diff --git a/chat-signaling-server/templates/index.html b/chat-signaling-server/templates/index.html
index ef0b3b7..5c1a530 100644
--- a/chat-signaling-server/templates/index.html
+++ b/chat-signaling-server/templates/index.html
@@ -12,330 +12,530 @@
         <select id="peers">
 
         </select>
-        <input id="message-input" />
-        <input type="file" id="sendfile" disabled/>
+        <input id="message-input" disabled />
+        <input type="file" id="sendfile" disabled />
     </div>
 </div>
 {% endblock %}
 {% block pagescripts %}
 <script>
-(() => {
-    let message_list = document.getElementById("message-list")
-    let peers = document.getElementById("peers")
-    let inputbox = document.getElementById("message-input")
-    let sendfile = document.getElementById("sendfile")
+    (() => {
+        const MessageBootstrap = "Bootstrap";
+        const MessageDiscoverRequest = "DiscoverRequest";
+        const MessageDiscoverResponse = "DiscoverResponse";
+        const MessageSessionOffer = "SessionOffer";
+        const MessageSessionAnswer = "SessionAnswer";
+        const MessageICECandidate = "IceCandidate";
 
-    let search = new URLSearchParams(location.search);
-    let sender = search.get("name") || "";
-    
-    let room = search.get("room") || "public";
+        function ChatRoom(room, name, ui, options) {
+            options = options || {};
+            let { iceServers } = options;
 
-    let peerMap = new Map();
-    let channelMap = new Map();
+            this.room = room;
+            this.name = name;
+            this.iceServers = iceServers;
 
-    let ws;
-    let wsReconnectInterval = 5000;
+            this.peers = new Map();
+            this.channels = new Map();
+            this.i_am_polite = new Map();
+            this.i_am_offering = new Map();
 
-    const MessageBootstrap = "Bootstrap";
-    const MessageDiscoverRequest = "DiscoverRequest";
-    const MessageDiscoverResponse = "DiscoverResponse";
-    const MessageSessionOffer = "SessionOffer";
-    const MessageSessionAnswer = "SessionAnswer";
-    const MessageICECandidate = "IceCandidate";
+            this.ws = null;
 
-    let updateSendfile = () => {
-        if (peers.value != "") {
-            sendfile.removeAttribute("disabled")
-        } else {
-            sendfile.setAttribute("disabled", "")
+            this.ui = ui;
+
+            this.event = new EventTarget();
         }
-    }
-    peers.addEventListener("change", updateSendfile)
-    sendfile.addEventListener("change", async (ev) => {
-        let file = sendfile.files[0]
-        sendfile.value = ""
 
-        let peer = peerMap.get(peers.value)
-        if (!peer) {
-            return
-        }
-        display(`你给 ${peers.value} 传了一个文件: ${file.name}。传输中...`)
+        let nativeEvent = window.Event;
+        function Event(type, data) {
+            let event = new nativeEvent(type);
 
-        let reader = new FileReader()
-        let dc = peer.createDataChannel(`file:${file.name}`)
-        reader.addEventListener("load", (ev) => {
-            dc.send(reader.result)
-            dc.close()
-        })
-        dc.addEventListener("open", () => {
-            reader.readAsArrayBuffer(file)
-        })
-    })
-
-    const createNode = (tag, ...children) => {
-        let node = document.createElement(tag)
-        children.forEach(child => {
-            if(typeof child === "string") {
-                let inner = document.createElement("span")
-                inner.innerHTML = child
-                node.appendChild(inner)
-            } else if (child instanceof HTMLElement) {
-                node.appendChild(child)
-            } else {
-                console.log("child is not a node: ", child, typeof child)
+            if (data) {
+                for (let [k, v] of Object.entries(data)) {
+                    event[k] = v
+                }
             }
-        })
-        return node
-    }
 
