Unity script example for YouTube Live Streaming

YtlClient.cs

using System.Collections;
using System.Collections.Generic;
using System;
using UnityEngine;
using UnityEngine.Networking;
using SimpleJSON;

namespace YouTubeLive {
  public class Chat {
    public class Msg {
      public string text;
      public string name;
      public string img;
    }
    public List<Msg> msgs = new List<Msg>();
    public string pageToken;
  }

  [Serializable]
  public class Access {
    [Header("YouTube")]
    public string id = "_video_uri";

    [Header("OAuth")]
    public string clientId = "_client_id";
    public string clientSecret = "_client_secret";

    [Header("Options")]
    public string redirectUri = "http://localhost:8080";
    public string grantType = "authorization_code";
    public string accessType = "offline";
    public string scope = "https://www.googleapis.com/auth/youtube.readonly";
    public string code = "";
    public string token = "";
  }

  public class YtlClient : MonoBehaviour {
    public Access access { set; get; }

    public string AuthUrl() {
      return "https://accounts.google.com/o/oauth2/v2/auth?response_type=code"
        + "&client_id=" + access.clientId
        + "&redirect_uri=" + access.redirectUri
        + "&scope=" + access.scope
        + "&access_type=" + access.accessType;
    }

    public void GetToken(Action<string,string> OnSuccess, Action<string> OnFailure) {
      var url = "https://www.googleapis.com/oauth2/v4/token";
      var content = new Dictionary<string,string> () {
        { "code", access.code },
        { "client_id", access.clientId },
        { "client_secret", access.clientSecret },
        { "redirect_uri", access.redirectUri },
        { "grant_type", access.grantType },
        { "access_type", access.accessType },
      };

      StartCoroutine (Post (url, content, text => {
        var json = JSON.Parse(text);
        var accessToken = json["access_token"].RawString();
        var refreshToken = json["refresh_token"].RawString();
        OnSuccess(accessToken, refreshToken);
      }, OnFailure));
    }

    public void GetLiveChatId(string id, Action<string> OnSuccess, Action<string> OnFailure) {
      var url = "https://www.googleapis.com/youtube/v3/liveBroadcasts?part=snippet";
      url += "&id=" + id;

      StartCoroutine (Get (url, text => {
        var json = JSON.Parse(text);
        var chatId = json["items"][0]["snippet"]["liveChatId"].RawString();
        OnSuccess(chatId);
      }, OnFailure));
    }

    public void GetChatMessages(string chatId, string pageToken, Action<Chat> OnSuccess, Action<string> OnFailure) {
      var url = "https://www.googleapis.com/youtube/v3/liveChat/messages?part=snippet,authorDetails";
      url += "&liveChatId=" + chatId;
      url += pageToken == "" ? "" : "&pageToken=" + pageToken;

      StartCoroutine (Get (url, text => {
        var chat = new Chat();

        var json = JSON.Parse(text);
        var items = json["items"];

        foreach (var item in items) {
          var snip = item.Value["snippet"];
          var author = item.Value["authorDetails"];
          chat.msgs.Add(new Chat.Msg() {
            text = snip["displayMessage"].RawString(),
            name = author["displayName"].RawString(),
            img = author["profileImageUrl"].RawString()
          });
        }

        var next = json["nextPageToken"];
        chat.pageToken = next;

        OnSuccess(chat);
      }, OnFailure));
    }

    IEnumerator Get(string uri, Action<string> OnSuccess, Action<string> OnFailure) {
      var content = new Dictionary<string,string> () {
        { "Authorization", "Bearer " + access.token }
      };
      yield return Get (uri, content, OnSuccess, OnFailure);
    }

    IEnumerator Get(string uri, Dictionary<string,string> content, Action<string> OnSuccess, Action<string> OnFailure) {
      UnityWebRequest request = UnityWebRequest.Get (uri);
      foreach (var d in content) {
        request.SetRequestHeader (d.Key, d.Value);
      }
      yield return request.SendWebRequest();

      if (request.isNetworkError) {
        OnFailure("[Network Error]");
      } else if (request.isHttpError) {
        OnFailure(request.downloadHandler.text);
      } else {
        OnSuccess(request.downloadHandler.text);
      }
    }

    IEnumerator Post(string uri, Dictionary<string,string> content, Action<string> OnSuccess, Action<string> OnFailure) {
      UnityWebRequest request = UnityWebRequest.Post (uri, content);
      yield return request.SendWebRequest();

      if (request.isNetworkError) {
        OnFailure("[Network Error]");
      } else if (request.isHttpError) {
        OnFailure(request.downloadHandler.text);
      } else {
        OnSuccess(request.downloadHandler.text);
      }
    }

