Reducers ও Actions — Cart Logic

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


interface CartState {
  items: CartItem[];
}

const initialState: CartState = { items: [] };

const cartSlice = createSlice({
  name: "cart",
  initialState,
  reducers: {
    addItem: (state, action: PayloadAction<{ productId: string; qty: number }>) => {
      const existing = state.items.find(
        (i) => i.productId === action.payload.productId,
      );
      if (existing) {
        existing.qty += action.payload.qty;
      } else {
        state.items.push(action.payload);
      }
    },

    increment: (state, action: PayloadAction<string>) => {
      const item = state.items.find((i) => i.productId === action.payload);
      if (item) item.qty += 1;
    },

    decrement: (state, action: PayloadAction<string>) => {
      const item = state.items.find((i) => i.productId === action.payload);
      if (item) {
        item.qty -= 1;
        if (item.qty <= 0) {
          state.items = state.items.filter(
            (i) => i.productId !== action.payload,
          );
        }
      }
    },

    removeItem: (state, action: PayloadAction<string>) => {
      state.items = state.items.filter(
        (i) => i.productId !== action.payload,
      );
    },

    clearCart: (state) => {
      state.items = [];
    },
  },
});

export const {
  addItem,
  increment,
  decrement,
  removeItem,
  clearCart,
} = cartSlice.actions;

export default cartSlice.reducer;