douyin/service/DouyinLiveStatusClient.cs

using System.Net;
using dy.net.model.dto;
using dy.net.utils;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace dy.net.service
{
    public interface IDouyinLiveStatusClient
    {
        Task<DouyinLiveStatusProbe> ProbeAsync(
            string secUid,
            string cookie,
            CancellationToken cancellationToken = default);
    }

    public sealed class DouyinLiveStatusRequestException : InvalidOperationException
    {
        public DouyinLiveStatusRequestException(
            string message,
            HttpStatusCode? statusCode = null,
            bool requiresAccountCooldown = false,
            Exception innerException = null)
            : base(message, innerException)
        {
            StatusCode = statusCode;
            RequiresAccountCooldown = requiresAccountCooldown;
        }

        public HttpStatusCode? StatusCode { get; }
        public bool RequiresAccountCooldown { get; }
    }

    public sealed class DouyinLiveStatusClient : IDouyinLiveStatusClient
    {
        private const string ProfilePath = "/aweme/v1/web/user/profile/other/";
        private readonly IHttpClientFactory _clientFactory;
        private readonly DouyinABogusSigner _signer = new();

        public DouyinLiveStatusClient(IHttpClientFactory clientFactory) => _clientFactory = clientFactory;

        public async Task<DouyinLiveStatusProbe> ProbeAsync(
            string secUid,
            string cookie,
            CancellationToken cancellationToken = default)
        {
            if (string.IsNullOrWhiteSpace(secUid))
                throw new InvalidOperationException("博主 SecUid 为空，无法检查直播状态");
            if (string.IsNullOrWhiteSpace(cookie))
                throw new InvalidOperationException("授权 Cookie 为空，无法检查直播状态");

            var parameters = BuildParameters(secUid.Trim(), cookie);
            var unsignedQuery = BuildQueryString(parameters);
            var requestUri = ProfilePath + "?" + unsignedQuery + "&a_bogus=" + Encode(_signer.Sign(unsignedQuery));
            using var request = new HttpRequestMessage(HttpMethod.Get, requestUri);
            request.Headers.Referrer = new Uri("https://www.douyin.com/user/" + Encode(secUid.Trim()));
            request.Headers.TryAddWithoutValidation("Accept", "application/json, text/plain, */*");
            request.Headers.TryAddWithoutValidation("Cookie", cookie);

            var client = _clientFactory.CreateClient(DouyinRequestParamManager.DY_HTTP_CLIENT);
            try
            {
                using var response = await client.SendAsync(
                    request,
                    HttpCompletionOption.ResponseHeadersRead,
                    cancellationToken);
                if (!response.IsSuccessStatusCode)
                {
                    var shouldCooldown = response.StatusCode is HttpStatusCode.Forbidden
                        or HttpStatusCode.TooManyRequests
                        or HttpStatusCode.Unauthorized;
                    throw new DouyinLiveStatusRequestException(
                        $"抖音直播状态请求失败（HTTP {(int)response.StatusCode}）",
                        response.StatusCode,
                        shouldCooldown);
                }

                var content = await response.Content.ReadAsStringAsync(cancellationToken);
                UserProfileResponse payload;
                try
                {
                    payload = JsonConvert.DeserializeObject<UserProfileResponse>(content);
                }
                catch (JsonException ex)
                {
                    throw new DouyinLiveStatusRequestException(
                        "抖音返回了无法识别的直播状态响应，可能需要验证授权",
                        requiresAccountCooldown: true,
                        innerException: ex);
                }

                if (payload?.User == null)
                    throw new DouyinLiveStatusRequestException(
                        "抖音没有返回博主资料，可能需要验证授权",
                        requiresAccountCooldown: true);
                if (payload.StatusCode != 0)
                    throw new DouyinLiveStatusRequestException(
                        $"抖音拒绝了直播状态查询（状态码 {payload.StatusCode}）",
                        requiresAccountCooldown: true);

                return DouyinLiveStatusParser.Parse(
                    payload.User.LiveStatus,
                    payload.User.RoomId,
                    payload.User.RoomIdStr,
                    payload.User.RoomData);
            }
            catch (DouyinLiveStatusRequestException)
            {
                throw;
            }
            catch (HttpRequestException ex)
            {
                throw new DouyinLiveStatusRequestException("抖音直播状态网络请求失败，请稍后重试", innerException: ex);
            }
            catch (OperationCanceledException ex) when (!cancellationToken.IsCancellationRequested)
            {
                throw new DouyinLiveStatusRequestException("抖音直播状态查询超时，请稍后重试", innerException: ex);
            }
        }

        private static List<KeyValuePair<string, string>> BuildParameters(string secUid, string cookie)
        {
            var cookies = ParseCookie(cookie);
            return new List<KeyValuePair<string, string>>
            {
                new("device_platform", "webapp"),
                new("aid", "6383"),
                new("channel", "channel_pc_web"),
                new("update_version_code", "170400"),
                new("pc_client_type", "1"),
                new("pc_libra_divert", "Windows"),
                new("support_h265", "1"),
                new("support_dash", "1"),
                new("version_code", "170400"),
                new("version_name", "17.4.0"),
                new("cookie_enabled", "true"),
                new("screen_width", "1536"),
                new("screen_height", "864"),
                new("browser_language", "zh-CN"),
                new("browser_platform", "Win32"),
                new("browser_name", "Chrome"),
                new("browser_version", "119.0.0.0"),
                new("browser_online", "true"),
                new("engine_name", "Blink"),
                new("engine_version", "119.0.0.0"),
                new("os_name", "Windows"),
                new("os_version", "10"),
                new("cpu_core_num", "16"),
                new("device_memory", "8"),
                new("platform", "PC"),
                new("downlink", "10"),
                new("effective_type", "4g"),
                new("round_trip_time", "200"),
                new("uifid", CookieValue(cookies, "UIFID", "UIFID_TEMP")),
                new("msToken", CookieValue(cookies, "msToken")),
                new("sec_user_id", secUid),
                new("publish_video_strategy_type", "2"),
                new("personal_center_strategy", "1")
            };
        }

        private static Dictionary<string, string> ParseCookie(string cookie)
        {
            var values = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
            foreach (var part in (cookie ?? string.Empty).Split(';', StringSplitOptions.RemoveEmptyEntries))
            {
                var separator = part.IndexOf('=');
                if (separator <= 0) continue;
                values[part[..separator].Trim()] = part[(separator + 1)..].Trim();
            }
            return values;
        }

        private static string CookieValue(Dictionary<string, string> cookies, params string[] names)
        {
            foreach (var name in names)
                if (cookies.TryGetValue(name, out var value)) return value;
            return string.Empty;
        }

        private static string BuildQueryString(IEnumerable<KeyValuePair<string, string>> parameters) =>
            string.Join("&", parameters.Select(x => Encode(x.Key) + "=" + Encode(x.Value ?? string.Empty)));

        private static string Encode(string value) => Uri.EscapeDataString(value ?? string.Empty);

        private sealed class UserProfileResponse
        {
            [JsonProperty("status_code")]
            public int StatusCode { get; set; }

            [JsonProperty("user")]
            public UserProfile User { get; set; }
        }

        private sealed class UserProfile
        {
            [JsonProperty("live_status")]
            public int? LiveStatus { get; set; }

            [JsonProperty("room_id")]
            public string RoomId { get; set; }

            [JsonProperty("room_id_str")]
            public string RoomIdStr { get; set; }

            [JsonProperty("room_data")]
            public JToken RoomData { get; set; }
        }
    }
}