Create server.js

server.js

@@ -0,0 +1,150 @@
+import Koa from "koa";
+import Router from "@koa/router";
+import compose from "koa-compose";
+import { koaBody } from "koa-body";
+import {
+  handleTimeStap,
+  handleBase64,
+  handleNewSession,
+  handleErrors,
+  initParams,
+} from "./handles.js";
+import https from "https";
+import { createParser } from "eventsource-parser";
+const app = new Koa();
+const router = new Router();
+const params = {};
+const break_message = {
+  answer_message_id: null,
+  query_message_id: null,
+  scene: params.scene,
+  broken_pos: 0,
+  conversation_id: params.conversation_id,
+  local_message_id: params.local_message_id,
+};
+
+const createNewSession = async (ctx, next) => {
+  const { messages } = ctx.request.body;
+  const sessionid = ctx.req.headers.authorization.split(" ")[1];
+  if (
+    messages[0].role === "system" &&
+    messages.length === 2 &&
+    break_message.answer_message_id !== null &&
+    break_message.query_message_id !== null
+  ) {
+    console.log("new session");
+    await handleNewSession(break_message, sessionid);
+    params.conversation_id =
+      "7337495393033765890_7337496580645339154_2_" + handleTimeStap();
+    params.local_message_id = handleBase64();
+  }
+  await next();
+};
+
+// 事件源路由
+router.post("/api/v1/chat/completions", async (ctx) => {
+  ctx.respond = false;
+  ctx.type = "text/event-stream";
+  ctx.status = 200;
+  // 初始化响应头 sse
+  ctx.set({
+    "Cache-Control": "no-cache",
+    Connection: "keep-alive",
+    "Content-Encoding": "none",
+  });
+  // 获取 post 请求的 body
+  const { messages, model } = ctx.request.body;
+  const sessionid = ctx.req.headers.authorization.split(" ")[1];
+  // 返回的数据
+  const sseData = {
+    id: null,
+    object: "chat.completion.chunk",
+    created: handleTimeStap(),
+    model: model,
+    system_fingerprint: null,
+    choices: [
+      {
+        index: 0,
+        delta: { content: null },
+        logprobs: null,
+        finish_reason: null,
+      },
+    ],
+  };
+  // 远程服务器配置
+  const options = {
+    hostname: "www.coze.com",
+    path: "/api/conversation/chat",
+    port: 443,
+    method: "POST",
+    headers: {
+      "Content-Type": "application/json",
+      Cookie: `sessionid=${sessionid}`,
+      "User-Agent":
+        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36",
+    },
+  };
+  params.query = messages[messages.length - 1].content;
+  const sse = https.request(options);
+
+  sse.on("response", async (res) => {
+    const parser = createParser((event) => {
+      if (event.event === "message") {
+        const data = JSON.parse(event.data);
+        if (data.message.type === "answer") {
+          sseData.id = data.conversation_id;
+          sseData.choices[0].delta.content = data.message.content;
+          if (data.is_finish) {
+            sseData.choices[0].finish_reason = "stop";
+          } else {
+            sseData.choices[0].finish_reason = null;
+          }
+          ctx.res.write(`data:${JSON.stringify(sseData)}\n\n`);
+          if (data.is_finish) {
+            break_message.answer_message_id = data.message.reply_id;
+            break_message.query_message_id = data.message.message_id;
+            break_message.broken_pos = parseInt(
+              data.message.extra_info.output_tokens
+            );
+            ctx.res.end();
+          }
+        }
+      }
+    });
+    res.setEncoding("utf8");
+    res.on("data", (d) => {
+      parser.feed(d);
+    });
+    res.on("end", () => {
+      console.log("response end", new Date().toLocaleString());
+    });
+  });
+  sse.on("error", async (e) => {
+    console.error(`problem with request: ${e.message}`);
+  });
+  sse.on("close", async () => {
+    console.log("sse closed", new Date().toLocaleString());
+  });
+
+  sse.write(JSON.stringify(params));
+  sse.end();
+  ctx.respond = false;
+});
+
+// 组合中间件
+const all = compose([
+  handleErrors,
+  koaBody(),
+  createNewSession,
+  router.routes(),
+  router.allowedMethods(),
+]);
+
+// 注册中间件
+app.use(all);
+
+// 启动Koa应用
+app.listen(3000, () => {
+  console.log("Server started on port 3000");
+  initParams(params);
+});