package com.yj.earth.business.controller;

import cn.hutool.core.io.FileUtil;
import cn.hutool.core.util.IdUtil;
import com.drew.imaging.ImageMetadataReader;
import com.drew.imaging.ImageProcessingException;
import com.drew.lang.Rational;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.*;

import cn.hutool.crypto.digest.DigestUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.drew.metadata.MetadataException;
import com.drew.metadata.exif.GpsDirectory;
import com.yj.earth.annotation.CheckAuth;
import com.yj.earth.business.domain.FileInfo;
import com.yj.earth.business.service.FileInfoService;
import com.yj.earth.common.util.ApiResponse;
import com.yj.earth.common.util.JsonUtil;
import com.yj.earth.vo.FileInfoVo;
import io.swagger.v3.oas.annotations.Operation;
import io.swagger.v3.oas.annotations.Parameter;
import io.swagger.v3.oas.annotations.tags.Tag;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.http.HttpHeaders;
import org.springframework.util.DigestUtils;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import java.io.InputStream;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Map;

@Tag(name = "文件数据管理")
@CheckAuth
@RestController
@RequestMapping("/fileInfo")
public class FileInfoController {

    @Resource
    private FileInfoService fileInfoService;

    @Operation(summary = "文件上传")
    @PostMapping("/upload")
    public ApiResponse uploadFiles(@Parameter(description = "上传的文件数组", required = true) @RequestParam("files") MultipartFile[] files) throws IOException {
        // 校验文件数组是否为空
        if (files == null || files.length == 0) {
            return ApiResponse.failure("上传文件不能为空");
        }
        // 获取完整的上传目录路径
        String fullUploadPath = fileInfoService.getFullUploadPath();
        List<FileInfoVo> fileInfoVoList = new ArrayList<>();
        // 遍历处理每个文件
        for (MultipartFile file : files) {
            // 跳过空文件
            if (file.isEmpty()) {
                continue;
            }
            // 获取原始文件名和后缀
            String originalFilename = file.getOriginalFilename();
            String fileSuffix = FileUtil.extName(originalFilename);
            String contentType = file.getContentType();

            // 生成唯一文件名、避免重复
            String uniqueFileName = IdUtil.simpleUUID() + "." + fileSuffix;

            // 创建文件存储目录（如果不存在则自动创建）
            File uploadDir = new File(fullUploadPath);
            FileUtil.mkdir(uploadDir);

            // 构建完整文件路径
            String filePath = fullUploadPath + File.separator + uniqueFileName;
            File destFile = new File(filePath);

            // 使用Hutool工具类保存文件
            FileUtil.writeBytes(file.getBytes(), destFile);

            // 计算文件MD5（用于校验文件完整性）
            String fileMd5 = DigestUtil.md5Hex(destFile);

            // 查询有没有文件名一样并且 MD5 也一样的数据
            LambdaQueryWrapper<FileInfo> queryWrapper = new LambdaQueryWrapper<>();
            queryWrapper.eq(FileInfo::getFileName, originalFilename).eq(FileInfo::getFileMd5, fileMd5);
            if (fileInfoService.count(queryWrapper) > 0) {
                return ApiResponse.failure("已存在文件名相同且内容完全一致的文件");
            }

            // 保存文件信息到数据库
            FileInfo fileInfo = new FileInfo();
            fileInfo.setFileName(originalFilename);
            fileInfo.setFileSuffix(fileSuffix);
            fileInfo.setContentType(contentType);
            fileInfo.setFileSize(file.getSize());
            fileInfo.setFilePath(uniqueFileName);
            fileInfo.setFileMd5(fileMd5);

            // 保存文件信息并获取ID
            fileInfoService.save(fileInfo);

            // 构建并设置预览URL和下载URL
            String previewUrl = "/fileInfo/preview/" + fileInfo.getId();
            String downloadUrl = "/fileInfo/download/" + fileInfo.getId();

