using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;

public class HttpClientHelper
{
    private readonly HttpClient _httpClient;

    public HttpClientHelper()
    {
        _httpClient = new HttpClient();
        // 设置一些默认的请求头
        _httpClient.DefaultRequestHeaders.Add("User-Agent", "C#-HttpClientHelper");
    }

    // 发送 GET 请求
    public async Task<string> GetAsync(string url)
    {
        try
        {
            HttpResponseMessage response = await _httpClient.GetAsync(url);
            response.EnsureSuccessStatusCode(); // 如果响应状态码不是 2xx，会抛出异常
            return await response.Content.ReadAsStringAsync();
        }
        catch (Exception ex)
        {
            // 处理异常
            return $"Error: {ex.Message}";
        }
    }

    // 发送 POST 请求
    public async Task<string> PostAsync(string url, object data)
    {
        try
        {
            var jsonContent = JsonConvert.SerializeObject(data);
            var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

            HttpResponseMessage response = await _httpClient.PostAsync(url, content);
            response.EnsureSuccessStatusCode();
            return await response.Content.ReadAsStringAsync();
        }
        catch (Exception ex)
        {
            return $"Error: {ex.Message}";
        }
    }

    // 发送 PUT 请求
    public async Task<string> PutAsync(string url, object data)
    {
        try
        {
            var jsonContent = JsonConvert.SerializeObject(data);
            var content = new StringContent(jsonContent, Encoding.UTF8, "application/json");

            HttpResponseMessage response = await _httpClient.PutAsync(url, content);
            response.EnsureSuccessStatusCode();
            return await response.Content.ReadAsStringAsync();
        }
        catch (Exception ex)
        {
            return $"Error: {ex.Message}";
        }
    }

    // 发送 DELETE 请求
    public async Task<string> DeleteAsync(string url)
    {
        try
        {
            HttpResponseMessage response = await _httpClient.DeleteAsync(url);
            response.EnsureSuccessStatusCode();
            return await response.Content.ReadAsStringAsync();
        }
        catch (Exception ex)
        {
            return $"Error: {ex.Message}";
        }
    }
}