package com.gcsc.guide.service;

import com.gcsc.guide.dto.RoleResponse;
import com.gcsc.guide.entity.Role;
import com.gcsc.guide.entity.RoleUrlPattern;
import com.gcsc.guide.exception.BusinessException;
import com.gcsc.guide.exception.ResourceNotFoundException;
import com.gcsc.guide.repository.RoleRepository;
import com.gcsc.guide.repository.RoleUrlPatternRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@RequiredArgsConstructor
public class RoleService {

    private final RoleRepository roleRepository;
    private final RoleUrlPatternRepository roleUrlPatternRepository;

    @Transactional(readOnly = true)
    public List<RoleResponse> getRoles() {
        return roleRepository.findAllWithUrlPatterns().stream()
            .map(RoleResponse::from)
            .toList();
    }

    @Transactional
    public RoleResponse createRole(String name, String description) {
        roleRepository.findByName(name).ifPresent(r -> {
            throw new BusinessException("이미 존재하는 롤 이름입니다: " + name);
        });
        Role role = new Role(name, description);
        return RoleResponse.from(roleRepository.save(role));
    }

    @Transactional
    public RoleResponse updateRole(Long roleId, String name, String description) {
        Role role = findRoleById(roleId);
        roleRepository.findByName(name)
            .filter(r -> !r.getId().equals(roleId))
            .ifPresent(r -> {
                throw new BusinessException("이미 존재하는 롤 이름입니다: " + name);
            });
        role.update(name, description);
        return RoleResponse.from(roleRepository.save(role));
    }

    @Transactional
    public void deleteRole(Long roleId) {
        if (!roleRepository.existsById(roleId)) {
            throw new ResourceNotFoundException("롤", roleId);
        }
        roleRepository.deleteById(roleId);
    }

    @Transactional(readOnly = true)
    public List<String> getPermissions(Long roleId) {
        Role role = roleRepository.findByIdWithUrlPatterns(roleId)
            .orElseThrow(() -> new ResourceNotFoundException("롤", roleId));
        return role.getUrlPatterns().stream()
            .map(RoleUrlPattern::getUrlPattern)
            .toList();
    }

    @Transactional
    public RoleResponse addPermission(Long roleId, String urlPattern) {
        Role role = roleRepository.findByIdWithUrlPatterns(roleId)
            .orElseThrow(() -> new ResourceNotFoundException("롤", roleId));
        role.getUrlPatterns().add(new RoleUrlPattern(role, urlPattern));
        return RoleResponse.from(roleRepository.save(role));
    }

    @Transactional
    public void deletePermission(Long permissionId) {
        if (!roleUrlPatternRepository.existsById(permissionId)) {
            throw new ResourceNotFoundException("권한", permissionId);
        }
        roleUrlPatternRepository.deleteById(permissionId);
    }

    private Role findRoleById(Long roleId) {
        return roleRepository.findById(roleId)
            .orElseThrow(() -> new ResourceNotFoundException("롤", roleId));
    }
}