add most of the client connection protocol

client/Connection.ts

@@ -0,0 +1,96 @@
+import Transport from "./Transport";
+
+
+type ObjectValues<T> = T[keyof T];
+const C2SRequestTypes = {
+  HTTPRequest: 0,
+  WSOpen: 1,
+  WSClose: 2,
+  WSSendText: 3,
+  WSSendBinary: 4,
+} as const;
+type C2SRequestType = ObjectValues<typeof C2SRequestTypes>
+
+const S2CRequestTypes = {
+  HTTPResponse: 0,
+  WSOpen: 1,
+  WSDataText: 2,
+  WSDataBinary: 3,
+} as const;
+type S2CRequestType = ObjectValues<typeof S2CRequestTypes>
+
+
+
+
+export default class Connection {
+
+
+  callbacks: Record<number, Function> = {};
+
+  counter: number = 0;
+
+  constructor(public transport: Transport) {
+
+    transport.ondata = this.ondata.bind(this);
+  }
+
+  ondata(data: ArrayBuffer) {
+    let cursor = 0;
+    const view = new DataView(data);
+
+    let requestID = view.getUint16(cursor);
+    cursor += 2;
+    let requestType = view.getUint8(cursor) as S2CRequestType;
+    cursor += 1;
+
+    console.log(requestID, requestType);
+
+    switch (requestType) {
+      case S2CRequestTypes.HTTPResponse: {
+        let decoder = new TextDecoder();
+        let text = decoder.decode(data.slice(cursor));
+        console.log(text);
+        let json = JSON.parse(text);
+
+        console.log(requestID);
+
+        this.callbacks[requestID](json);
+        break;
+      }
+    }
+  }
+
+  async send(data: ArrayBuffer | Blob, type: C2SRequestType): Promise<number> {
+
+    let requestID = this.counter++;
+
+    let header = new ArrayBuffer(2 + 1);
+    let view = new DataView(header);
+
+    let cursor = 0;
+
+    view.setUint16(cursor, requestID);
+    cursor += 2;
+    view.setUint8(cursor, type);
+    cursor += 1;
+
+    let buf = await new Blob([header, data]).arrayBuffer();
+
+    this.transport.send(buf);
+    console.log(buf);
+
+    return requestID;
+
+  }
+
+  httprequest(data: object): Promise<object> {
+    let json = JSON.stringify(data);
+
+    return new Promise(async (resolve) => {
+
+      let id = this.counter;
+      this.callbacks[id] = resolve;
+      await this.send(new Blob([json]), C2SRequestTypes.HTTPRequest);
+    });
+  }
+}