package com.TinyPro.service.imp;


import com.TinyPro.entity.dto.CreatePermissionDto;
import com.TinyPro.entity.dto.UpdatePermissionDto;
import com.TinyPro.entity.page.PageWrapper;
import com.TinyPro.entity.po.Permission;
import com.TinyPro.entity.po.Role;
import com.TinyPro.entity.vo.PermissionVo;
import com.TinyPro.exception.BusinessException;
import com.TinyPro.service.IPermissionService;
import com.TinyPro.jpa.IPermissionRepository;
import jakarta.persistence.criteria.CriteriaBuilder;
import jakarta.persistence.criteria.Predicate;
import jakarta.persistence.criteria.Root;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.domain.Specification;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;

@Service
public class IPermissionServiceImpl implements IPermissionService {
    @Autowired
    private IPermissionRepository iPermissionRepository;


    @Override
    public ResponseEntity<PermissionVo> create(CreatePermissionDto createPermissionDto, boolean isInit) {
        PermissionVo result = new PermissionVo();
        String name = createPermissionDto.getName();
        String desc = createPermissionDto.getDesc();

        Optional<Permission> existingPermission = iPermissionRepository.findByName(name);

        // 情况1：初始化模式且权限已存在
        if (isInit && existingPermission.isPresent()) {
            BeanUtils.copyProperties(existingPermission.get(), result);
            return ResponseEntity.ok(result);
        }

        // 情况2：非初始化模式且权限已存在
        if (existingPermission.isPresent() && !isInit) {
            throw new BusinessException("exception.permission.exists", HttpStatus.BAD_REQUEST, null);
        }

        // 情况3：创建新权限
        Permission newPermission = new Permission();
        newPermission.setName(name);
        newPermission.setDesc(desc);
        Permission save = iPermissionRepository.save(newPermission);
        BeanUtils.copyProperties(save, result);
        return ResponseEntity.ok(result);
    }

    @Override
    public ResponseEntity<PermissionVo> updatePermission(UpdatePermissionDto updatePermissionDto) {
        PermissionVo result = new PermissionVo();
        Integer id = updatePermissionDto.getId();
        String name = updatePermissionDto.getName();
        String desc = updatePermissionDto.getDesc();

        Permission permission = iPermissionRepository.findById(Long.valueOf(id))
                .orElseThrow(() ->  new BusinessException("exception.permission.notExists", HttpStatus.NOT_FOUND, null));

        permission.setName(name);
        permission.setDesc(desc);
        Permission save = iPermissionRepository.save(permission);
        BeanUtils.copyProperties(save, result);
        return ResponseEntity.ok(result);
    }

    @Override
    public ResponseEntity<PageWrapper<PermissionVo>> findPermissions(Integer page, Integer limit, String name) {
        // 处理分页参数
        boolean unlimited = limit == null || limit <= 0;
        Pageable pageable = unlimited ?
                Pageable.unpaged() :
                PageRequest.of(page == null || page <= 0 ? 0 : page - 1, limit);

        // 执行查询
        Page<Permission> permissionPage;
        Specification<Permission> spec = (root, query, cb) -> {
            List<Predicate> predicates = new ArrayList<>();
            if (StringUtils.isNotEmpty(name)) {
                Predicate namePreidcate = buildLikePredicate(root, cb, "name", name);
                predicates.add(namePreidcate);
            }
            return cb.and(predicates.toArray(new Predicate[0]));
        };
        permissionPage = iPermissionRepository.findAll(spec, pageable);
        List<PermissionVo> permissionVoList = permissionPage.getContent()
                .stream()
                .map(permission -> {
                    PermissionVo vo = new PermissionVo();
                    vo.setId(permission.getId());
                    vo.setName(permission.getName());
                    vo.setDesc(permission.getDesc());
                    return vo;
                })
                .collect(Collectors.toList());
        //转变成pagevo
        // 3. 构造分页结果（关键步骤）
        Page<PermissionVo> result = new PageImpl<>(
                permissionVoList,          // 当前页的数据列表
                pageable,                 // 分页信息（page/size/sort）
                permissionPage.getTotalElements() // 总记录数
        );
        // 转换为VO
        return ResponseEntity.ok(PageWrapper.of(result));
    }

       @Override
    public ResponseEntity<CreatePermissionDto> delPermission(Integer id) {
        CreatePermissionDto result = new CreatePermissionDto();
        Permission permission = iPermissionRepository.findById(Long.valueOf(id))
                .orElseThrow(() ->  new BusinessException("exception.permission.notExists",HttpStatus.NOT_FOUND,null));
        iPermissionRepository.deleteRolePermissionByPermissionId(permission.getId().longValue());
        iPermissionRepository.delete(permission);
        BeanUtils.copyProperties(permission, result);
        return ResponseEntity.ok(result);
    }

    @Override
    public List<Permission> findAllPermission() {
        return iPermissionRepository.findAll();
    }


    private Predicate buildLikePredicate(Root<Permission> root, CriteriaBuilder cb, String field, String input) {
        if (input.contains("%")) {
            if (input.startsWith("%") && input.endsWith("%")) {
                // 包含匹配 LIKE '%value%'
                String value = input.substring(1, input.length() - 1);
                return cb.like(root.get(field), "%" + value + "%");
            } else if (input.startsWith("%")) {
                // 后缀匹配 LIKE '%value'
                String value = input.substring(1);
                return cb.like(root.get(field), "%" + value);
            } else if (input.endsWith("%")) {
                // 前缀匹配 LIKE 'value%'
                String value = input.substring(0, input.length() - 1);
                return cb.like(root.get(field), value + "%");
            } else {
                // 如果包含 % 但不以 % 开头或结尾，可以根据需求处理
                // 这里简单地将所有 % 视为通配符，您可以根据需要调整
                return cb.like(root.get(field), input);
            }
        } else {
            // 精确匹配 =
            return cb.equal(root.get(field), input);
        }
    }


}