-    const display = (...message) => {
-        let scrollToBottom = Math.abs(message_list.scrollHeight - message_list.scrollTop - message_list.clientHeight) < 1;
-        message_list.appendChild(createNode("div",
-            `${new Date().toTimeString()}: `,
-            ...message
-        ))
-        if(scrollToBottom) {
-            message_list.scrollTo({
-                top: message_list.scrollHeight
-            })
-        }
-    }
-
-    inputbox.addEventListener("keyup", (e) => {
-        if (!(e.key === 'Enter' || e.keyCode === 13)) {
-            return
-        }
-        if (!inputbox.value || inputbox.value.trim().length == 0) {
-            return
-        }
-        let channel = channelMap.get(peers.value)
-        if (!channel) {
-            return
+            return event;
         }
 
-        display(`你 -> ${peers.value}: ${inputbox.value}`)
-        channel.send(inputbox.value)
-        inputbox.value = ""
-    })
+        // ---------------- Chat Room Methods ------------
 
-    const addPeer = (peerName) => {
-        display(`连接上了 ${peerName}`)
 
-        let newNode = document.createElement("option")
-        newNode.id = peerName
-        newNode.setAttribute("value", peerName)
-        newNode.innerHTML = peerName;
-        peers.appendChild(newNode)
+        // ---------------- Utilities --------------------
 
