import { createSlice, PayloadAction } from '@reduxjs/toolkit';
import emitter from '../utils/eventEmitter';
import store from './store';
import { MqttMessage } from '../domain/mqttService';

export interface BusinessFlowState {
  currentKey: string;
  lastKey?: string; // Optional
  shouldKeepSelection?: boolean; // 🆕 标记是否应该保持选中的体位
  keptSelectionSopUid?: string; // 🆕 要保持选中的体位SOP UID
}

const initialState: BusinessFlowState = {
  currentKey: 'register',
  lastKey: '',
  shouldKeepSelection: false,
  keptSelectionSopUid: undefined,
};

const BusinessFlowSlice = createSlice({
  name: 'BusinessFlow',
  initialState,
  reducers: {
    setBusinessFlow: (state, action: PayloadAction<string>) => {
      const lastKey = state.currentKey; // Save the last key before changing
      
      // 🆕 只在 exam->process 的流程切换时保持标记（TASK_SUCCESS 场景）
      const isExamToProcess = lastKey === 'exam' && action.payload === 'process';
      
      return { 
        ...state,
        lastKey: lastKey, 
        currentKey: action.payload,
        // 🆕 exam->process 时保持标记，其他情况清除
        shouldKeepSelection: isExamToProcess ? state.shouldKeepSelection : false,
        keptSelectionSopUid: isExamToProcess ? state.keptSelectionSopUid : undefined,
      };
    },
    setKeepSelection: (state, action: PayloadAction<{ sopUid: string }>) => {
      state.shouldKeepSelection = true;
      state.keptSelectionSopUid = action.payload.sopUid;
      console.log(
        `[BusinessFlowSlice] setKeepSelection: ${action.payload.sopUid}`
      );
    },
    clearKeepSelection: (state) => {
      state.shouldKeepSelection = false;
      state.keptSelectionSopUid = undefined;
    },
  },
});

emitter.on('TASK_SUCCESS', (message: MqttMessage) => {
  console.log('[BusinessFlowSlice] TASK_SUCCESS received, switching to process');
  
  // 获取当前选中的体位
  const state = store.getState();
  const selectedBodyPosition = state.bodyPositionList.selectedBodyPosition;
  
  // 🆕 先标记要保持选中（在切换流程之前）
  if (selectedBodyPosition) {
    console.log(
      `[BusinessFlowSlice] Marking to keep selected position: ${selectedBodyPosition.sop_instance_uid}`
    );
    store.dispatch(setKeepSelection({ 
      sopUid: selectedBodyPosition.sop_instance_uid 
    }));
  }
  
  // 然后切换到 process 模式
  store.dispatch(setBusinessFlow('process'));
});

export const { setBusinessFlow, setKeepSelection, clearKeepSelection } = BusinessFlowSlice.actions;
export default BusinessFlowSlice.reducer;