DanMuRead/BarrageGrab/Utility/BiliApiHelper.cs

using System;
using System.Net.Http;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using BarrageGrab.Modles;
using Newtonsoft.Json.Linq;

namespace BarrageGrab
{
    /// <summary>
    /// B站直播API帮助类
    /// </summary>
    internal class BiliApiHelper
    {
        private const string UA = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0";

        /// <summary>
        /// 通过B站官方API获取房间信息 (推荐方式,稳定可靠)
        /// 流程: get_info API 获取房间基本信息 -> Master/info API 获取主播昵称/头像
        /// </summary>
        public static async Task<BiliRoomInfo> GetRoomInfoByApi(string webRoomId, string cookie = null)
        {
            if (string.IsNullOrWhiteSpace(webRoomId)) return null;

            var client = CreateHttpClient(cookie);

            try
            {
                // 1. 获取房间信息 (get_info 支持短ID/长ID自动转换)
                string roomInfoUrl = $"https://api.live.bilibili.com/room/v1/Room/get_info?room_id={webRoomId}";
                var roomResp = await client.GetStringAsync(roomInfoUrl);
                var roomJson = JObject.Parse(roomResp);

                if (roomJson["code"]?.Value<int>() != 0)
                {
                    Logger.LogWarn($"B站 get_info API 返回错误: {roomJson["message"]?.Value<string>()}");
                    return null;
                }

                var data = roomJson["data"];
                var info = new BiliRoomInfo
                {
                    WebRoomId = webRoomId,
                    RoomId = data["room_id"]?.Value<long>().ToString() ?? webRoomId,
                    ShortId = data["short_id"]?.Value<long>().ToString() ?? "0",
                    Uid = data["uid"]?.Value<long>().ToString() ?? "",
                    Title = data["title"]?.Value<string>() ?? "",
                    IsLive = (data["live_status"]?.Value<int>() ?? 0) == 1,
                    Online = data["online"]?.Value<long>() ?? 0,
                    AreaName = data["area_name"]?.Value<string>() ?? "",
                    ParentAreaName = data["parent_area_name"]?.Value<string>() ?? "",
                    CoverUrl = data["user_cover"]?.Value<string>()
                                ?? data["keyframe"]?.Value<string>()
                                ?? ""
                };

                // 2. 获取主播昵称和头像
                if (!string.IsNullOrWhiteSpace(info.Uid))
                {
                    try
                    {
                        string masterUrl = $"https://api.live.bilibili.com/live_user/v1/Master/info?uid={info.Uid}";
                        var masterResp = await client.GetStringAsync(masterUrl);
                        var masterJson = JObject.Parse(masterResp);

                        if (masterJson["code"]?.Value<int>() == 0)
                        {
                            var masterData = masterJson["data"];
                            info.Nickname = masterData["info"]?["uname"]?.Value<string>() ?? "";
                            info.HeadUrl = masterData["info"]?["face"]?.Value<string>() ?? "";
                        }
                    }
                    catch (Exception ex)
                    {
                        Logger.LogWarn($"获取B站主播信息失败: {ex.Message}");
                    }
                }

                if (string.IsNullOrWhiteSpace(info.Nickname))
                {
                    info.Nickname = $"B站用户{info.Uid}";
                }

                Logger.LogInfo($"B站API获取房间信息成功: WebRoomId={webRoomId}, RoomId={info.RoomId}, Uname={info.Nickname}, Online={info.Online}, IsLive={info.IsLive}");
                return info;
            }
            catch (Exception ex)
            {
                Logger.LogError(ex, $"B站API获取房间信息失败: {ex.Message}");
                return null;
            }
        }

        /// <summary>
        /// 从B站直播间页面HTML中解析房间信息 (备用方案)
        /// 注意: B站前端改版后页面可能不再注入 __INITIAL_STATE__, 此方法可能失效
        /// </summary>
        public static BiliRoomInfo ParseRoomInfoFromHtml(string html, string webRoomId)
        {
            var info = new BiliRoomInfo { WebRoomId = webRoomId };
            if (string.IsNullOrWhiteSpace(html)) return info;

            try
            {
                // 用括号配对算法可靠提取 __INITIAL_STATE__ 的 JSON
                string jsonStr = ExtractJsonObject(html, "__INITIAL_STATE__");
                if (string.IsNullOrWhiteSpace(jsonStr))
                {
                    // B站改版后可能不再注入 __INITIAL_STATE__, 返回空对象由调用方走API
                    return info;
                }

