package com.sinata.appointment.service;

import com.sinata.appointment.config.LocalFileUploadProperties;
import com.sinata.appointment.constants.BizErrorCode;
import com.sinata.appointment.exception.BizException;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.Set;
import java.util.UUID;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;
import org.springframework.web.multipart.MultipartFile;

@Service
@Slf4j
public class LocalImageUploadService {

    private static final long IMAGE_MAX_SIZE = 10L * 1024 * 1024;
    private static final Set<String> IMAGE_EXTENSIONS = Set.of(".jpg", ".jpeg", ".png", ".webp", ".gif");

    private final LocalFileUploadProperties localFileUploadProperties;

    public LocalImageUploadService(LocalFileUploadProperties localFileUploadProperties) {
        this.localFileUploadProperties = localFileUploadProperties;
    }

    public String uploadImage(MultipartFile file) {
        if (file == null || file.isEmpty()) {
            throw new BizException(BizErrorCode.AUTH_INVALID_CREDENTIALS, "图片文件不能为空");
        }
        if (file.getSize() > IMAGE_MAX_SIZE) {
            throw new BizException(BizErrorCode.AUTH_INVALID_CREDENTIALS, "图片文件不能超过10MB");
        }
        String ext = normalizeImageExtension(file.getOriginalFilename(), file.getContentType());
        String fileName = UUID.randomUUID().toString().replace("-", "") + ext;
        Path uploadDir = Path.of(localFileUploadProperties.getFileUploadPath()).toAbsolutePath().normalize();
        Path target = uploadDir.resolve(fileName).normalize();
        if (!target.getParent().equals(uploadDir)) {
            throw new BizException(BizErrorCode.AUTH_FORBIDDEN, "图片上传路径非法");
        }
        try {
            Files.createDirectories(uploadDir);
            Files.copy(file.getInputStream(), target, StandardCopyOption.REPLACE_EXISTING);
        } catch (IOException ex) {
            throw new BizException(BizErrorCode.AUTH_FORBIDDEN, "图片上传失败");
        }
        String url = buildPictureUrl(fileName);
        log.info("local image uploaded. path={} url={}", target, url);
        return url;
    }

    private String buildPictureUrl(String fileName) {
        String serverAddress = localFileUploadProperties.getPictureServerAddress();
        if (!StringUtils.hasText(serverAddress)) {
            return fileName;
        }
        return serverAddress.endsWith("/") ? serverAddress + fileName : serverAddress + "/" + fileName;
    }

    private String normalizeImageExtension(String originalFilename, String contentType) {
        String ext = "";
        if (StringUtils.hasText(originalFilename)) {
            int idx = originalFilename.lastIndexOf('.');
            if (idx >= 0) {
                ext = originalFilename.substring(idx).toLowerCase();
            }
        }
        if (!IMAGE_EXTENSIONS.contains(ext)) {
            ext = switch (contentType == null ? "" : contentType.toLowerCase()) {
                case "image/jpeg", "image/jpg" -> ".jpg";
                case "image/png" -> ".png";
                case "image/webp" -> ".webp";
                case "image/gif" -> ".gif";
                default -> "";
            };
        }
        if (!IMAGE_EXTENSIONS.contains(ext)) {
            throw new BizException(BizErrorCode.AUTH_INVALID_CREDENTIALS, "仅支持 jpg、jpeg、png、webp、gif 图片");
        }
        return ext;
    }
}