BililiveRecorder/BililiveRecorder.Core/BililiveAPI.cs

using Newtonsoft.Json.Linq;
using NLog;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;

namespace BililiveRecorder.Core
{
    internal static class BililiveAPI
    {
        private static readonly Logger logger = LogManager.GetCurrentClassLogger();
        private static readonly Random random = new Random();
        private static readonly HttpClient httpclient;

        static BililiveAPI()
        {
            httpclient = new HttpClient { Timeout = TimeSpan.FromSeconds(5) };
            httpclient.DefaultRequestHeaders.Add("Accept", "application/json, text/javascript, */*; q=0.01");
            httpclient.DefaultRequestHeaders.Add("Referer", "https://live.bilibili.com/");
            httpclient.DefaultRequestHeaders.Add("User-Agent", Utils.UserAgent);
        }


        /// <summary>
        /// 下载json并解析
        /// </summary>
        /// <param name="url">下载路径</param>
        /// <returns>数据</returns>
        /// <exception cref="ArgumentNullException"/>
        /// <exception cref="WebException"/>
        public static async Task<JObject> HttpGetJsonAsync(string url)
        {
            var s = await httpclient.GetStringAsync(url);
            var j = JObject.Parse(s);
            return j;
        }

        /// <summary>
        /// 获取直播间播放地址
        /// </summary>
        /// <param name="roomid">原房间号</param>
        /// <returns>FLV播放地址</returns>
        /// <exception cref="WebException"/>
        /// <exception cref="Exception"/>
        public static async Task<string> GetPlayUrlAsync(int roomid)
        {
            string url = $@"https://api.live.bilibili.com/room/v1/Room/playUrl?cid={roomid}&quality=4&platform=web";
            if ((await HttpGetJsonAsync(url))?["data"]?["durl"] is JArray array)
            {
                List<string> urls = new List<string>();
                for (int i = 0; i < array.Count; i++)
                {
                    urls.Add(array[i]?["url"]?.ToObject<string>());
                }
                var distinct = urls.Distinct().ToArray();
                if (distinct.Length > 0)
                {
                    return distinct[random.Next(0, distinct.Count() - 1)];
                }
            }
            throw new Exception("没有直播播放地址");
        }

        /// <summary>
        /// 获取直播间信息
        /// </summary>
        /// <param name="roomid">房间号（允许短号）</param>
        /// <returns>直播间信息</returns>
        /// <exception cref="WebException"/>
        /// <exception cref="Exception"/>
        public static async Task<RoomInfo> GetRoomInfoAsync(int roomid)
        {
            try
            {
                var room = await HttpGetJsonAsync($@"https://api.live.bilibili.com/room/v1/Room/get_info?id={roomid}");
                if (room["code"].ToObject<int>() != 0)
                {
                    logger.Warn("不能获取 {roomid} 的信息1: {errormsg}", roomid, room["message"]?.ToObject<string>());
                    return null;
                }

                var user = await HttpGetJsonAsync($@"https://api.live.bilibili.com/live_user/v1/UserInfo/get_anchor_in_room?roomid={roomid}");
                if (user["code"].ToObject<int>() != 0)
                {
                    logger.Warn("不能获取 {roomid} 的信息2: {errormsg}", roomid, room["message"]?.ToObject<string>());
                    return null;
                }

                var i = new RoomInfo()
                {
                    ShortRoomId = room?["data"]?["short_id"]?.ToObject<int>() ?? throw new Exception("未获取到直播间信息"),
                    RoomId = room?["data"]?["room_id"]?.ToObject<int>() ?? throw new Exception("未获取到直播间信息"),
                    IsStreaming = 1 == (room?["data"]?["live_status"]?.ToObject<int>() ?? throw new Exception("未获取到直播间信息")),
                    UserName = user?["data"]?["info"]?["uname"]?.ToObject<string>() ?? throw new Exception("未获取到直播间信息"),
                };
                return i;
            }
            catch (Exception ex)
            {
                logger.Warn(ex, "获取直播间 {roomid} 的信息时出错", roomid);
                throw;
            }
        }
    }
}