package com.youlai.boot.common.util;

import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class HashUtils {

    public static String calculateMultipartFileMd5(MultipartFile file) throws NoSuchAlgorithmException, IOException {
        MessageDigest digest = MessageDigest.getInstance("MD5");
        // 使用try-with-resources自动管理输入流
        try (InputStream inputStream = file.getInputStream()) {
            byte[] buffer = new byte[4096]; // 统一缓冲区大小为4KB
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                digest.update(buffer, 0, bytesRead);
            }
        }
        byte[] hashBytes = digest.digest();
        return bytesToHex(hashBytes); // 复用现有工具方法
    }

    /**
     * 计算 MultipartFile 的 SHA1 哈希值
     *
     * @param file 上传的文件
     * @return SHA1 哈希值（小写十六进制字符串）
     * @throws NoSuchAlgorithmException 算法不存在异常
     * @throws IOException IO异常
     */
    public static String calculateMultipartFileSha1(MultipartFile file) throws NoSuchAlgorithmException, IOException {
        MessageDigest digest = MessageDigest.getInstance("SHA-1");
        try (InputStream inputStream = file.getInputStream()) {
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                digest.update(buffer, 0, bytesRead);
            }
        }
        byte[] hashBytes = digest.digest();
        return bytesToHex(hashBytes);
    }

    /**
     * 计算 MultipartFile 的 SHA256 哈希值
     *
     * @param file 上传的文件
     * @return SHA256 哈希值（小写十六进制字符串）
     * @throws NoSuchAlgorithmException 算法不存在异常
     * @throws IOException IO异常
     */
    public static String calculateMultipartFileSha256(MultipartFile file) throws NoSuchAlgorithmException, IOException {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        try (InputStream inputStream = file.getInputStream()) {
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                digest.update(buffer, 0, bytesRead);
            }
        }
        byte[] hashBytes = digest.digest();
        return bytesToHex(hashBytes);
    }

    public static String getFileMD5(File file) throws NoSuchAlgorithmException, IOException {
        MessageDigest md = MessageDigest.getInstance("MD5");
        FileInputStream fis = new FileInputStream(file);
        byte[] dataBytes = new byte[1024];

        int bytesRead;
        while ((bytesRead = fis.read(dataBytes)) != -1) {
            md.update(dataBytes, 0, bytesRead);
        }

        byte[] mdBytes = md.digest();

        StringBuilder sb = new StringBuilder();
        for (byte mdByte : mdBytes) {
            sb.append(Integer.toString((mdByte & 0xff) + 0x100, 16).substring(1));
        }
        return sb.toString();
    }

    public static String calculateSHA1(File file) throws NoSuchAlgorithmException, IOException {
        InputStream inputStream = new FileInputStream(file);
        return calculateSHA1(inputStream);
    }

    public static String calculateSHA1(InputStream inputStream) throws NoSuchAlgorithmException, IOException {
        MessageDigest digest = MessageDigest.getInstance("SHA-1");
        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            digest.update(buffer, 0, bytesRead);
        }
        byte[] hashBytes = digest.digest();
        return bytesToHex(hashBytes, true);
    }

    /**
     * 计算字节数组的 SHA256 哈希值
     *
     * @param data 字节数组
     * @return SHA256 哈希值（小写十六进制字符串）
     */
    public static String sha256(byte[] data) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hashBytes = digest.digest(data);
            return bytesToHex(hashBytes);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("SHA-256 algorithm not found", e);
        }
    }

    public static String calculateSHA256(File file) throws NoSuchAlgorithmException, IOException {
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        try (InputStream inputStream = new FileInputStream(file)) {
            byte[] buffer = new byte[4096];
            int bytesRead;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                digest.update(buffer, 0, bytesRead);
            }
        }
        byte[] hashBytes = digest.digest();
        return bytesToHex(hashBytes);
    }

    private static String bytesToHex(byte[] bytes) {
        StringBuilder hexString = new StringBuilder();
        for (byte b : bytes) {
            String hex = String.format("%02x", b & 0xFF);
            /*大写*/
//            String hex = String.format("%02X", b & 0xFF);
            hexString.append(hex);
        }
        return hexString.toString();
    }

    private static String bytesToHex(byte[] bytes, boolean upcase) {
        String format = upcase ? "%02X" : "%02x";
        StringBuilder hexString = new StringBuilder();
        for (byte b : bytes) {
            String hex = String.format(format, b & 0xFF);
            hexString.append(hex);
        }
        return hexString.toString();
    }
}