import cn.hutool.core.map.MapUtil;
import cn.hutool.crypto.digest.MD5;
import cn.hutool.http.Header;
import cn.hutool.http.HttpRequest;
import cn.hutool.json.JSONUtil;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Map;
import java.util.Objects;
import java.util.UUID;

/**
 * 

 * OpenApi 调用方示例
 * 
 */
public class OpenApiDemo {

    public static void main(String[] args) throws Exception {
        OpenApiDemo openApiDemo = new OpenApiDemo();
        String response = openApiDemo.callOpenApiTest();
        System.out.println("调用OpenApi结果：" + response);
    }

    /**
     * 调用OpenAPi主函数
     *
     * @return Response Body
     * @throws Exception 构造请求密文抛出的异常
     */
    public String callOpenApiTest() throws Exception {
        long timeStamp = System.currentTimeMillis();
        // 1. kctrace生成： 随机的32位字符串，每次请求的kctrace值不重复
        String kctrace = UUID.randomUUID().toString().substring(0, 32);

        // 2. 请求参数 加密
        Map param = MapUtil.builder("key", (Object) "value").build();
        String content = OpenApiDemo.encryptAES(JSONUtil.toJsonStr(param), AppInfoConfig.appSecret);

        // 3. sign生成
        String signOriginStr = String.format("apiPath=%s&appId=%s&content=%s&kctrace=%s&secret=%s×tamp=%s",
                this.apiUrlDemo, AppInfoConfig.appId, content, kctrace, AppInfoConfig.appSecret, timeStamp);
        // MD5 工具使用了Hutool库提供的
        String sign = MD5.create().digestHex(signOriginStr);

        String queryParam = String.format("?kctrace=%s&appId=%s&secretId=%s×tamp=%s&sign=%s",
                kctrace, AppInfoConfig.appId, AppInfoConfig.secretId, Objects.toString(timeStamp), sign);                                                                                          // 4. 构造请求 并发起调用，这里用了Hutool 库的 Http工具
        String url = String.format("%s://%s:%s%s%s", this.protocol, this.host, this.port, this.apiUrlDemo, queryParam);
        String responseBody = HttpRequest.post(url).header(Header.USER_AGENT, "Hutool http")//头信息，多个头信息多次调用此方法即可
                .header(Header.ACCEPT, "application/json;charset=UTF-8")//头信息
                .header(Header.CONTENT_TYPE, "application/x-www-form-urlencoded")//头信息
                .form("content", content)
                .execute()
                .body();

        System.out.println(responseBody);
        return responseBody;
    }

    /**
     * 获取请求参数密文
     *
     * @param cleartext    原文
     * @param dataPassword 秘钥
     * @return 密文
     */
    private static String encryptAES(String cleartext, String dataPassword) throws Exception {
        final byte[] KEY_VI = new byte[]{1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8};
        IvParameterSpec zeroIv = new IvParameterSpec(KEY_VI);
        SecretKeySpec key = new SecretKeySpec(dataPassword.getBytes("UTF-8"), "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(1, key, zeroIv);
        byte[] encryptedData = cipher.doFinal(cleartext.getBytes("UTF-8"));
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < encryptedData.length; ++i) {
            String hex = Integer.toHexString(encryptedData[i] & 255);
            if (hex.length() == 1) {
                hex = '0' + hex;
            }
            sb.append(hex.toUpperCase());
        }
        return new String(sb.toString());
    }

    /**
     * APP 相关配置
     */
    private static class AppInfoConfig {
        /**
         * 应用ID
         */
        private static String appId = "250409105367890";
        /**
         * 应用秘钥
         */
        private static String appSecret = "3d210f51d9bb2db86f56091b5e883796";
        /**
         * 秘钥 ID
         */
        private static String secretId = "22";
    }
}