  }

  public static class SimpleJsonUtility {
    public static string RawString(this JSONNode node) {
      var len = node.ToString ().Length - 2;
      return node.ToString ().Substring (1, len);
    }
  }
}

YtlController.cs

using System.Collections;
using System.Collections.Generic;
using System;
using UnityEngine;

namespace YouTubeLive {
  [RequireComponent(typeof(YtlClient))]
  [RequireComponent(typeof(YtlServer))]
  public class YtlController : MonoBehaviour {
    [SerializeField]
    Access access;

    [SerializeField]
    float interval = 3f;

    public event Action<Chat.Msg> OnMessage;

    IEnumerator Start() {
      OnMessage += _ => {};

      var client = GetComponent<YtlClient> ();
      client.access = access;
      yield return null;

      if (access.code == "") {
        var server = GetComponent<YtlServer>();

        server.Listen();
        server.OnReceiveCode += code => {
          access.code = code;
        };
        yield return null;

        Application.OpenURL (client.AuthUrl());
        yield return new WaitUntil (() => access.code != "");
        server.Stop ();
      }

      if (access.token == "") {
        client.GetToken((token,_) => {
          access.token = token;
        }, err => {
          Debug.Log("GetToken>" + err);
        });
        yield return new WaitUntil (() => access.token != "");
      }

      var chatId = "";
      client.GetLiveChatId (access.id, c => {
        chatId = c;
      }, err => {
        Debug.Log("GetLiveChatId>" + err);
      });
      yield return new WaitUntil (() => chatId != "");

      var pageToken = "";
      while (true) {
        client.GetChatMessages(chatId, pageToken, chat => {
          foreach (var msg in chat.msgs) {
            OnMessage(msg);
          }
          pageToken = chat.pageToken;
        }, err => Debug.Log("GetChatMessages>" + err));

        yield return new WaitForSeconds (interval);
      }
    }

  }

}

YtlServer.cs

using System.Collections;
using System.Collections.Generic;
using System.Threading;
using System.Net;
using System.Text;
using System.Text.RegularExpressions;
using System;
using UnityEngine;

namespace YouTubeLive {
  public class YtlServer : MonoBehaviour {
    HttpListener listener;
    bool isRunning;

    Queue<string> queue = new Queue<string>();

    public event Action<string> OnReceiveCode;

    public void Listen() {
      ThreadStart start = () => {
        try {
          listener = new HttpListener();
          listener.Prefixes.Add("http://*:8080/");
          listener.Start();

          isRunning = true;
          while (isRunning) {
            var context = listener.GetContext();
            var req = context.Request;
            var res = context.Response;

            var code = ExtractCode(req.RawUrl);
            if (code != "") {
              queue.Enqueue(code);
            }

            var content = Encoding.UTF8.GetBytes(req.RawUrl);
            res.StatusCode = 200;
            res.OutputStream.Write(content, 0, content.Length);
            res.Close();
          }
        } catch (Exception e) {
          Debug.LogError(e);
        }
      };

      var thread = new Thread (start);
      thread.Start ();
    }

    public void Stop() {
      if (isRunning) {
        listener.Close ();
        isRunning = false;
      }
    }

    void Update() {
      if (queue.Count > 0) {
        var item = queue.Dequeue ();

        if (OnReceiveCode != null) {
          OnReceiveCode(item);
        }
      }
    }

    void OnDestory() {
      Stop ();
    }

    public static string ExtractCode(string rawUrl) {
      var re = new System.Text.RegularExpressions.Regex (@"/\?code=(?<c>.*)");
      return re.Match (rawUrl).Groups ["c"].ToString();
    }

  }
}

YtlTest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace YouTubeLive {
  [RequireComponent(typeof(YtlController))]
  public class YtlTest : MonoBehaviour {
    void Start () {
      var ctrl = GetComponent<YtlController> ();
      ctrl.OnMessage += msg => {
        Debug.Log(msg.name + ": " + msg.text);
      };
    }
  }
}

使用例

public class Rotater : MonoBehaviour {
  [SerializeField]
  Transform character;

  [SerializeField]
  YouTubeLive.YtlController ctrl;

  float tgt;
  float speed;

  void Start() {
    Application.runInBackground = true;

    ctrl.OnMessage += msg => {
      tgt += msg.text.Length * 5f;
    };
  }

  void Update() {
    speed = Mathf.Lerp (tgt, speed, Time.deltaTime);

    transform.Rotate (Vector3.up, speed * Time.deltaTime);

    var animator = character.GetComponent<Animator> ();
    animator.SetFloat ("Speed", speed);
  }

}