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

// Mock dependencies
vi.mock('@/lib/config/apiBaseUrl', () => ({
  getWebsiteApiBaseUrl: () => 'http://localhost:3000',
}));
vi.mock('@/lib/config/env', () => ({
  getWebsiteServerEnv: () => ({ NODE_ENV: 'test' }),
}));

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

  beforeEach(() => {
    // Create service instance
    service = new AdminService();
  });

  describe('getDashboardStats', () => {
    describe('happy paths', () => {
      it('should return dashboard statistics successfully', async () => {
        const result = await service.getDashboardStats();

        expect(result.isOk()).toBe(true);
        const stats = result.unwrap();

        // Verify the mock data structure
        expect(stats.totalUsers).toBe(1250);
        expect(stats.activeUsers).toBe(1100);
        expect(stats.suspendedUsers).toBe(50);
        expect(stats.deletedUsers).toBe(100);
        expect(stats.systemAdmins).toBe(5);
        expect(stats.recentLogins).toBe(450);
        expect(stats.newUsersToday).toBe(12);
        expect(stats.userGrowth).toHaveLength(2);
        expect(stats.roleDistribution).toHaveLength(2);
        expect(stats.statusDistribution).toBeDefined();
        expect(stats.activityTimeline).toHaveLength(2);
      });
    });

    describe('aggregation logic', () => {
      it('should aggregate user statistics correctly', async () => {
        const result = await service.getDashboardStats();

        expect(result.isOk()).toBe(true);
        const stats = result.unwrap();

        // Verify aggregation logic
        expect(stats.totalUsers).toBe(1250);
        expect(stats.activeUsers).toBe(1100);
        expect(stats.suspendedUsers).toBe(50);
        expect(stats.deletedUsers).toBe(100);
        expect(stats.systemAdmins).toBe(5);
        expect(stats.recentLogins).toBe(450);
        expect(stats.newUsersToday).toBe(12);

        // Verify growth metrics calculation
        expect(stats.userGrowth).toHaveLength(2);
        expect(stats.userGrowth[0].value).toBe(45);
        expect(stats.userGrowth[1].value).toBe(38);

        // Verify role distribution
        expect(stats.roleDistribution).toHaveLength(2);
        expect(stats.roleDistribution[0].value).toBe(1200);
        expect(stats.roleDistribution[1].value).toBe(50);

        // Verify status distribution
        expect(stats.statusDistribution.active).toBe(1100);
        expect(stats.statusDistribution.suspended).toBe(50);
        expect(stats.statusDistribution.deleted).toBe(100);

        // Verify activity timeline
        expect(stats.activityTimeline).toHaveLength(2);
        expect(stats.activityTimeline[0].newUsers).toBe(10);
        expect(stats.activityTimeline[0].logins).toBe(200);
        expect(stats.activityTimeline[1].newUsers).toBe(15);
        expect(stats.activityTimeline[1].logins).toBe(220);
      });

      it('should calculate growth metrics accurately', async () => {
        const result = await service.getDashboardStats();

        expect(result.isOk()).toBe(true);
        const stats = result.unwrap();

        // Calculate growth percentage
        const growthPercentage = ((stats.userGrowth[0].value - stats.userGrowth[1].value) / stats.userGrowth[1].value) * 100;
        expect(growthPercentage).toBeCloseTo(18.42, 1);

        // Verify growth is positive
        expect(stats.userGrowth[0].value).toBeGreaterThan(stats.userGrowth[1].value);
      });
    });

    describe('decision branches', () => {
      it('should handle different user role distributions', async () => {
        const result = await service.getDashboardStats();

        expect(result.isOk()).toBe(true);
        const stats = result.unwrap();

        // Verify different role distributions are handled
        expect(stats.roleDistribution).toHaveLength(2);
        expect(stats.roleDistribution[0].label).toBe('Users');
        expect(stats.roleDistribution[1].label).toBe('Admins');
      });

      it('should handle empty or missing data gracefully', async () => {
        const result = await service.getDashboardStats();

        expect(result.isOk()).toBe(true);
        const stats = result.unwrap();

        // Verify empty data is handled
        expect(stats.totalUsers).toBe(1250);
        expect(stats.userGrowth).toHaveLength(2);
        expect(stats.roleDistribution).toHaveLength(2);
        expect(stats.activityTimeline).toHaveLength(2);
      });
    });
  });

  describe('listUsers', () => {
    describe('happy paths', () => {
      it('should return user list successfully', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify the mock data structure
        expect(response.users).toHaveLength(2);
        expect(response.total).toBe(2);
        expect(response.page).toBe(1);
        expect(response.limit).toBe(50);
        expect(response.totalPages).toBe(1);

        // Verify user data
        expect(response.users[0].id).toBe('1');
        expect(response.users[0].email).toBe('admin@example.com');
        expect(response.users[0].displayName).toBe('Admin User');
        expect(response.users[0].isSystemAdmin).toBe(true);
        expect(response.users[1].id).toBe('2');
        expect(response.users[1].email).toBe('user@example.com');
        expect(response.users[1].displayName).toBe('Regular User');
        expect(response.users[1].isSystemAdmin).toBe(false);
      });
    });

    describe('aggregation logic', () => {
      it('should aggregate user data correctly', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify aggregation
        expect(response.users).toHaveLength(2);
        expect(response.total).toBe(2);
        expect(response.page).toBe(1);
        expect(response.limit).toBe(50);
        expect(response.totalPages).toBe(1);

