refactor: Add frontend code to DB-GPT (#912)

web/hooks/use-chat.ts

@@ -0,0 +1,88 @@
+import { EventStreamContentType, fetchEventSource } from '@microsoft/fetch-event-source';
+import { message } from 'antd';
+import { useCallback, useEffect, useMemo } from 'react';
+import i18n from '@/app/i18n';
+
+type Props = {
+  queryAgentURL?: string;
+};
+
+type ChatParams = {
+  chatId: string;
+  data?: Record<string, any>;
+  onMessage: (message: string) => void;
+  onClose?: () => void;
+  onDone?: () => void;
+  onError?: (content: string, error?: Error) => void;
+};
+
+const useChat = ({ queryAgentURL = '/api/v1/chat/completions' }: Props) => {
+  const ctrl = useMemo(() => new AbortController(), []);
+
+  const chat = useCallback(
+    async ({ data, chatId, onMessage, onClose, onDone, onError }: ChatParams) => {
+      if (!data?.user_input && !data?.doc_id) {
+        message.warning(i18n.t('NoContextTip'));
+        return;
+      }
+
+      const parmas = {
+        ...data,
+        conv_uid: chatId,
+      };
+
+      if (!parmas.conv_uid) {
+        message.error('conv_uid 不存在，请刷新后重试');
+        return;
+      }
+
+      try {
+        await fetchEventSource(`${process.env.API_BASE_URL ?? ''}${queryAgentURL}`, {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/json',
+          },
+          body: JSON.stringify(parmas),
+          signal: ctrl.signal,
+          openWhenHidden: true,
+          async onopen(response) {
+            if (response.ok && response.headers.get('content-type') === EventStreamContentType) {
+              return;
+            }
+          },
+          onclose() {
+            ctrl.abort();
+            onClose?.();
+          },
+          onerror(err) {
+            throw new Error(err);
+          },
+          onmessage: (event) => {
+            const message = event.data?.replaceAll('\\n', '\n');
+            if (message === '[DONE]') {
+              onDone?.();
+            } else if (message?.startsWith('[ERROR]')) {
+              onError?.(message?.replace('[ERROR]', ''));
+            } else {
+              onMessage?.(message);
+            }
+          },
+        });
+      } catch (err) {
+        ctrl.abort();
+        onError?.('Sorry, We meet some error, please try agin later.', err as Error);
+      }
+    },
+    [queryAgentURL],
+  );
+
+  useEffect(() => {
+    return () => {
+      ctrl.abort();
+    };
+  }, []);
+
+  return chat;
+};
+
+export default useChat;