import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.Random;
import java.io.OutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import org.json.JSONObject;

public class Demo {

    // 加密
    public static String aesEncrypt(String plainText, String hexKey) throws Exception {
        byte[] keyBytes = hexStringToByteArray(hexKey);
        byte[] iv = new byte[16];
        new SecureRandom().nextBytes(iv);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivSpec);

        byte[] encrypted = cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8));

        // 拼接 IV 和密文
        byte[] encryptedData = new byte[iv.length + encrypted.length];
        System.arraycopy(iv, 0, encryptedData, 0, iv.length);
        System.arraycopy(encrypted, 0, encryptedData, iv.length, encrypted.length);

        return Base64.getEncoder().encodeToString(encryptedData);
    }

    // 解密
    public static String aesDecrypt(String encryptedText, String hexKey) throws Exception {
        byte[] encryptedBytes = Base64.getDecoder().decode(encryptedText);
        byte[] keyBytes = hexStringToByteArray(hexKey);

        byte[] iv = new byte[16];
        System.arraycopy(encryptedBytes, 0, iv, 0, 16);

        byte[] encryptedData = new byte[encryptedBytes.length - 16];
        System.arraycopy(encryptedBytes, 16, encryptedData, 0, encryptedData.length);

        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);

        byte[] decrypted = cipher.doFinal(encryptedData);
        return new String(decrypted, StandardCharsets.UTF_8);
    }

    // Helper 方法，将 16 进制字符串转为字节数组
    public static byte[] hexStringToByteArray(String s) {
        int len = s.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4) + Character.digit(s.charAt(i + 1), 16));
        }
        return data;
    }

    // 发送 HTTP POST 请求
    public static String sendPostRequest(String urlString, String data, String accessId) throws Exception {
        URL url = new URL(urlString);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type", "application/json");
        connection.setRequestProperty("Access-Id", accessId);
        connection.setDoOutput(true);

        // 构造请求体
        String jsonInputString = "{\"data\":\"" + data + "\"}";
        try (OutputStream os = connection.getOutputStream()) {
            byte[] input = jsonInputString.getBytes("utf-8");
            os.write(input, 0, input.length);
        }

        // 读取响应
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream(), "utf-8"));
        StringBuilder response = new StringBuilder();
        String responseLine;
        while ((responseLine = br.readLine()) != null) {
            response.append(responseLine.trim());
        }

        return response.toString();
    }

    public static void main(String[] args) {
        try {
            // 设置 URL、密钥和请求参数
            String url = "https://api.tianyuanapi.com/api/v1/IVYZ5733";
            String accessId = "XXXXXXXXXXXXX";
            String key = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";

            // 请求参数
            JSONObject requestParams = new JSONObject();
            requestParams.put("name", "李四");
            requestParams.put("id_card", "110101199003076534");

            // 将请求参数转为 JSON 字符串
            String jsonStr = requestParams.toString();

            // 加密请求数据
            String encryptedData = aesEncrypt(jsonStr, key);

            // 发送 HTTP POST 请求并获取响应
            String response = sendPostRequest(url, encryptedData, accessId);

            // 解析响应数据
            JSONObject responseData = new JSONObject(response);
            String encryptedResponseData = responseData.optString("data");

            // 解密返回的加密数据
            if (encryptedResponseData != null) {
                String decryptedResponseData = aesDecrypt(encryptedResponseData, key);
                System.out.println("Decrypted Response Data: " + decryptedResponseData);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}