package com.nq.service.impl;

import com.google.common.collect.Lists;
import com.nq.common.ServerResponse;
import com.nq.service.IFileUploadService;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;
import java.util.UUID;

import com.nq.utils.PropertiesUtil;
import com.nq.utils.ftp.FTPUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;


@Service("iFileUploadService")

public class FileUploadServiceImpl

        implements IFileUploadService {

    private static final Logger log = LoggerFactory.getLogger(FileUploadServiceImpl.class);


    public ServerResponse upload(MultipartFile file, String path) {
        path = PropertiesUtil.getProperty("ftp.address");
        // 参数校验
        if (file == null || file.isEmpty()) {
            return ServerResponse.createByErrorMsg("文件不能为空");
        }

        try {
            // 获取原始文件名
            String fileName = file.getOriginalFilename();
            if (fileName == null || fileName.trim().isEmpty()) {
                return ServerResponse.createByErrorMsg("文件名无效");
            }

            // 安全地获取文件扩展名
            String fileExtensionName = "";
            int lastDotIndex = fileName.lastIndexOf(".");
            if (lastDotIndex > 0 && lastDotIndex < fileName.length() - 1) {
                fileExtensionName = fileName.substring(lastDotIndex + 1).toLowerCase();
            } else {
                return ServerResponse.createByErrorMsg("文件格式错误，无法识别扩展名");
            }

            // 验证文件扩展名是否合法
            if (!isValidFileExtension(fileExtensionName)) {
                return ServerResponse.createByErrorMsg("不支持的文件类型: " + fileExtensionName);
            }

            // 生成唯一文件名：时间戳 + 随机数
            String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss_SSS").format(new Date());
            int randomNum = new Random().nextInt(99999);
            String uploadFileName = timeStamp + "_" + String.format("%05d", randomNum) + "." + fileExtensionName;

            // 确保目标目录存在
            File targetDir = new File(path);
            if (!targetDir.exists()) {
                if (!targetDir.mkdirs()) {
                    return ServerResponse.createByErrorMsg("无法创建上传目录");
                }
            }

            // 创建目标文件
            File targetFile = new File(targetDir, uploadFileName);

            // 保存文件
            file.transferTo(targetFile);

            // 验证文件是否成功保存
            if (!targetFile.exists() || targetFile.length() == 0) {
                return ServerResponse.createByErrorMsg("文件保存失败");
            }

            return ServerResponse.createBySuccess(uploadFileName);

        } catch (IOException e) {
            e.printStackTrace();
            return ServerResponse.createByErrorMsg("文件上传失败: " + e.getMessage());
        } catch (Exception e) {
            e.printStackTrace();
            return ServerResponse.createByErrorMsg("上传过程发生异常: " + e.getMessage());
        }
    }

    /**
     * 验证文件扩展名是否合法
     */
    private boolean isValidFileExtension(String fileExtension) {
        if (fileExtension == null || fileExtension.trim().isEmpty()) {
            return false;
        }

        // 定义允许的文件类型
        String[] allowedExtensions = {
                "jpg", "jpeg", "png"
        };

        for (String allowedExt : allowedExtensions) {
            if (allowedExt.equalsIgnoreCase(fileExtension)) {
                return true;
            }
        }

        return false;
    }

}