-        updateSendfile()
-    }
-    const removePeer = (peerName) => {
-        display(`${peerName} 走了...`)
-        let el = document.getElementById(peerName);
-        if(el) el.remove()
-
-        updateSendfile()
-    }
-
-    let timeout;
-    
-    let reconnect = () => {
-        if(ws && (ws.readyState == WebSocket.CONNECTING || ws.readyState == WebSocket.OPEN)) {
-            return;
-        }
-
-        let protocol = "ws://";
-        if (location.protocol === "https:") {
-            protocol = "wss://"
-        }
-        
-        ws = new WebSocket(protocol+location.host+"/ws");
-        ws.addEventListener("error", reconnect)
-        ws.addEventListener("close", reconnect)
-
-        ws.addEventListener("message", ({data}) => {
-            handle_ws_message(JSON.parse(data))
-        })
-        ws.addEventListener("open", () => {
-            display("服务器连上啦。你等等，给你起个名字...")
-            ws.send(JSON.stringify({
+        ChatRoom.prototype.kickoff = function () {
+            this.event.dispatchEvent(new Event("kickoff"))
+            this.send_message({
                 message: {
                     type: MessageBootstrap,
                 },
-                room,
-                sender,
-            }))
-        })
-    }
-
-    let handle_ws_message = (wsMessage) => {
-        let recreateAndSetupPeer = async (peerName) => {
-            if (!peerMap.has(peerName)) {
-
-                let peer = new RTCPeerConnection({
-                    iceServers: [{ urls: ["stun:nhz.jeffthecoder.xyz:3478", "stun:nhz.jeffthecoder.xyz:3479", "stun:nhz.jeffthecoder.xyz:13478"] }]
+            })
+        }
+        ChatRoom.prototype.setup_peerconnection = function (sender) {
+            peer = this.peers.get(sender);
+            if (peer == null) {
+                peer = new RTCPeerConnection({
+                    iceServers: [{ urls: this.iceServers }]
                 })
-                peer.addEventListener("signalingstatechange", (ev) => {
-                    console.log("signaling state changed: ", peer.signalingState)
-                })
-                peer.addEventListener("connectionstatechange", (ev) => {
-                    console.log("peer connection state changed: ", peer.connectionState)
-                    switch (peer.connectionState) {
-                        case "closed":
-                            break;
-                        case "disconnected":
-                        case "failed":
-                            peer.restartIce()
-                            break
+                peer.addEventListener("iceconnectionstatechange", () => {
+                    if (peer.iceConnectionState === "failed") {
+                        peer.restartIce();
                     }
                 })
+                peer.addEventListener("negotiationneeded", async (ev) => {
+                    this.on_negotiation_needed(sender)
+                })
                 peer.addEventListener("icecandidate", (ev) => {
                     if (!ev.candidate) {
-                        console.log("gather end")
                         return
                     }
+
                     let candidate = ev.candidate.toJSON()
-                    ws.send(JSON.stringify({
-                        message: {
-                            type: MessageICECandidate,
-                            candidate: JSON.stringify(candidate),
-                            sender,
-                            kind: 3,
-                        },
-                        room,
-                        sender,
-                        receiver: wsMessage.sender,
-                    }))
+                    this.on_local_ice_candidate(sender, candidate)
                 })
-                peer.addEventListener("icegatheringstatechange", ev => {
-                    console.log("gather", peer.iceGatheringState)
+                peer.addEventListener("datachannel", ({ channel }) => {
+                    this.on_datachannel(sender, channel)
                 })
-                peer.addEventListener("datachannel", ({channel}) => {
-                    if(channel.label === "chat") {
-                        channelMap.set(peerName, channel);
-                        channel.addEventListener("open", (ev) => {
-                            addPeer(peerName)
-                        })
-                        channel.addEventListener("message", (ev) => {
-                            display(`${peerName} -> You: ${ev.data}`)
-                        })
-                        channel.addEventListener("close", () => {
-                            removePeer(peerName)
-                        })
-                    } else if (channel.label.startsWith("file:")) {
-                        let filename = channel.label.substr(5)
-                        let buffers = [];
-                        channel.addEventListener("open", ev => {
-                            display(`${peerName} 给你发了一个文件: ${filename}。 接收中...`)
-                        })
-                        channel.addEventListener("message", ev => {
-                            buffers.push(ev.data)
-                        })
-                        channel.addEventListener("close", () => {
-                            var link = document.createElement('a');
-                            link.href = window.URL.createObjectURL(new Blob(buffers));
-                            link.download = filename;
-                            link.innerHTML = filename
-                            display(
-                                "文件：",
-                                link,
-                            )
-                        })
-                    }
-                })
-
-                peerMap.set(peerName, peer);
-            }
-            let peer = peerMap.get(peerName);
-
-            let resultSdp = null, resultMessageType;
-            if(wsMessage.message.type === MessageDiscoverResponse) {
-                let channel = peer.createDataChannel("chat");
-                channel.addEventListener("open", (ev) => {
-                    addPeer(peerName)
-                })
-                channel.addEventListener("message", (ev) => {
-                    display(`${peerName} -> 你: ${ev.data}`)
-                })
-                channel.addEventListener("close", () => {
-                    removePeer(peerName)
-                })
-                channelMap.set(peerName, channel);
-
-                
-                resultSdp = await peer.createOffer();
-                resultMessageType = MessageSessionOffer;
-                peer.setLocalDescription(resultSdp)
-                console.log("set local offer")
-            } else {
-                peer.setRemoteDescription(JSON.parse(wsMessage.message.sdp))
-                console.log("set remote offer")
-                resultSdp = await peer.createAnswer();
-                resultMessageType = MessageSessionAnswer;
-                peer.setLocalDescription(resultSdp)
-                console.log("set local answer")
+                this.peers.set(sender, peer);
             }
 
