import { createAction, createReducer } from '@reduxjs/toolkit';
import { Order, OrderStatus, TrackingStep, DeliveryAgent, Location } from '../../../interfaces';

// ─── State ───────────────────────────────────────────────────────────────────

export interface OrderState {
  currentOrder: Order | null;
  orders: Order[];
  trackingSteps: TrackingStep[];
  deliveryAgent: DeliveryAgent | null;
  liveLocation: Location | null;
}

const initialState: OrderState = {
  currentOrder: null,
  orders: [],
  trackingSteps: [],
  deliveryAgent: null,
  liveLocation: null,
};

// ─── Helpers ─────────────────────────────────────────────────────────────────

const buildTrackingSteps = (status: OrderStatus): TrackingStep[] => {
  const steps: { key: OrderStatus; label: string }[] = [
    { key: 'placed', label: 'Order Placed' },
    { key: 'confirmed', label: 'Confirmed' },
    { key: 'dispatched', label: 'Dispatched' },
    { key: 'delivered', label: 'Delivered' },
  ];
  const currentIndex = steps.findIndex(s => s.key === status);
  return steps.map((step, index) => ({
    ...step,
    isCompleted: index < currentIndex,
    isActive: index === currentIndex,
  }));
};

// ─── Actions ─────────────────────────────────────────────────────────────────

export const placeOrder = createAction<Order>('order/placeOrder');
export const updateOrderStatus = createAction<OrderStatus>('order/updateOrderStatus');
export const setDeliveryAgent = createAction<DeliveryAgent>('order/setDeliveryAgent');
export const updateLiveLocation = createAction<Location>('order/updateLiveLocation');
export const addOrder = createAction<Order>('order/addOrder');

// ─── Reducer ─────────────────────────────────────────────────────────────────

const orderReducer = createReducer(initialState, builder => {
  builder
    .addCase(placeOrder, (state, action) => {
      state.currentOrder = action.payload;
      state.orders.unshift(action.payload);
      state.trackingSteps = buildTrackingSteps('placed');
    })
    .addCase(updateOrderStatus, (state, action) => {
      if (state.currentOrder) {
        state.currentOrder.status = action.payload;
        state.trackingSteps = buildTrackingSteps(action.payload);
        const idx = state.orders.findIndex(
          o => o.id === state.currentOrder!.id,
        );
        if (idx !== -1) {
          state.orders[idx] = {
            ...state.orders[idx],
            status: action.payload,
          };
        }
      }
    })
    .addCase(setDeliveryAgent, (state, action) => {
      state.deliveryAgent = action.payload;
    })
    .addCase(updateLiveLocation, (state, action) => {
      state.liveLocation = action.payload;
    })
    .addCase(addOrder, (state, action) => {
      state.orders.unshift(action.payload);
    });
});

export default orderReducer;