create common function stream for fetchEventSource

app/utils/chat.ts

@@ -1,5 +1,15 @@
-import { CACHE_URL_PREFIX, UPLOAD_URL } from "@/app/constant";
+import {
+  CACHE_URL_PREFIX,
+  UPLOAD_URL,
+  REQUEST_TIMEOUT_MS,
+} from "@/app/constant";
 import { RequestMessage } from "@/app/client/api";
+import Locale from "@/app/locales";
+import {
+  EventStreamContentType,
+  fetchEventSource,
+} from "@fortaine/fetch-event-source";
+import { prettyObject } from "./format";
 
 export function compressImage(file: Blob, maxSize: number): Promise<string> {
   return new Promise((resolve, reject) => {
@@ -142,3 +152,198 @@ export function removeImage(imageUrl: string) {
     credentials: "include",
   });
 }
+
+export function stream(
+  chatPath: string,
+  requestPayload: any,
+  headers: any,
+  tools: any[],
+  funcs: any,
+  controller: AbortController,
+  parseSSE: (text: string, runTools: any[]) => string | undefined,
+  options: any,
+) {
+  let responseText = "";
+  let remainText = "";
+  let finished = false;
+  let running = false;
+  let runTools: any[] = [];
+
+  // animate response to make it looks smooth
+  function animateResponseText() {
+    if (finished || controller.signal.aborted) {
+      responseText += remainText;
+      console.log("[Response Animation] finished");
+      if (responseText?.length === 0) {
+        options.onError?.(new Error("empty response from server"));
+      }
+      return;
+    }
+
+    if (remainText.length > 0) {
+      const fetchCount = Math.max(1, Math.round(remainText.length / 60));
+      const fetchText = remainText.slice(0, fetchCount);
+      responseText += fetchText;
+      remainText = remainText.slice(fetchCount);
+      options.onUpdate?.(responseText, fetchText);
+    }
+
+    requestAnimationFrame(animateResponseText);
+  }
+
+  // start animaion
+  animateResponseText();
+
+  const finish = () => {
+    if (!finished) {
+      console.log("try run tools", runTools.length, finished, running);
+      if (!running && runTools.length > 0) {
+        const toolCallMessage = {
+          role: "assistant",
+          tool_calls: [...runTools],
+        };
+        running = true;
+        runTools.splice(0, runTools.length); // empty runTools
+        return Promise.all(
+          toolCallMessage.tool_calls.map((tool) => {
+            options?.onBeforeTool?.(tool);
+            return Promise.resolve(
+              // @ts-ignore
+              funcs[tool.function.name](
+                // @ts-ignore
+                JSON.parse(tool.function.arguments),
+              ),
+            )
+              .then((content) => {
+                options?.onAfterTool?.({
+                  ...tool,
+                  content,
+                  isError: false,
+                });
+                return content;
+              })
+              .catch((e) => {
+                options?.onAfterTool?.({ ...tool, isError: true });
+                return e.toString();
+              })
+              .then((content) => ({
+                role: "tool",
+                content,
+                tool_call_id: tool.id,
+              }));
+          }),
+        ).then((toolCallResult) => {
+          console.log("end runTools", toolCallMessage, toolCallResult);
+          // @ts-ignore
+          requestPayload?.messages?.splice(
+            // @ts-ignore
+            requestPayload?.messages?.length,
+            0,
+            toolCallMessage,
+            ...toolCallResult,
+          );
+          setTimeout(() => {
+            // call again
+            console.log("start again");
+            running = false;
+            chatApi(chatPath, headers, requestPayload, tools); // call fetchEventSource
+          }, 60);
+        });
+        console.log("try run tools", runTools.length, finished);
+        return;
+      }
+      if (running) {
+        return;
+      }
+      finished = true;
+      options.onFinish(responseText + remainText);
+    }
+  };
+
+  controller.signal.onabort = finish;
+
+  function chatApi(
+    chatPath: string,
+    headers: any,
+    requestPayload: any,
+    tools: any,
+  ) {
+    const chatPayload = {
+      method: "POST",
+      body: JSON.stringify({
+        ...requestPayload,
+        tools,
+      }),
+      signal: controller.signal,
+      headers,
+    };
+    const requestTimeoutId = setTimeout(
+      () => controller.abort(),
+      REQUEST_TIMEOUT_MS,
+    );
+    fetchEventSource(chatPath, {
+      ...chatPayload,
+      async onopen(res) {
+        clearTimeout(requestTimeoutId);
+        const contentType = res.headers.get("content-type");
+        console.log("[Request] response content type: ", contentType);
+
+        if (contentType?.startsWith("text/plain")) {
+          responseText = await res.clone().text();
+          return finish();
+        }
+
+        if (
+          !res.ok ||
+          !res.headers
+            .get("content-type")
+            ?.startsWith(EventStreamContentType) ||
+          res.status !== 200
+        ) {
+          const responseTexts = [responseText];
+          let extraInfo = await res.clone().text();
+          try {
+            const resJson = await res.clone().json();
+            extraInfo = prettyObject(resJson);
+          } catch {}
+
+          if (res.status === 401) {
+            responseTexts.push(Locale.Error.Unauthorized);
+          }
+
+          if (extraInfo) {
+            responseTexts.push(extraInfo);
+          }
+
+          responseText = responseTexts.join("\n\n");
+
+          return finish();
+        }
+      },
+      onmessage(msg) {
+        if (msg.data === "[DONE]" || finished) {
+          return finish();
+        }
+        const text = msg.data;
+        try {
+          const chunk = parseSSE(msg.data, runTools);
+          if (chunk) {
+            remainText += chunk;
+          }
+        } catch (e) {
+          console.error("[Request] parse error", text, msg);
+        }
+      },
+      onclose() {
+        finish();
+      },
+      onerror(e) {
+        options?.onError?.(e);
+        throw e;
+      },
+      openWhenHidden: true,
+    });
+    console.log("chatApi", chatPath, requestPayload, tools);
+  }
+  chatApi(chatPath, headers, requestPayload, tools); // call fetchEventSource
+}