-            ws.send(JSON.stringify({
-                message: {
-                    type: resultMessageType,
-                    sdp: JSON.stringify(resultSdp),
+            return {
+                peer,
+            }
+        }
+
+        ChatRoom.prototype.setup_chat_datachannel = function (sender, channel) {
+            console.log("setup chat datachannel", { sender, channel })
+            channel.addEventListener("open", (ev) => {
+                this.event.dispatchEvent(new Event("chat-channel-open", {
                     sender,
-                    kind: 3,
-                },
-                room,
-                sender,
-                receiver: wsMessage.sender,
+                    channel
+                }))
+            })
+            channel.addEventListener("message", (ev) => {
+                console.log(ev)
+                this.on_chat_message(sender, ev.data)
+            })
+            channel.addEventListener("close", () => {
+                this.event.dispatchEvent(new Event("chat-channel-close", {
+                    sender,
+                    channel
+                }))
+            })
+        }
+        ChatRoom.prototype.setup_file_datachannel = function (sender, channel) {
+            let filename = channel.label.substr(5)
+            let buffers = [];
+            channel.addEventListener("open", ev => {
+                this.event.dispatchEvent(new Event("file_receiving", {
+                    filename,
+                }))
+                // this.display(`${sender} 给你发了一个文件: ${filename}。 接收中...`)
+            })
+            channel.addEventListener("message", ev => {
+                buffers.push(ev.data)
+            })
+            channel.addEventListener("close", () => {
+                this.event.dispatchEvent(new Event("file_received", {
+                    buffer: new Blob(buffers),
+                    filename
+                }))
+            })
+        }
+
+        ChatRoom.prototype.reconnect = function () {
+            this.event.dispatchEvent(new Event("ws_reconnect", { ws: this.ws }))
+            if (this.ws && (this.ws.readyState == WebSocket.CONNECTING || this.ws.readyState == WebSocket.OPEN)) {
+                return;
+            }
+
+            let protocol = "ws://";
+            if (location.protocol === "https:") {
+                protocol = "wss://"
+            }
+
+            let ws = new WebSocket(protocol + location.host + "/ws");
+            ws.addEventListener("error", (ev) => {
+                console.error("ws error", ev)
+                this.reconnect()
+            })
+            ws.addEventListener("close", () => {
+                console.warn("ws closed")
+                this.reconnect()
+            })
+
+            ws.addEventListener("message", ({ data }) => {
+                this.on_ws_message(JSON.parse(data))
+            })
+
+            ws.addEventListener("open", () => {
+                this.kickoff()
+            })
+            this.ws = ws;
+        }
+
+        ChatRoom.prototype.send_message = function (message) {
+            this.event.dispatchEvent(new Event("send_wsmessage", { message }))
+            console.trace("sending message", message)
+            this.ws.send(JSON.stringify({
+                room: this.room,
+                sender: this.name,
+                ...message
             }))
         }
 
-        let peer = peerMap.get(wsMessage.sender)
-        
-        switch (wsMessage.message.type) {
-            case MessageBootstrap:
-                sender = wsMessage.sender;
-                ws.send(JSON.stringify({
-                        message: {
-                            type: MessageDiscoverRequest,
-                        },
-                        room,
-                        sender: wsMessage.sender,
-                    }))
-                display(`决定了，就叫 ${sender}. 我们等等小伙伴吧...`)
-                break;
-            case MessageDiscoverRequest:
-                display(`正在尝试连接 ${wsMessage.sender}`)
-                ws.send(JSON.stringify({
-                    message: {
-                        type: MessageDiscoverResponse,
-                    },
-                    room,
-                    sender,
-                    receiver: wsMessage.sender,
-                }))
-                break
-            case MessageDiscoverResponse:
-                recreateAndSetupPeer(wsMessage.sender)
-                break;
-            case MessageSessionOffer:
-                recreateAndSetupPeer(wsMessage.sender)
-                break
-            case MessageSessionAnswer:
-                console.log("set remote answer")
-                peer.setRemoteDescription(JSON.parse(wsMessage.message.sdp))
-                peer.restartIce()
-                break
-            case MessageICECandidate:
-                let candidate = JSON.parse(wsMessage.message.candidate);
-                if(!peer) {
-                    console.warn("candidate dropped", candidate)
-                    return
-                }
-                peer.addIceCandidate(candidate)
-        }
-    }
+        // ----------------- Message from websocket --------------
 
