it('should provide user-friendly message for network error', () => {
      const error = createError(ErrorCodes.NETWORK_ERROR);
      expect(error.userMessage).toContain('internet');
    });

    it('should provide user-friendly message for auth error', () => {
      const error = createError(ErrorCodes.UNAUTHORIZED);
      expect(error.userMessage).toContain('session');
    });

    it('should provide user-friendly message for subscription error', () => {
      const error = createError(ErrorCodes.SUBSCRIPTION_REQUIRED);
      expect(error.userMessage).toContain('subscription');
    });
  });

  describe('action hints', () => {
    it('should provide action hint for network error', () => {
      const error = createError(ErrorCodes.NETWORK_ERROR);
      expect(error.actionHint).toBeDefined();
      expect(error.actionHint).toContain('connection');
    });

    it('should provide action hint for auth error', () => {
      const error = createError(ErrorCodes.UNAUTHORIZED);
      expect(error.actionHint).toBeDefined();
      expect(error.actionHint).toContain('log in');
    });

    it('should provide action hint for BLE error', () => {
      const error = createError(ErrorCodes.BLE_NOT_ENABLED);
      expect(error.actionHint).toBeDefined();
      expect(error.actionHint).toContain('Bluetooth');
    });
  });
});