using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

namespace BetterGenshinImpact.Helpers.Http;

public class ProxySpeedTester
{
    private static readonly HttpClient _httpClient = new() { Timeout = TimeSpan.FromSeconds(5) };

    public static readonly List<string> ProxyUrls =
    [
        "{0}",
        "https://mirror.ghproxy.com/{0}",
        "https://hub.gitmirror.com/{0}",
        "https://ghproxy.cc/{0}",
        "https://www.ghproxy.cc/{0}",
        "https://ghproxy.cn/{0}",
        "https://ghproxy.net/{0}"
    ];

    /// <summary>
    /// 获得最快的代理地址
    /// </summary>
    /// <param name="target"></param>
    /// <returns>最快的代理地址,结果</returns>
    public static async Task<(string, string)> GetFastestProxyAsync(string target)
    {
        return await GetFastestProxyAsync(ProxyUrls, target);
    }

    public static async Task<(string, string)> GetFastestProxyAsync(List<string> proxyAddresses, string target)
    {
        var tasks = new List<Task<(string, string, bool)>>(); // 修改为包含成功标志的元组
        var cts = new CancellationTokenSource();

        foreach (var proxy in proxyAddresses)
        {
            // 如果目标地址为空且代理地址为默认地址，则跳过
            if (string.IsNullOrEmpty(target) && proxy == "{0}")
            {
                continue;
            }

            tasks.Add(TestProxyAsync(proxy, target, cts.Token));
        }

        while (tasks.Count > 0)
        {
            var firstCompletedTask = await Task.WhenAny(tasks);
            tasks.Remove(firstCompletedTask);

            var result = await firstCompletedTask;
            if (result.Item3) // 检查是否成功
            {
                await cts.CancelAsync(); // 取消所有其他请求
                return (result.Item1, result.Item2); // 返回第一个成功的代理地址
            }
        }

        return (string.Empty, string.Empty); // 如果没有成功的结果，返回空
    }

    private static async Task<(string, string, bool)> TestProxyAsync(string proxyAddress, string target, CancellationToken cancellationToken)
    {
        try
        {
            // 模拟代理测试请求
            var response = await _httpClient.GetAsync(string.Format(proxyAddress, target), cancellationToken);
            response.EnsureSuccessStatusCode();
            return (proxyAddress, await response.Content.ReadAsStringAsync(cancellationToken), true);
        }
        catch (Exception e)
        {
            return (proxyAddress, e.Message, false);
        }
    }
}