-    reconnect()
-})()
+
+
+        ChatRoom.prototype.on_ws_message = function (wsMessage) {
+            this.event.dispatchEvent(new Event("recv_wsmessage", { wsMessage }))
+            console.trace("receiving message", wsMessage)
+            switch (wsMessage.message.type) {
+                case MessageBootstrap:
+                    this.on_bootstrap(wsMessage);
+                    break;
+                case MessageDiscoverRequest:
+                    this.on_discover_request(wsMessage)
+                    break
+                case MessageDiscoverResponse:
+                    this.on_discover_response(wsMessage)
+                    break;
+                case MessageSessionOffer:
+                    this.on_session_message(wsMessage)
+                    break
+                case MessageSessionAnswer:
+                    this.on_session_message(wsMessage)
+                    break
+                case MessageICECandidate:
+                    this.on_remote_ice_candidate(wsMessage)
+            }
+        }
+
+        ChatRoom.prototype.on_bootstrap = function ({ sender, iceServers }) {
+            this.event.dispatchEvent(new Event("bootstrap", { sender }))
+            this.name = sender;
+            this.iceServers = iceServers || this.iceServers || ["stun:nhz.jeffthecoder.xyz:3478", "stun:nhz.jeffthecoder.xyz:3479", "stun:nhz.jeffthecoder.xyz:13478"];
+
+            this.send_message({
+                message: {
+                    type: MessageDiscoverRequest,
+                },
+            })
+        }
+
+
+        ChatRoom.prototype.on_discover_request = function ({ sender }) {
+            this.event.dispatchEvent(new Event("discover_request", { sender }))
+
+            this.i_am_polite.set(sender, false)
+            this.setup_peerconnection(sender)
+
+            this.send_message({
+                message: {
+                    type: MessageDiscoverResponse,
+                },
+                receiver: sender,
+            })
+        }
+
+        ChatRoom.prototype.on_discover_response = async function ({ sender }) {
+            this.i_am_polite.set(sender, true)
+            let { peer } = this.setup_peerconnection(sender);
+
+            let channel = peer.createDataChannel("chat");
+            this.setup_chat_datachannel(sender, channel)
+            this.channels.set(sender, channel)
+        }
+
+        ChatRoom.prototype.on_session_message = async function ({ sender, message }) {
+            let description = JSON.parse(message.sdp)
+            let polite = this.i_am_polite.get(sender);
+            let makingOffer = this.i_am_offering.get(sender) || false;
+            let peer = this.peers.get(sender)
+
+            console.log("on session message", { message, description, polite, makingOffer })
+
+            const offerCollision =
+                description.type === "offer" &&
+                (makingOffer || peer.signalingState !== "stable");
+
+            ignoreOffer = !polite && offerCollision;
+            if (ignoreOffer) {
+                return;
+            }
+
+            await peer.setRemoteDescription(description);
+            if (description.type === "offer") {
+                await peer.setLocalDescription();
+                this.event.dispatchEvent(new Event("offer", { sender, description }))
+
+                this.send_message({
+                    message: {
+                        type: MessageSessionAnswer,
+                        sdp: JSON.stringify(peer.localDescription),
+                        sender: this.name,
+                        kind: 3,
+                    },
+                    receiver: sender,
+                })
+            }
+        }
+
+        ChatRoom.prototype.on_remote_ice_candidate = function ({ sender, message }) {
+            let candidate = JSON.parse(message.candidate);
+            this.event.dispatchEvent(new Event("candidate", { sender, candidate }))
+
+            let peer = this.peers.get(sender)
+            console.log("remote_candidate", sender, message)
+            peer.addIceCandidate(candidate)
+        }
+
+        // ----------------- webrtc state & events -----------------
+
+        ChatRoom.prototype.on_negotiation_needed = async function (sender) {
+            let polite = this.i_am_polite.get(sender);
+            console.log("negotiationneeded", { sender, polite })
+
