import { describe, it, expect, vi, beforeEach } from 'vitest';
import { DeleteUserMutation } from './DeleteUserMutation';
import { AdminService } from '@/lib/services/admin/AdminService';
import { Result } from '@/lib/contracts/Result';

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

vi.mock('@/lib/config/apiBaseUrl', () => ({
  getWebsiteApiBaseUrl: () => 'http://localhost:3000',
}));

vi.mock('@/lib/config/env', () => ({
  getWebsiteServerEnv: () => ({ NODE_ENV: 'test' }),
}));

describe('DeleteUserMutation', () => {
  let mutation: DeleteUserMutation;
  let mockServiceInstance: any;

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

  describe('execute', () => {
    describe('happy paths', () => {
      it('should successfully delete a user', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.ok(undefined));

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

        // Assert
        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledTimes(1);
      });

      it('should handle deletion without userId parameter', async () => {
        // Arrange
        const input = { userId: 'user-456' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.ok(undefined));

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

        // Assert
        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledWith();
      });
    });

    describe('failure modes', () => {
      it('should handle service failure during deletion', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        const serviceError = new Error('Service error');
        mockServiceInstance.deleteUser.mockRejectedValue(serviceError);

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

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('deleteFailed');
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning error result', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        const domainError = { type: 'serverError', message: 'Database connection failed' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.err(domainError));

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

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('serverError');
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning userNotFound error', async () => {
        // Arrange
        const input = { userId: 'user-999' };
        const domainError = { type: 'notFound', message: 'User not found' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.err(domainError));

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

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('userNotFound');
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledTimes(1);
      });

      it('should handle service returning noPermission error', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        const domainError = { type: 'unauthorized', message: 'Insufficient permissions' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.err(domainError));

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

        // Assert
        expect(result.isErr()).toBe(true);
        expect(result.getError()).toBe('noPermission');
        expect(mockServiceInstance.deleteUser).toHaveBeenCalledTimes(1);
      });
    });

    describe('error mapping', () => {
      it('should map various domain errors to mutation errors', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        const testCases = [
          { domainError: { type: 'notFound' }, expectedError: 'userNotFound' },
          { domainError: { type: 'unauthorized' }, expectedError: 'noPermission' },
          { domainError: { type: 'validationError' }, expectedError: 'invalidData' },
          { domainError: { type: 'serverError' }, expectedError: 'serverError' },
          { domainError: { type: 'networkError' }, expectedError: 'networkError' },
          { domainError: { type: 'notImplemented' }, expectedError: 'notImplemented' },
          { domainError: { type: 'unknown' }, expectedError: 'unknown' },
        ];

        for (const testCase of testCases) {
          mockServiceInstance.deleteUser.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 userId input', async () => {
        // Arrange
        const input = { userId: 'user-123' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.ok(undefined));

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

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

      it('should handle empty userId gracefully', async () => {
        // Arrange
        const input = { userId: '' };
        mockServiceInstance.deleteUser.mockResolvedValue(Result.ok(undefined));

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

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

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

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