change to stream api mode

src/app.tsx

@@ -1,7 +1,7 @@
 import { useEffect, useState } from "preact/hooks";
 import "./global.css";
 
-import ChatGPT, { Message } from "./chatgpt";
+import ChatGPT, { Message, ChunkMessage } from "./chatgpt";
 import { createRef } from "preact";
 
 export interface ChatStore {
@@ -79,6 +79,7 @@ export function App() {
 
   const [inputMsg, setInputMsg] = useState("");
   const [showGenerating, setShowGenerating] = useState(false);
+  const [generatingMessage, setGeneratingMessage] = useState("");
 
   const client = new ChatGPT(chatStore.apiKey);
 
@@ -89,8 +90,65 @@ export function App() {
     client.messages = chatStore.history.slice(chatStore.postBeginIndex);
 
     // call api, return reponse text
-    const response = await client.complete();
-    chatStore.history.push({ role: "assistant", content: response });
+    const response = await client.completeWithSteam();
+    console.log("response", response);
+    const reader = response.body?.getReader();
+    const allChunkMessage: string[] = [];
+    await new ReadableStream({
+      async start(controller) {
+        while (true) {
+          let responseDone = false;
+          let state = await reader?.read();
+          let done = state?.done;
+          let value = state?.value;
+          if (done) break;
+          let text = new TextDecoder().decode(value);
+          // console.log("text:", text);
+          const lines = text
+            .trim()
+            .split("\n")
+            .map((line) => line.trim())
+            .filter((i) => {
+              if (!i) return false;
+              if (i === "data: [DONE]") {
+                responseDone = true;
+                return false;
+              }
+              return true;
+            });
+          console.log("lines", lines);
+          const jsons: ChunkMessage[] = lines
+            .map((line) => {
+              return JSON.parse(line.trim().slice("data: ".length));
+            })
+            .filter((i) => i);
+          // console.log("jsons", jsons);
+          const chunkText = jsons
+            .map((j) => j.choices[0].delta.content ?? "")
+            .join("");
+          // console.log("chunk text", chunkText);
+          allChunkMessage.push(chunkText);
+          setGeneratingMessage(allChunkMessage.join(""));
+          if (responseDone) break;
+        }
+
+        // console.log("push to history", allChunkMessage);
+        chatStore.history.push({
+          role: "assistant",
+          content: allChunkMessage.join(""),
+        });
+        // manually copy status from client to chatStore
+        chatStore.maxTokens = client.max_tokens;
+        chatStore.tokenMargin = client.tokens_margin;
+        chatStore.totalTokens =
+          client.total_tokens +
+          39 +
+          client.calculate_token_length(allChunkMessage.join(""));
+        setChatStore({ ...chatStore });
+        setGeneratingMessage("");
+        setShowGenerating(false);
+      },
+    });
 
     // manually copy status from client to chatStore
     chatStore.maxTokens = client.max_tokens;
@@ -112,8 +170,6 @@ export function App() {
       await _complete();
     } catch (error) {
       alert(error);
-    } finally {
-      setShowGenerating(false);
     }
   };
 
@@ -304,7 +360,10 @@ export function App() {
             );
           })}
           {showGenerating && (
-            <p className="animate-pulse">Generating... please wait...</p>
+            <p className="p-2 my-2 animate-pulse">
+              {generatingMessage ? generatingMessage : "生成中，保持网络稳定喵"}
+              ...
+            </p>
           )}
         </div>
         <div className="flex justify-between">

src/chatgpt.ts

@@ -3,6 +3,12 @@ export interface Message {
   content: string;
 }
 
+export interface ChunkMessage {
+  choices: {
+    delta: { role: "assitant" | undefined; content: string | undefined };
+  }[];
+}
+
 class Chat {
   OPENAI_API_KEY: string;
   messages: Message[];
@@ -33,6 +39,24 @@ class Chat {
     this.apiEndpoint = apiEndPoint;
   }
 
+  _fetch() {
+    return fetch(this.apiEndpoint, {
+      method: "POST",
+      headers: {
+        Authorization: `Bearer ${this.OPENAI_API_KEY}`,
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({
+        model: "gpt-3.5-turbo",
+        messages: [
+          { role: "system", content: this.sysMessageContent },
+          ...this.messages,
+        ],
+        stream: true,
+      }),
+    });
+  }
+
   async fetch(): Promise<{
     id: string;
     object: string;
@@ -49,21 +73,8 @@ class Chat {
       index: number | undefined;
     }[];
   }> {
-    const resp = await fetch(this.apiEndpoint, {
-      method: "POST",
-      headers: {
-        Authorization: `Bearer ${this.OPENAI_API_KEY}`,
-        "Content-Type": "application/json",
-      },
-      body: JSON.stringify({
-        model: "gpt-3.5-turbo",
-        messages: [
-          { role: "system", content: this.sysMessageContent },
-          ...this.messages,
-        ],
-      }),
-    }).then((resp) => resp.json());
-    return resp;
+    const resp = await this._fetch();
+    return await resp.json();
   }
 
   async say(content: string): Promise<string> {
@@ -90,6 +101,14 @@ class Chat {
     );
   }
 
+  completeWithSteam() {
+    this.total_tokens =
+      this.messages
+        .map((msg) => this.calculate_token_length(msg.content) + 20)
+        .reduce((a, v) => a + v);
+    return this._fetch();
+  }
+
   // https://help.openai.com/en/articles/4936856-what-are-tokens-and-how-to-count-them
   calculate_token_length(content: string): number {
     const totalCount = content.length;