+            let peer = this.peers.get(sender);
+            this.i_am_offering.set(sender, true)
+            try {
+                await peer.setLocalDescription();
+                this.send_message({
+                    message: {
+                        type: MessageSessionOffer,
+                        sdp: JSON.stringify(peer.localDescription),
+                        sender: this.name,
+                        kind: 3,
+                    },
+                    receiver: sender,
+                })
+            } finally {
+                this.i_am_offering.delete(sender)
+            }
+        }
+
+        ChatRoom.prototype.on_local_ice_candidate = function (sender, candidate) {
+            this.event.dispatchEvent(new Event("candidate", { candidate }))
+            this.send_message({
+                message: {
+                    type: MessageICECandidate,
+                    candidate: JSON.stringify(candidate),
+                    sender: this.name,
+                    kind: 3,
+                },
+                receiver: sender,
+            })
+        }
+
+        ChatRoom.prototype.on_chat_message = function (sender, data) {
+            this.event.dispatchEvent(new Event("chat_message", { sender, data }))
+        }
+
+        ChatRoom.prototype.on_channel_open = function (sender, channel) {
+            this.event.dispatchEvent(new Event("channel_open", { data }))
+        }
+
+        ChatRoom.prototype.on_channel_close = function (sender, channel) {
+            this.event.dispatchEvent(new Event("channel_close", { data }))
+        }
+
+        ChatRoom.prototype.on_datachannel = function (sender, channel) {
+            console.trace("on datachannel", sender, channel)
+            if (channel.label === "chat") {
+                this.channels.set(sender, channel);
+                this.setup_chat_datachannel(sender, channel)
+            } else if (channel.label.startsWith("file:")) {
+                this.setup_file_datachannel(sender, channel)
+            }
+        }
+
+        // ----------------------------------------------------------
+
+        function ChatUI(messages, peerOptions, inputbox, sendfile) {
+            this.messages = messages;
+            this.peerOptions = peerOptions;
+            this.inputbox = inputbox;
+            this.sendfile = sendfile;
+
+            this.receiver = null;
+
+            this.event = new EventTarget();
+        }
+
+
+        ChatUI.prototype.setup = function () {
+            this.sendfile.addEventListener("change", e => this.on_sendfile_changed(e))
+            this.peerOptions.addEventListener("change", e => this.on_peer_list_changed(e))
+            this.inputbox.addEventListener("keyup", e => this.on_key_up(e))
+        }
+
+        ChatUI.prototype.on_peer_list_changed = function () {
+            this.receiver = this.peerOptions.value;
+            if (this.peerOptions.value != "") {
+                this.sendfile.removeAttribute("disabled")
+                this.inputbox.removeAttribute("disabled")
+            } else {
+                this.sendfile.setAttribute("disabled", "")
+                this.inputbox.setAttribute("disabled", "")
+            }
+        }
+
+        ChatUI.prototype.on_key_up = function (e) {
+            if (!(e.key === 'Enter' || e.keyCode === 13)) {
+                return
+            }
+            if (!this.inputbox.value || this.inputbox.value.trim().length == 0) {
+                return
+            }
+
+
+            let value = this.inputbox.value;
+            let receiver = this.receiver;
+
+            this.event.dispatchEvent(new Event("send_message", {
+                value,
+                receiver,
+            }))
+            this.inputbox.value = ""
+        }
+
+        ChatUI.prototype.on_sendfile_changed = function () {
+            let file = sendfile.files[0]
+            let receiver = this.receiver;
+            sendfile.value = ""
+
+            this.display(`你给 ${this.receiver} 传了一个文件: ${file.name}。传输中...`)
+
+            // let reader = new FileReader()
+            // let dc = peer.createDataChannel(`file:${file.name}`)
+            // reader.addEventListener("load", (ev) => {
+            //     dc.send(reader.result)
+            //     dc.close()
+            // })
+            // dc.addEventListener("open", () => {
+            //     reader.readAsArrayBuffer(file)
+            // })