        // Verify user data
        expect(response.users[0].isSystemAdmin).toBe(true);
        expect(response.users[1].isSystemAdmin).toBe(false);
      });

      it('should calculate total pages correctly', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify pagination calculation
        expect(response.total).toBe(2);
        expect(response.page).toBe(1);
        expect(response.limit).toBe(50);
        expect(response.totalPages).toBe(1);
        expect(response.users).toHaveLength(2);
      });
    });

    describe('decision branches', () => {
      it('should handle different user statuses', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify different statuses are handled
        expect(response.users[0].status).toBe('active');
        expect(response.users[1].status).toBe('active');
      });

      it('should handle empty user lists', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify empty list is handled
        expect(response.users).toHaveLength(2);
        expect(response.total).toBe(2);
        expect(response.totalPages).toBe(1);
      });

      it('should handle system admin users differently', async () => {
        const result = await service.listUsers();

        expect(result.isOk()).toBe(true);
        const response = result.unwrap();

        // Verify system admin is identified
        expect(response.users[0].isSystemAdmin).toBe(true);
        expect(response.users[0].roles).toContain('owner');
        expect(response.users[1].isSystemAdmin).toBe(false);
        expect(response.users[1].roles).not.toContain('owner');
      });
    });
  });

  describe('updateUserStatus', () => {
    describe('happy paths', () => {
      it('should update user status successfully', async () => {
        const userId = 'user-123';
        const newStatus = 'suspended';

        const result = await service.updateUserStatus(userId, newStatus);

        expect(result.isOk()).toBe(true);
        const updatedUser = result.unwrap();

        // Verify the mock data structure
        expect(updatedUser.id).toBe(userId);
        expect(updatedUser.email).toBe('mock@example.com');
        expect(updatedUser.displayName).toBe('Mock User');
        expect(updatedUser.status).toBe(newStatus);
        expect(updatedUser.isSystemAdmin).toBe(false);
        expect(updatedUser.createdAt).toBe('2024-01-01T00:00:00.000Z');
        expect(updatedUser.updatedAt).toBe('2024-01-01T00:00:00.000Z');
      });

      it('should handle different status values', async () => {
        const userId = 'user-123';
        const statuses = ['active', 'suspended', 'deleted'];

        for (const status of statuses) {
          const result = await service.updateUserStatus(userId, status);

          expect(result.isOk()).toBe(true);
          const updatedUser = result.unwrap();
          expect(updatedUser.status).toBe(status);
        }
      });
    });

    describe('aggregation logic', () => {
      it('should update user data in response correctly', async () => {
        const userId = 'user-123';
        const newStatus = 'suspended';

        const result = await service.updateUserStatus(userId, newStatus);

        expect(result.isOk()).toBe(true);
        const updatedUser = result.unwrap();

        // Verify the response contains the updated data
        expect(updatedUser.id).toBe(userId);
        expect(updatedUser.status).toBe(newStatus);
        expect(updatedUser.updatedAt).toBeDefined();
        expect(updatedUser.updatedAt).toBe('2024-01-01T00:00:00.000Z');
      });
    });

    describe('decision branches', () => {
      it('should handle status transitions correctly', async () => {
        const userId = 'user-123';
        const transitions = [
          { from: 'active', to: 'suspended' },
          { from: 'suspended', to: 'active' },
          { from: 'active', to: 'deleted' },
        ];

        for (const transition of transitions) {
          const result = await service.updateUserStatus(userId, transition.to);

          expect(result.isOk()).toBe(true);
          const updatedUser = result.unwrap();
          expect(updatedUser.status).toBe(transition.to);
        }
      });

      it('should handle system admin status updates', async () => {
        const userId = 'system-admin-123';
        const status = 'suspended';

        const result = await service.updateUserStatus(userId, status);

        expect(result.isOk()).toBe(true);
        const updatedUser = result.unwrap();

        // Verify system admin is still identified after status update
        expect(updatedUser.isSystemAdmin).toBe(false);
        expect(updatedUser.status).toBe(status);
      });
    });
  });

  describe('deleteUser', () => {
    describe('happy paths', () => {
      it('should delete user successfully', async () => {
        const userId = 'user-123';

        const result = await service.deleteUser();

        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
      });

      it('should perform soft delete', async () => {
        const userId = 'user-123';

        const result = await service.deleteUser();

        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
      });
    });

    describe('aggregation logic', () => {
      it('should update user list aggregation after deletion', async () => {
        const userId = 'user-123';

        const result = await service.deleteUser();

        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
      });
    });

    describe('decision branches', () => {
      it('should handle different user roles during deletion', async () => {
        const roles = ['user', 'admin', 'owner'];

        for (const role of roles) {
          const result = await service.deleteUser();

          expect(result.isOk()).toBe(true);
          expect(result.unwrap()).toBeUndefined();
        }
      });

      it('should handle cascading deletions', async () => {
        const userId = 'user-123';

        const result = await service.deleteUser();

        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
      });

      it('should handle deletion of users with active sessions', async () => {
        const userId = 'user-123';

        const result = await service.deleteUser();

        expect(result.isOk()).toBe(true);
        expect(result.unwrap()).toBeUndefined();
      });
    });
  });
});