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.metadata.Directory;
import com.drew.metadata.Metadata;

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

import cn.hutool.crypto.digest.DigestUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
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")
@RestController
@RequestMapping("/fileInfo")
public class FileInfoController {

    @Resource
    private FileInfoService fileInfoService;

    @Value("${file.upload.path}")
    private String uploadPath;

    // 获取项目根目录
    private String getProjectRootPath() {
        return System.getProperty("user.dir");
    }

    // 获取完整的上传目录路径
    private String getFullUploadPath() {
        // 拼接项目根目录和配置的上传路径
        return getProjectRootPath() + File.separator + uploadPath;
    }

    @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 = 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) {  // 修复了此处的bug、添加了queryWrapper参数
                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);  // 只保存相对文件名、不保存完整路径
            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 = 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 = 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);
        }
    }

    public String handleLocationImageUpload(MultipartFile file) {
        try {
            // 校验文件是否为空
            if (file.isEmpty()) {
                throw new IllegalArgumentException("上传文件不能为空");
            }
            // 获取文件基本信息
            String originalFilename = file.getOriginalFilename();
            String fileSuffix = FileUtil.extName(originalFilename);
            String contentType = file.getContentType();
            // 验证是否为图片文件
            if (contentType == null || !contentType.startsWith("image/")) {
                throw new IllegalArgumentException("请上传图片文件");
            }
            // 获取完整的上传目录路径
            Path fullUploadPath = Paths.get(getFullUploadPath());
            // 生成唯一文件名
            String uniqueFileName = UUID.randomUUID().toString().replaceAll("-", "") + "." + fileSuffix;
            // 创建文件存储目录
            Files.createDirectories(fullUploadPath);
            // 构建完整文件路径并保存文件
            Path destFilePath = fullUploadPath.resolve(uniqueFileName);
            // 先将文件保存到目标位置
            file.transferTo(destFilePath);
            // 计算文件MD5（使用已保存的文件）
            String fileMd5 = calculateFileMd5(destFilePath.toFile());
            // 检查文件是否已存在
            LambdaQueryWrapper<FileInfo> queryWrapper = new LambdaQueryWrapper<>();
            queryWrapper.eq(FileInfo::getFileName, originalFilename)
                    .eq(FileInfo::getFileMd5, fileMd5);
            if (fileInfoService.count(queryWrapper) > 0) {
                throw new IllegalStateException("已存在相同的图片文件");
            }
            // 提取图片元数据（使用已保存的文件，避免使用临时文件）
            Map<String, Object> metadata;
            try (InputStream is = Files.newInputStream(destFilePath)) {
                metadata = extractImageMetadata(is);
            }
            // 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);
            fileInfoService.save(fileInfo);
            // 构建并返回结果
            Map<String, Object> result = new HashMap<>();
            result.put("previewUrl", "/fileInfo/preview/" + fileInfo.getId());
            result.put("downloadUrl", "/fileInfo/download/" + fileInfo.getId());
            result.put("metadata", metadata);
            return JsonUtil.mapToJson(result);
        } catch (IOException e) {
            throw new RuntimeException("文件上传失败: " + e.getMessage(), e);
        }
    }

    /**
     * 计算文件的 MD5
     */
    private String calculateFileMd5(File file) throws IOException {
        try (InputStream is = new FileInputStream(file)) {
            return DigestUtils.md5DigestAsHex(is);
        }
    }

    /**
     * 提取图片的EXIF元数据（包括定位信息）
     */
    private Map<String, Object> extractImageMetadata(InputStream inputStream) {
        try {
            Map<String, Object> result = new HashMap<>();
            Metadata metadata = ImageMetadataReader.readMetadata(inputStream);

            // 遍历所有元数据目录
            for (Directory directory : metadata.getDirectories()) {
                String directoryName = directory.getName();
                Map<String, String> directoryTags = new HashMap<>();

                // 提取当前目录下的所有标签
                for (com.drew.metadata.Tag tag : directory.getTags()) {
                    directoryTags.put(tag.getTagName(), tag.getDescription());
                }

                // 存储当前目录的所有标签
                if (!directoryTags.isEmpty()) {
                    result.put(directoryName, directoryTags);
                }
            }

            return result;
        } catch (ImageProcessingException | IOException e) {
            return Collections.emptyMap();
        }
    }
}