package org.example;

/**
 * packageName com.example.demo
 *
 * @author congtiexin
 * @date 2025/6/3
 * @description TODO
 */

import com.google.gson.Gson;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class HttpUtils {

    private static final Gson gson = new Gson();

    /**
     * 发送 POST 请求并返回 JSON 响应
     *
     * @param url      请求地址
     * @param request  请求对象（Java Bean 或 Map）
     * @return         响应内容（Map 或 自定义对象）
     */
    public static <T> T postJson(String url, Object request, Class<T> responseType) throws Exception {
        HttpURLConnection connection = null;
        try {
            // 初始化连接
            connection = (HttpURLConnection) new URL(url).openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
            connection.setRequestProperty("Accept", "application/json");
            connection.setDoOutput(true);

            // 序列化请求体
            String jsonInput = gson.toJson(request);
            try (OutputStream os = connection.getOutputStream()) {
                os.write(jsonInput.getBytes("UTF-8"));
                os.flush();
            }

            // 处理响应
            int responseCode = connection.getResponseCode();
            if (responseCode != HttpURLConnection.HTTP_OK) {
                throw new RuntimeException("请求失败，状态码: " + responseCode);
            }

            StringBuilder response = new StringBuilder();
            try (BufferedReader br = new BufferedReader(
                    new InputStreamReader(connection.getInputStream(), "UTF-8"))) {
                String line;
                while ((line = br.readLine()) != null) {
                    response.append(line);
                }
            }

            // 反序列化响应
            return gson.fromJson(response.toString(), responseType);
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }

    /**
     * 快速发送 JSON POST 请求并返回原始字符串响应
     */
    public static String postJson(String url, String jsonBody) throws Exception {
        HttpURLConnection connection = null;
        try {
            connection = (HttpURLConnection) new URL(url).openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
            connection.setDoOutput(true);

            try (OutputStream os = connection.getOutputStream()) {
                byte[] input = jsonBody.getBytes("UTF-8");
                os.write(input, 0, input.length);
                os.flush();
            }

            int responseCode = connection.getResponseCode();
            if (responseCode != HttpURLConnection.HTTP_OK) {
                throw new RuntimeException("请求失败，状态码: " + responseCode);
            }

            StringBuilder response = new StringBuilder();
            try (BufferedReader br = new BufferedReader(
                    new InputStreamReader(connection.getInputStream(), "UTF-8"))) {
                String line;
                while ((line = br.readLine()) != null) {
                    response.append(line);
                }
            }

            return response.toString();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }
}