package com.designhub.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.designhub.entity.FileUpload;
import com.designhub.entity.S3Config;
import com.designhub.mapper.FileUploadMapper;
import com.designhub.mapper.S3ConfigMapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import software.amazon.awssdk.auth.credentials.AwsBasicCredentials;
import software.amazon.awssdk.auth.credentials.StaticCredentialsProvider;
import software.amazon.awssdk.core.sync.RequestBody;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.s3.S3Client;
import software.amazon.awssdk.services.s3.S3Configuration;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.URI;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.UUID;
import net.coobird.thumbnailator.Thumbnails;

/**
 * S3文件存储服务
 */
@Service
public class S3Service {

    private static final Logger log = LoggerFactory.getLogger(S3Service.class);

    @Autowired
    private S3ConfigMapper s3ConfigMapper;

    @Autowired
    private FileUploadMapper fileUploadMapper;

    /**
     * 上传文件到S3
     * 
     * @param file 文件
     * @param uploaderId 上传者ID
     * @param uploaderName 上传者姓名
     * @param relatedType 关联类型
     * @param relatedId 关联ID
     * @return 文件URL
     */
    public String uploadFile(MultipartFile file, Long uploaderId, String uploaderName, 
                            String relatedType, Long relatedId) throws IOException {
        // 获取激活的S3配置
        S3Config config = s3ConfigMapper.getActiveConfig();
        if (config == null) {
            throw new RuntimeException("S3配置未激活，请先配置S3存储");
        }

        // 生成唯一文件名
        String originalFilename = file.getOriginalFilename();
        String fileExtension = originalFilename.substring(originalFilename.lastIndexOf("."));
        String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
        String uuid = UUID.randomUUID().toString().replace("-", "").substring(0, 8);
        String storedName = timestamp + "_" + uuid + fileExtension;

        // 构建文件路径
        String filePath = config.getFilePath() + storedName;

        try {
            // 创建S3客户端
            S3Client s3Client = createS3Client(config);

            // 上传文件
            PutObjectRequest putObjectRequest = PutObjectRequest.builder()
                    .bucket(config.getBucket())
                    .key(filePath)
                    .contentType(file.getContentType())
                    .build();

            s3Client.putObject(putObjectRequest, RequestBody.fromInputStream(file.getInputStream(), file.getSize()));

            // 生成文件URL
            String fileUrl = config.getPublicDomain() + "/" + filePath;

            // 保存文件上传记录
            FileUpload fileUpload = new FileUpload();
            fileUpload.setOriginalName(originalFilename);
            fileUpload.setStoredName(storedName);
            fileUpload.setFilePath(filePath);
            fileUpload.setFileUrl(fileUrl);
            fileUpload.setFileSize(file.getSize());
            fileUpload.setFileType(file.getContentType());
            fileUpload.setUploaderId(uploaderId);
            fileUpload.setUploaderName(uploaderName);
            fileUpload.setRelatedType(relatedType);
            fileUpload.setRelatedId(relatedId);
            fileUploadMapper.insert(fileUpload);

            log.info("文件上传成功: {} -> {}", originalFilename, fileUrl);
            return fileUrl;

        } catch (Exception e) {
            log.error("文件上传失败: {}", originalFilename, e);
            throw new RuntimeException("文件上传失败: " + e.getMessage());
        }
    }

    /**
     * 创建S3客户端
     */
    private S3Client createS3Client(S3Config config) {
        AwsBasicCredentials credentials = AwsBasicCredentials.create(
                config.getAccessKeyId(),
                config.getSecretAccessKey()
        );

        S3Configuration s3Config = S3Configuration.builder()
                .pathStyleAccessEnabled(config.getEnablePathStyle())
                .build();

        return S3Client.builder()
                .region(Region.of(config.getRegion()))
                .credentialsProvider(StaticCredentialsProvider.create(credentials))
                .endpointOverride(URI.create(config.getEndpoint()))
                .serviceConfiguration(s3Config)
                .build();
    }

    /**
     * 获取文件上传记录
     */
    public FileUpload getFileUploadById(Long id) {
        return fileUploadMapper.selectById(id);
    }

    /**
     * 根据关联信息获取文件列表
     */
    public java.util.List<FileUpload> getFilesByRelated(String relatedType, Long relatedId) {
        LambdaQueryWrapper<FileUpload> wrapper = new LambdaQueryWrapper<>();
        wrapper.eq(FileUpload::getRelatedType, relatedType)
               .eq(FileUpload::getRelatedId, relatedId)
               .orderByDesc(FileUpload::getCreateTime);
        return fileUploadMapper.selectList(wrapper);
    }

    /**
     * 上传预览图（压缩到最大宽度200px，保持比例）
     * 
     * @param file 图片文件
     * @param uploaderId 上传者ID
     * @param uploaderName 上传者姓名
     * @return 压缩后图片的URL
     */
    public String uploadPreviewImage(MultipartFile file, Long uploaderId, String uploaderName) throws IOException {
        // 获取激活的S3配置
        S3Config config = s3ConfigMapper.getActiveConfig();
        if (config == null) {
            throw new RuntimeException("S3配置未激活，请先配置S3存储");
        }

        // 验证是否为图片
        String contentType = file.getContentType();
        if (contentType == null || !contentType.startsWith("image/")) {
            throw new RuntimeException("只能上传图片文件");
        }

        // 生成唯一文件名
        String originalFilename = file.getOriginalFilename();
        String fileExtension = originalFilename.substring(originalFilename.lastIndexOf("."));
        String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
        String uuid = UUID.randomUUID().toString().replace("-", "").substring(0, 8);
        String storedName = "preview_" + timestamp + "_" + uuid + fileExtension;

        // 构建文件路径（预览图专用目录）
        String filePath = config.getFilePath() + "previews/" + storedName;

        try {
            // 压缩图片到最大宽度200px，保持比例
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            Thumbnails.of(file.getInputStream())
                    .width(200)  // 最大宽度200像素
                    .keepAspectRatio(true)  // 保持比例
                    .outputQuality(0.85)  // 图片质量
                    .toOutputStream(outputStream);

            byte[] compressedBytes = outputStream.toByteArray();

            // 创建S3客户端
            S3Client s3Client = createS3Client(config);

            // 上传压缩后的图片
            PutObjectRequest putObjectRequest = PutObjectRequest.builder()
                    .bucket(config.getBucket())
                    .key(filePath)
                    .contentType(contentType)
                    .build();

            s3Client.putObject(putObjectRequest, 
                    RequestBody.fromInputStream(new ByteArrayInputStream(compressedBytes), compressedBytes.length));

            // 生成文件URL
            String fileUrl = config.getPublicDomain() + "/" + filePath;

            // 保存文件上传记录
            FileUpload fileUpload = new FileUpload();
            fileUpload.setOriginalName(originalFilename);
            fileUpload.setStoredName(storedName);
            fileUpload.setFilePath(filePath);
            fileUpload.setFileUrl(fileUrl);
            fileUpload.setFileSize((long) compressedBytes.length);
            fileUpload.setFileType(contentType);
            fileUpload.setUploaderId(uploaderId);
            fileUpload.setUploaderName(uploaderName);
            fileUpload.setRelatedType("preview_image");
            fileUploadMapper.insert(fileUpload);

            log.info("预览图上传成功: {} -> {} (压缩后大小: {} bytes)", originalFilename, fileUrl, compressedBytes.length);
            return fileUrl;

        } catch (Exception e) {
            log.error("预览图上传失败: {}", originalFilename, e);
            throw new RuntimeException("预览图上传失败: " + e.getMessage());
        }
    }
}