import { useCallback } from 'react';
import { ensureDMConverse } from '../../helper/converse-helper';
import { useAsync } from '../../hooks/useAsync';
import { showErrorToasts } from '../../manager/ui';
import {
  fetchConverseMessage,
  sendMessage,
  SendMessagePayload,
} from '../../model/message';
import { chatActions } from '../slices';
import { useAppDispatch, useAppSelector } from './useAppSelector';

/**
 * 会话消息管理
 */
export function useConverseMessage(converseId: string) {
  const converse = useAppSelector((state) => state.chat.converses[converseId]);
  const dispatch = useAppDispatch();
  const messages = converse?.messages ?? [];

  const { loading, error } = useAsync(async () => {
    if (!converse) {
      // 如果是一个新会话(或者当前会话列表中没有)

      // Step 1. 创建会话 并确保私信列表中存在该会话
      const converse = await ensureDMConverse(converseId);
      dispatch(chatActions.setConverseInfo(converse));

      // Step 2. 拉取消息
      const messages = await fetchConverseMessage(converseId);
      dispatch(
        chatActions.appendConverseMessage({
          converseId,
          messages,
        })
      );
    }
  }, [converse, converseId]);

  const handleSendMessage = useCallback(async (payload: SendMessagePayload) => {
    // TODO: 增加临时消息, 对网络环境不佳的状态进行优化

    try {
      const message = await sendMessage(payload);
      dispatch(
        chatActions.appendConverseMessage({
          converseId,
          messages: [message],
        })
      );
    } catch (err) {
      showErrorToasts(err);
    }
  }, []);

  return { messages, loading, error, handleSendMessage };
}