            FileInfoVo fileInfoVo = new FileInfoVo();
            BeanUtils.copyProperties(fileInfo, fileInfoVo);
            fileInfoVo.setPreviewUrl(previewUrl);
            fileInfoVo.setDownloadUrl(downloadUrl);

            fileInfoVoList.add(fileInfoVo);
        }

        if (fileInfoVoList.isEmpty()) {
            return ApiResponse.failure("未成功上传任何文件");
        }

        return ApiResponse.success(fileInfoVoList);
    }

    @Operation(summary = "文件下载")
    @GetMapping("/download/{id}")
    public void downloadFile(@Parameter(description = "文件ID", required = true) @PathVariable String id, HttpServletResponse response) throws IOException {
        // 根据ID查询文件信息
        FileInfo fileInfo = fileInfoService.getById(id);
        if (fileInfo == null) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        // 构建完整文件路径
        String fullPath = fileInfoService.getFullUploadPath() + File.separator + fileInfo.getFilePath();
        File file = new File(fullPath);

        // 校验文件是否存在
        if (!file.exists()) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        // 设置响应头
        response.setContentType(fileInfo.getContentType());
        response.setContentLengthLong(fileInfo.getFileSize());
        String encodedFileName = URLEncoder.encode(fileInfo.getFileName(), StandardCharsets.UTF_8.name());
        response.setHeader(HttpHeaders.CONTENT_DISPOSITION,
                "attachment; filename=\"" + encodedFileName + "\"; filename*=UTF-8''" + encodedFileName);

        // 使用 Hutool 工具类复制文件流到响应输出流
        try (OutputStream os = response.getOutputStream()) {
            FileUtil.writeToStream(file, os);
        }
    }

    @Operation(summary = "文件预览")
    @GetMapping("/preview/{id}")
    public void previewFile(@Parameter(description = "文件ID", required = true) @PathVariable String id, HttpServletResponse response) throws IOException {
        // 根据ID查询文件信息
        FileInfo fileInfo = fileInfoService.getById(id);
        if (fileInfo == null) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        // 构建完整文件路径
        String fullPath = fileInfoService.getFullUploadPath() + File.separator + fileInfo.getFilePath();
        File file = new File(fullPath);

        // 校验文件是否存在
        if (!file.exists()) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        // 设置响应头（不设置 attachment、让浏览器直接显示）
        response.setContentType(fileInfo.getContentType());
        response.setContentLengthLong(fileInfo.getFileSize());

        // 使用 Hutool 工具类复制文件流到响应输出流
        try (OutputStream os = response.getOutputStream()) {
            FileUtil.writeToStream(file, os);
        }
    }

    @Operation(summary = "本地文件预览")
    @GetMapping("/previewLocal")
    public void previewLocalFile(@Parameter(description = "本地文件绝对路径") @RequestParam String fileAbsolutePath, HttpServletResponse response) {
        Path targetFilePath = null;
        try {
            // 标准化路径
            targetFilePath = Paths.get(fileAbsolutePath).toRealPath();

            // 校验文件合法性：是否存在、是否为普通文件
            BasicFileAttributes fileAttr = Files.readAttributes(targetFilePath, BasicFileAttributes.class);
            if (!fileAttr.isRegularFile()) {
                response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
                fileInfoService.writeResponseMessage(response, "目标路径不是有效的文件");
                return;
            }

            // 设置预览响应头
            String fileName = targetFilePath.getFileName().toString();
            String encodedFileName = URLEncoder.encode(fileName, StandardCharsets.UTF_8.name());
            String contentType = Files.probeContentType(targetFilePath);

            // 对于文本类型文件、指定字符编码
            if (contentType != null && contentType.startsWith("text/")) {
                response.setContentType(contentType + "; charset=UTF-8");
            } else {
                response.setContentType(contentType != null ? contentType : "application/octet-stream");
            }

            response.setContentLengthLong(fileAttr.size());
            // 关键修改：将attachment改为inline实现预览
            response.setHeader(HttpHeaders.CONTENT_DISPOSITION,
                    "inline; filename=\"" + encodedFileName + "\"; filename*=UTF-8''" + encodedFileName);

            // 写入文件流
            try (InputStream inputStream = Files.newInputStream(targetFilePath);
                 OutputStream outputStream = response.getOutputStream()) {
                byte[] buffer = new byte[1024 * 8];
                int len;
                while ((len = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, len);
                }
                outputStream.flush();
            }

        } catch (NoSuchFileException e) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            fileInfoService.writeResponseMessage(response, "文件不存在：" + fileAbsolutePath);
        } catch (SecurityException e) {
            response.setStatus(HttpServletResponse.SC_FORBIDDEN);
            fileInfoService.writeResponseMessage(response, "访问拒绝：无权限读取该文件");
        } catch (Exception e) {
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            fileInfoService.writeResponseMessage(response, "预览失败：" + e.getMessage());
        }
    }
}