using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json;

public class HttpHelper
{
	private static readonly HttpClient client = new HttpClient();

	/// <summary>
	/// 判断是否为 URL
	/// </summary>
	public static bool IsUrl(string url)
	{
		if (string.IsNullOrEmpty(url))
			return false;

		url = url.ToLower();
		return url.StartsWith("http://") || url.StartsWith("https://");
	}

	/// <summary>
	/// 异步 GET 请求
	/// </summary>
	public static async Task<HttpResponse> HttpGetAsync(string url, int timeout = 10 * 1000)
	{
		try
		{
			// 设置超时时间
			client.Timeout = TimeSpan.FromMilliseconds(timeout);

			HttpResponseMessage response = await client.GetAsync(url);
			response.EnsureSuccessStatusCode();

			string content = await response.Content.ReadAsStringAsync();
			return new HttpResponse(response.StatusCode, content);
		}
		catch (HttpRequestException ex)
		{
			Console.WriteLine($"GET Request Error: {ex.Message}");
			return new HttpResponse(HttpStatusCode.BadRequest, $"Error: {ex.Message}");
		}
		catch (TaskCanceledException ex)
		{
			Console.WriteLine($"Request Timeout or Cancelled: {ex.Message}");
			return new HttpResponse(HttpStatusCode.RequestTimeout, "Request timed out.");
		}
		catch (Exception ex)
		{
			Console.WriteLine($"Unexpected Error: {ex.Message}");
			return new HttpResponse(HttpStatusCode.InternalServerError, $"Unexpected error: {ex.Message}");
		}
	}

	/// <summary>
	/// 异步 POST 请求
	/// </summary>
	public static async Task<HttpResponse> HttpPostAsync<T>(string postUrl, T postData, string contentType = "application/json", int timeout = 10 * 1000)
	{
		try
		{
			// 设置超时时间
			client.Timeout = TimeSpan.FromMilliseconds(timeout);

			string jsonContent = JsonConvert.SerializeObject(postData);
			var content = new StringContent(jsonContent, Encoding.UTF8, contentType);

			HttpResponseMessage response = await client.PostAsync(postUrl, content);
			response.EnsureSuccessStatusCode();

			string responseBody = await response.Content.ReadAsStringAsync();
			return new HttpResponse(response.StatusCode, responseBody);
		}
		catch (HttpRequestException ex)
		{
			Console.WriteLine($"POST Request Error: {ex.Message}");
			return new HttpResponse(HttpStatusCode.BadRequest, $"Error: {ex.Message}");
		}
		catch (TaskCanceledException ex)
		{
			Console.WriteLine($"Request Timeout or Cancelled: {ex.Message}");
			return new HttpResponse(HttpStatusCode.RequestTimeout, "Request timed out.");
		}
		catch (Exception ex)
		{
			Console.WriteLine($"Unexpected Error: {ex.Message}");
			return new HttpResponse(HttpStatusCode.InternalServerError, $"Unexpected error: {ex.Message}");
		}
	}

	/// <summary>
	/// 根据传入的数据，得到相应页面数据（适用于复杂的 HTTP 请求）
	/// </summary>
	public static async Task<HttpResponse> GetHttpRequestDataAsync(HttpItem httpItem)
	{
		using (var requestMessage = new HttpRequestMessage())
		{
			try
			{
				// 设置请求方法
				requestMessage.Method = new HttpMethod(httpItem.Method);
				requestMessage.RequestUri = new Uri(GetUrl(httpItem.URL));

				// 设置请求头
				foreach (var header in httpItem.Headers ?? Array.Empty<KeyValuePair<string, string>>())
				{
					requestMessage.Headers.Add(header.Key, header.Value);
				}

				// 设置内容类型
				if (!string.IsNullOrEmpty(httpItem.ContentType))
				{
					requestMessage.Content = new StringContent(httpItem.Postdata!, Encoding.UTF8, httpItem.ContentType);
				}

				// 设置 Cookie
				if (!string.IsNullOrEmpty(httpItem.Cookie))
				{
					requestMessage.Headers.Add("Cookie", httpItem.Cookie);
				}

				// 发送请求并获取响应
				HttpResponseMessage response = await client.SendAsync(requestMessage);
				response.EnsureSuccessStatusCode();

				string content = await response.Content.ReadAsStringAsync();
				return new HttpResponse(response.StatusCode, content);
			}
			catch (Exception ex)
			{
				Console.WriteLine($"Request Error: {ex.Message}");
				return new HttpResponse(HttpStatusCode.InternalServerError, $"Error: {ex.Message}");
			}
		}
	}

	/// <summary>
	/// 确保 URL 包含协议前缀
	/// </summary>
	private static string GetUrl(string url)
	{
		if (!(url.Contains("http://") || url.Contains("https://")))
		{
			url = "http://" + url;
		}
		return url;
	}
}

/// <summary>
/// HTTP 响应结果类
/// </summary>
public class HttpResponse
{
	public HttpStatusCode StatusCode { get; set; }
	public string Content { get; set; }

	public HttpResponse(HttpStatusCode statusCode, string content)
	{
		StatusCode = statusCode;
		Content = content;
	}
}

/// <summary>
/// HTTP 请求项类
/// </summary>
public class HttpItem
{
	public string URL { get; set; } = "";
	public string Method { get; set; } = "GET";
	public int Timeout { get; set; } = 10000;
	public string ContentType { get; set; } = "application/json";
	public string? Postdata { get; set; }
	public string? Cookie { get; set; }
	public KeyValuePair<string, string>[] Headers { get; set; }=new KeyValuePair<string, string>[0];
}