import { describe, it, expect, vi, beforeEach } from 'vitest';
import { ResetPasswordMutation } from './ResetPasswordMutation';
import { AuthService } from '@/lib/services/auth/AuthService';
import { Result } from '@/lib/contracts/Result';

// Mock dependencies
vi.mock('@/lib/services/auth/AuthService', () => {
  return {
    AuthService: vi.fn(),
  };
});

describe('ResetPasswordMutation', () => {
  let mutation: ResetPasswordMutation;
  let mockServiceInstance: { resetPassword: ReturnType<typeof vi.fn> };

  beforeEach(() => {
    vi.clearAllMocks();
    mutation = new ResetPasswordMutation();
    mockServiceInstance = {
      resetPassword: vi.fn(),
    };
    // Use mockImplementation to return the instance
    (AuthService as any).mockImplementation(function() {
      return mockServiceInstance;
    });
  });

  describe('execute', () => {
    describe('happy paths', () => {
      it('should successfully reset password with valid token', async () => {
        // Arrange
        const input = { token: 'valid-token-123', newPassword: 'newSecurePassword123' };
        const serviceOutput = { message: 'Password reset successfully' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.ok(serviceOutput));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toEqual(serviceOutput);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledWith(input);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle reset password with complex password', async () => {
        // Arrange
        const input = { token: 'valid-token-456', newPassword: 'ComplexP@ssw0rd!2024' };
        const serviceOutput = { message: 'Password reset successfully' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.ok(serviceOutput));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toEqual(serviceOutput);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledWith(input);
      });
    });

    describe('failure modes', () => {
      it('should handle service failure during password reset', async () => {
        // Arrange
        const input = { token: 'expired-token', newPassword: 'newPassword123' };
        const serviceError = new Error('Token expired');
        mockServiceInstance.resetPassword.mockRejectedValue(serviceError);

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('Token expired');
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning error result', async () => {
        // Arrange
        const input = { token: 'invalid-token', newPassword: 'newPassword123' };
        const domainError = { type: 'validationError', message: 'Invalid token' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.err(domainError));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('Invalid token');
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning tokenExpired error', async () => {
        // Arrange
        const input = { token: 'expired-token', newPassword: 'newPassword123' };
        const domainError = { type: 'validationError', message: 'Reset token has expired' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.err(domainError));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('Reset token has expired');
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning weakPassword error', async () => {
        // Arrange
        const input = { token: 'valid-token', newPassword: 'weak' };
        const domainError = { type: 'validationError', message: 'Password does not meet requirements' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.err(domainError));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('Password does not meet requirements');
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning serverError', async () => {
        // Arrange
        const input = { token: 'valid-token', newPassword: 'newPassword123' };
        const domainError = { type: 'serverError', message: 'Database connection failed' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.err(domainError));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('Database connection failed');
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });
    });

    describe('error mapping', () => {
      it('should map various domain errors to mutation errors', async () => {
        // Arrange
        const input = { token: 'valid-token', newPassword: 'newPassword123' };
        const testCases = [
          { domainError: { type: 'validationError', message: 'Invalid token' }, expectedError: 'Invalid token' },
          { domainError: { type: 'serverError', message: 'Server error' }, expectedError: 'Server error' },
          { domainError: { type: 'notFound', message: 'User not found' }, expectedError: 'User not found' },
          { domainError: { type: 'unauthorized', message: 'Unauthorized' }, expectedError: 'Unauthorized' },
        ];

        for (const testCase of testCases) {
          mockServiceInstance.resetPassword.mockResolvedValue(Result.err(testCase.domainError));

          const result = await mutation.execute(input);

          expect(result.isErr()).toBe(true);
          expect(result.getError()).toBe(testCase.expectedError);
        }
      });
    });

    describe('input validation', () => {
      it('should accept valid token and password input', async () => {
        // Arrange
        const input = { token: 'valid-token-123', newPassword: 'newSecurePassword123' };
        mockServiceInstance.resetPassword.mockResolvedValue(
          Result.ok({ message: 'Password reset successfully' })
        );

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledTimes(1);
      });

      it('should handle empty token gracefully', async () => {
        // Arrange
        const input = { token: '', newPassword: 'newPassword123' };
        mockServiceInstance.resetPassword.mockResolvedValue(
          Result.ok({ message: 'Password reset successfully' })
        );

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledWith(input);
      });

      it('should handle empty password gracefully', async () => {
        // Arrange
        const input = { token: 'valid-token', newPassword: '' };
        mockServiceInstance.resetPassword.mockResolvedValue(
          Result.ok({ message: 'Password reset successfully' })
        );

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        expect(mockServiceInstance.resetPassword).toHaveBeenCalledWith(input);
      });
    });

    describe('service instantiation', () => {
      it('should create AuthService instance', () => {
        // Arrange & Act
        const mutation = new ResetPasswordMutation();

        // Assert
        expect(mutation).toBeInstanceOf(ResetPasswordMutation);
      });
    });

    describe('result shape', () => {
      it('should return message on success', async () => {
        // Arrange
        const input = { token: 'valid-token', newPassword: 'newPassword123' };
        const serviceOutput = { message: 'Password reset successfully' };
        mockServiceInstance.resetPassword.mockResolvedValue(Result.ok(serviceOutput));

        // Act
        const result = await mutation.execute(input);

        // Assert
        expect(result.isOk()).toBe(true);
        const resultData = result.unwrap();
        expect(resultData).toEqual(serviceOutput);
        expect(resultData.message).toBe('Password reset successfully');
      });
    });
  });
});