import { createSlice } from '@reduxjs/toolkit';

export const counterSlice = createSlice({
    name: 'counter',
    // 状态
    initialState: {
        value: 0,
    },
    // 修改的方法
    reducers: {
        increment: (state) => {
            // Redux Toolkit 允许我们在 reducers 中编写 mutating 逻辑。
            // 它实际上并没有 mutate state 因为它使用了 Immer 库，
            // 它检测到草稿 state 的变化并产生一个全新的基于这些更改的不可变 state
            state.value += 1;
        },
        decrement: (state) => {
            state.value -= 1;
        },
        incrementByAmount: (state, action) => {
            state.value += action.payload;
        },
    },
});

// 为每个 case reducer 函数生成 Action creators
export const { increment, decrement, incrementByAmount } = counterSlice.actions;

export default counterSlice.reducer;