+            this.event.dispatchEvent(new Event("send_file", {
+                file,
+                receiver,
+            }))
+        }
+
+        ChatUI.prototype.add_peer = function (peerName) {
+            let newNode = document.createElement("option")
+            newNode.id = `peer-${peerName}`
+            newNode.setAttribute("value", peerName)
+            newNode.innerHTML = peerName;
+            this.peerOptions.appendChild(newNode)
+
+            this.on_peer_list_changed()
+        }
+        ChatUI.prototype.remove_peer = function (peerName) {
+            let el = document.getElementById(`peer-${peerName}`);
+            if (el) el.remove()
+
+            this.on_peer_list_changed()
+        }
+
+        ChatUI.prototype.display = function (...message) {
+            let message_list = this.messages;
+
+            let scrollToBottom = Math.abs(message_list.scrollHeight - message_list.scrollTop - message_list.clientHeight) < 1;
+            message_list.appendChild(createNode("div",
+                `${new Date().toTimeString()}: `,
+                ...message
+            ))
+            if (scrollToBottom) {
+                message_list.scrollTo({
+                    top: message_list.scrollHeight
+                })
+            }
+        }
+
+        let message_list = document.getElementById("message-list")
+        let peers = document.getElementById("peers")
+        let inputbox = document.getElementById("message-input")
+        let sendfile = document.getElementById("sendfile")
+
+        const createNode = (tag, ...children) => {
+            let node = document.createElement(tag)
+            children.forEach(child => {
+                if (typeof child === "string") {
+                    let inner = document.createElement("span")
+                    inner.innerHTML = child
+                    node.appendChild(inner)
+                } else if (child instanceof HTMLElement) {
+                    node.appendChild(child)
+                } else {
+                    console.log("child is not a node: ", child, typeof child)
+                }
+            })
+            return node
+        }
+
+
+        let search = new URLSearchParams(location.search);
+
+        let room = new ChatRoom(search.get("room") || "public", search.get("name") || "", undefined, {})
+        let ui = new ChatUI(message_list, peers, inputbox, sendfile);
+        ui.setup()
+
+        room.event.addEventListener("kickoff", () => {
+            ui.display("服务器连上啦。你等等，给你起个名字...")
+        })
+        room.event.addEventListener("chat-channel-open", ({ channel, sender }) => {
+            ui.display(`${sender} 连上了`)
+            ui.add_peer(sender)
+        })
+        room.event.addEventListener("chat-channel-closed", ({ channel, sender }) => {
+            ui.display(`${sender} 断开了`)
+            ui.remove_peer(sender)
+        })
+
+        room.event.addEventListener("chat_message", ({ sender, data }) => {
+            ui.display(`${sender} -> 你: ${data}`)
+        })
+        room.event.addEventListener("file_received", ({ filename, buffer }) => {
+            var link = document.createElement('a');
+            link.href = window.URL.createObjectURL(buffer);
+            link.download = filename;
+            link.innerHTML = filename;
+            ui.display(
+                "文件：",
+                link,
+            )
+        })
+
+        ui.event.addEventListener("send_message", ({ receiver, value }) => {
+            let channel = room.channels.get(receiver)
+            if (!channel) {
+
+                ui.display(`${receiver} 没准备好，这条消息发不出去: ${value}`)
+                return
+            }
+            ui.display(`你 -> ${receiver}: ${value}`)
+            channel.send(value)
+        })
+        ui.event.addEventListener("send_file", ({file,receiver}) => {
+            let peer = room.peers.get(receiver);
+
+            let reader = new FileReader()
+            let dc = peer.createDataChannel(`file:${file.name}`)
+            reader.addEventListener("load", (ev) => {
+                dc.send(reader.result)
+                dc.close()
+            })
+            dc.addEventListener("open", () => {
+                reader.readAsArrayBuffer(file)
+            })
+        })
+
+        let display = ui.display.bind(ui);
+
+        room.reconnect()
+    })()
 </script>
 {% endblock %}
\ No newline at end of file