                JObject root;
                try
                {
                    root = JObject.Parse(jsonStr);
                }
                catch (Exception ex)
                {
                    Logger.LogWarn($"B站 __INITIAL_STATE__ JSON 解析失败: {ex.Message}");
                    return info;
                }

                var roomInfoNode = root["roomInfo"]?["roomInfo"];
                var anchorInfoNode = root["roomInfo"]?["anchorInfo"];

                if (roomInfoNode != null)
                {
                    info.RoomId = TokenToString(roomInfoNode["room_id"], webRoomId);
                    info.ShortId = TokenToString(roomInfoNode["short_id"], "0");
                    info.Uid = TokenToString(roomInfoNode["uid"], "");
                    info.Title = roomInfoNode["title"]?.Value<string>() ?? "";
                    info.IsLive = (roomInfoNode["live_id"]?.Value<long>() ?? 0) != 0;
                    info.Online = roomInfoNode["online"]?.Value<long>() ?? 0;
                    info.AreaName = roomInfoNode["area_name"]?.Value<string>() ?? "";
                    info.ParentAreaName = roomInfoNode["parent_area_name"]?.Value<string>() ?? "";
                    info.CoverUrl = roomInfoNode["cover"]?.Value<string>()
                                    ?? roomInfoNode["keyframe"]?.Value<string>()
                                    ?? "";
                }

                if (anchorInfoNode != null)
                {
                    var baseInfo = anchorInfoNode["base_info"];
                    info.Nickname = baseInfo?["uname"]?.Value<string>()
                                    ?? anchorInfoNode["uname"]?.Value<string>()
                                    ?? "";
                    info.HeadUrl = baseInfo?["face"]?.Value<string>()
                                    ?? anchorInfoNode["face"]?.Value<string>()
                                    ?? "";

                    var relationInfo = anchorInfoNode["relation_info"];
                    if (relationInfo != null)
                    {
                        info.Attention = relationInfo["attribute"]?.Value<int>() ?? 0;
                    }
                }

                Logger.LogInfo($"B站HTML解析房间成功: WebRoomId={webRoomId}, RoomId={info.RoomId}, Uname={info.Nickname}");
            }
            catch (Exception ex)
            {
                Logger.LogWarn($"解析B站页面房间信息时出错: {ex.Message}");
            }

            return info;
        }

        /// <summary>
        /// 从HTML中提取 __INITIAL_STATE__ 后的完整JSON对象 (括号配对算法)
        /// 不受 &lt; 字符或 ;(function 等干扰, 比正则更可靠
        /// </summary>
        private static string ExtractJsonObject(string html, string marker)
        {
            int idx = html.IndexOf(marker);
            if (idx < 0) return null;

            // 找到 = 后面的第一个 {
            int eqIdx = html.IndexOf('=', idx);
            if (eqIdx < 0) return null;

            int braceIdx = html.IndexOf('{', eqIdx);
            if (braceIdx < 0) return null;

            // 逐字符扫描计算 { } 嵌套层级, 同时处理字符串和转义
            int depth = 0;
            bool inString = false;
            bool escape = false;

            for (int i = braceIdx; i < html.Length; i++)
            {
                char c = html[i];

                if (escape) { escape = false; continue; }
                if (c == '\\') { escape = true; continue; }
                if (c == '"') { inString = !inString; continue; }
                if (inString) continue;

                if (c == '{') depth++;
                else if (c == '}')
                {
                    depth--;
                    if (depth == 0)
                    {
                        return html.Substring(braceIdx, i - braceIdx + 1);
                    }
                }
            }

            return null;
        }

        /// <summary>JSON token 转字符串 (兼容整数/字符串类型)</summary>
        private static string TokenToString(JToken token, string defaultValue)
        {
            if (token == null) return defaultValue;
            return token.Type == JTokenType.Integer
                ? token.Value<long>().ToString()
                : token.Value<string>() ?? defaultValue;
        }

        private static HttpClient CreateHttpClient(string cookie)
        {
            var client = new HttpClient();
            client.DefaultRequestHeaders.Add("User-Agent", UA);
            client.DefaultRequestHeaders.Add("Accept", "application/json, text/plain, */*");
            client.DefaultRequestHeaders.Add("Accept-Language", "zh-CN,zh;q=0.9");
            client.DefaultRequestHeaders.Add("Referer", "https://live.bilibili.com/");
            if (!string.IsNullOrWhiteSpace(cookie))
            {
                client.DefaultRequestHeaders.Add("Cookie", cookie);
            }
            return client;
        }
    }

    /// <summary>
    /// B站房间信息
    /// </summary>
    public class BiliRoomInfo
    {
        /// <summary>用户访问的房间号 (URL中的ID, 可能是短ID或真实room_id)</summary>
        public string WebRoomId { get; set; }
        /// <summary>真实的房间长ID</summary>
        public string RoomId { get; set; }
        /// <summary>短ID (无短ID时为"0")</summary>
        public string ShortId { get; set; }
        /// <summary>主播UID</summary>
        public string Uid { get; set; }
        /// <summary>直播间标题</summary>
        public string Title { get; set; }
        /// <summary>主播昵称</summary>
        public string Nickname { get; set; }
        /// <summary>主播头像</summary>
        public string HeadUrl { get; set; }
        /// <summary>直播间封面</summary>
        public string CoverUrl { get; set; }
        /// <summary>是否直播中</summary>
        public bool IsLive { get; set; }
        /// <summary>在线人数</summary>
        public long Online { get; set; }
        /// <summary>子分区名</summary>
        public string AreaName { get; set; }
        /// <summary>父分区名</summary>
        public string ParentAreaName { get; set; }
        /// <summary>关注状态 (0未关注 2已关注 6已互关)</summary>
        public int Attention { get; set; }
        /// <summary>直播间地址</summary>
        public string LiveUrl { get; set; }
    }
}