//信令服务器代码请转到入门教程03

var connection = new WebSocket('ws://localhost:9090'); 
var name = ""; 
 
var loginInput = document.querySelector('#loginInput'); 
var loginBtn = document.querySelector('#loginBtn'); 
var otherUsernameInput = document.querySelector('#otherUsernameInput'); 
var connectToOtherUsernameBtn = document.querySelector('#connectToOtherUsernameBtn'); 
var connectedUser, myConnection;
  
//当一个用户点击登录 
loginBtn.addEventListener("click", function(event){ 
   name = loginInput.value; 
   
   if(name.length > 0){ //发送一个message{ 
         type: "login", 
         name: name 
      }
      send({ 
         type: "login", 
         name: name 
      }); 
   } 
   
});
  
//handle messages from the server 
connection.onmessage = function (message) { 
   console.log("Got message", message.data);
   var data = JSON.parse(message.data); 
   
   switch(data.type) { 
      case "login": 
         onLogin(data.success); 
         break; 
      case "offer": 
         onOffer(data.offer, data.name); 
         break; 
      case "answer": 
         onAnswer(data.answer); 
         break; 
      case "candidate": 
         onCandidate(data.candidate); 
         break; 
      default: 
         break; 
   } 
};
  
//当用户登录
function onLogin(success) { 

   if (success === false) { //重名了
      alert("oops...try a different username"); 
   } else { 
      //创建RTCPeerConnection对象 
      
      var configuration = { 
         "iceServers": [{ "url": "stun:stun.1.google.com:19302" }] 
      }; 
      
      myConnection = new webkitRTCPeerConnection(configuration); 
      console.log("RTCPeerConnection object was created"); 
      console.log(myConnection); 
  
      //setup ice handling
      //当浏览器发现一个ICE候选我们就发送给其他人。 
      myConnection.onicecandidate = function (event) { 
      
         if (event.candidate) { 
            send({ 
               type: "candidate", 
               candidate: event.candidate 
            }); 
         } 
      }; 
   } 
};
  
connection.onopen = function () { 
   console.log("Connected"); 
};
  
connection.onerror = function (err) { 
   console.log("Got error", err); 
};
  
// 发送JSON格式message的Alias(别名) 
function send(message) { 

   if (connectedUser) { 
      message.name = connectedUser; 
   } 
   
   connection.send(JSON.stringify(message)); 
};

//setup a peer connection with another user 
connectToOtherUsernameBtn.addEventListener("click", function () { 
 
   var otherUsername = otherUsernameInput.value; 
   connectedUser = otherUsername;
   
   if (otherUsername.length > 0) { 
      //make an offer 
      myConnection.createOffer(function (offer) { 
         console.log(); 
         send({ 
            type: "offer", 
            offer: offer 
         });
         
         myConnection.setLocalDescription(offer); 
      }, function (error) { 
         alert("An error has occurred."); 
      }); 
   } 
}); 
 
//当有人想打给我们 
function onOffer(offer, name) { 
   connectedUser = name; 
   myConnection.setRemoteDescription(new RTCSessionDescription(offer)); 
   
   myConnection.createAnswer(function (answer) { 
      myConnection.setLocalDescription(answer); 
      
      send({ 
         type: "answer", 
         answer: answer 
      }); 
      
   }, function (error) { 
      alert("oops...error"); 
   }); 
}
  
//另一个用户要answer我们的offer
function onAnswer(answer) { 
   myConnection.setRemoteDescription(new RTCSessionDescription(answer)); 
} 
 
//当我们收到ICE候选
function onCandidate(candidate) { 
   myConnection.addIceCandidate(new RTCIceCandidate(candidate)); 
}