package com.social.media.application.user.handler;

import com.social.media.application.user.command.DeleteUserCommand;
import com.social.media.domain.user.aggregate.User;
import com.social.media.domain.user.repository.UserRepository;
import com.social.media.domain.user.service.UserDomainService;
import com.social.media.domain.shared.exception.BusinessRuleViolationException;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

/**
 * Handler for DeleteUserCommand - performs logical deletion
 */
@Service
public class DeleteUserCommandHandler {
    
    private final UserRepository userRepository;
    private final UserDomainService userDomainService;
    
    public DeleteUserCommandHandler(UserRepository userRepository, UserDomainService userDomainService) {
        this.userRepository = userRepository;
        this.userDomainService = userDomainService;
    }
    
    @Transactional
    public void handle(DeleteUserCommand command) {
        User user = userRepository.findById(command.userId())
            .orElseThrow(() -> new BusinessRuleViolationException("User not found with ID: " + command.userId()));
        
        // Check if user is already deleted
        if (user.isDeleted()) {
            throw new BusinessRuleViolationException("User is already deleted");
        }
        
        // Get user performing the deletion for validation
        User deletedBy = null;
        if (command.deletedBy() != null) {
            deletedBy = userRepository.findById(command.deletedBy())
                .orElseThrow(() -> new BusinessRuleViolationException("Deleting user not found"));
        }
        
        // Validate deletion rules using domain service
        userDomainService.validateUserDeletion(user, deletedBy);
        
        // Perform logical deletion
        user.softDelete();
        userRepository.save(user);
    }
}
