package com.xuqm.update.service;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.util.HexFormat;
import java.util.UUID;

@Service
public class UpdateAssetService {

    @Value("${update.upload-dir:/tmp/xuqm-update}")
    private String uploadDir;

    @Value("${update.base-url:https://update.dev.xuqinmin.com}")
    private String baseUrl;

    public String storeAppPackage(MultipartFile apkFile) throws IOException {
        if (apkFile == null || apkFile.isEmpty()) {
            return null;
        }
        String filename = UUID.randomUUID() + "_" + apkFile.getOriginalFilename();
        Path dir = Paths.get(uploadDir, "apk");
        Files.createDirectories(dir);
        Path dest = dir.resolve(filename);
        apkFile.transferTo(dest.toFile());
        return baseUrl + "/files/apk/" + filename;
    }

    public StoredRnBundle storeRnBundle(String appId, String platform, String moduleId, MultipartFile bundle) throws Exception {
        if (bundle == null || bundle.isEmpty()) {
            throw new IllegalArgumentException("bundle file is required");
        }
        String filename = moduleId + "." + platform.toLowerCase() + ".bundle";
        Path dir = Paths.get(uploadDir, "rn", appId, platform.toLowerCase(), moduleId);
        Files.createDirectories(dir);
        Path dest = dir.resolve(filename);

        String md5 = computeMd5(bundle);
        bundle.transferTo(dest.toFile());
        return new StoredRnBundle(dest.toAbsolutePath().toString(), md5);
    }

    private String computeMd5(MultipartFile file) throws Exception {
        MessageDigest digest = MessageDigest.getInstance("MD5");
        try (DigestInputStream dis = new DigestInputStream(file.getInputStream(), digest)) {
            byte[] buf = new byte[8192];
            while (dis.read(buf) != -1) {
                // read fully
            }
        }
        return HexFormat.of().formatHex(digest.digest());
    }

    public record StoredRnBundle(String bundlePath, String md5) {}
}