import { createStore } from 'zustand/vanilla';
import { useSyncExternalStore } from 'react';

export type CheckoutStep = 'config' | 'shipping' | 'payment' | 'review' | 'confirmed';

export interface ShippingInfo {
  name: string;
  email: string;
  phone: string;
  address: string;
  city: string;
  country: string;
  postalCode: string;
}

export interface PaymentInfo {
  paymentIntentId: string;
  clientSecret: string;
  status: 'idle' | 'processing' | 'succeeded' | 'failed';
  errorMessage: string;
}

export interface PriceLineItem {
  label: string;
  price: number;
}

export interface OrderState {
  step: CheckoutStep;
  shipping: ShippingInfo;
  payment: PaymentInfo;
  orderId: string;
  orderTotal: number;
  personaSummary: string;
  colorSummary: string;
  priceItems: PriceLineItem[];
}

export interface OrderActions {
  setStep: (step: CheckoutStep) => void;
  setShipping: (shipping: ShippingInfo) => void;
  setPayment: (payment: Partial<PaymentInfo>) => void;
  setOrderTotal: (total: number) => void;
  setConfigSummary: (persona: string, color: string, priceItems?: PriceLineItem[]) => void;
  createPaymentIntent: () => Promise<string | null>;
  placeOrder: () => void;
  resetOrder: () => void;
}

export type OrderStore = OrderState & OrderActions;

const emptyShipping: ShippingInfo = {
  name: '',
  email: '',
  phone: '',
  address: '',
  city: '',
  country: '',
  postalCode: '',
};

const emptyPayment: PaymentInfo = {
  paymentIntentId: '',
  clientSecret: '',
  status: 'idle',
  errorMessage: '',
};

const defaultState: OrderState = {
  step: 'config',
  shipping: emptyShipping,
  payment: emptyPayment,
  orderId: '',
  orderTotal: 0,
  personaSummary: '',
  colorSummary: '',
  priceItems: [],
};

function generateOrderId(): string {
  const timestamp = Date.now().toString(36).toUpperCase();
  const random = Math.random().toString(36).substring(2, 6).toUpperCase();
  return `LR-G1-${timestamp}${random}`;
}

export const orderStore = createStore<OrderStore>((set) => ({
  ...defaultState,

  setStep: (step: CheckoutStep) => set({ step }),

  setShipping: (shipping: ShippingInfo) => set({ shipping }),

  setPayment: (payment: Partial<PaymentInfo>) => set((state) => ({
    payment: { ...state.payment, ...payment },
  })),

  setOrderTotal: (total: number) => set({ orderTotal: total }),

  setConfigSummary: (persona: string, color: string, priceItems: PriceLineItem[] = []) => set({
    personaSummary: persona,
    colorSummary: color,
    priceItems,
  }),

  createPaymentIntent: async (): Promise<string | null> => {
    const { orderTotal, personaSummary, colorSummary, shipping, priceItems } = orderStore.getState();
    try {
      const res: Response = await fetch('/api/create-payment-intent/', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          amount: orderTotal,
          currency: 'aed',
          receiptEmail: shipping.email || undefined,
          metadata: {
            persona: personaSummary,
            color: colorSummary,
            priceItems: JSON.stringify(priceItems),
            customerName: shipping.name,
            customerEmail: shipping.email,
            customerPhone: shipping.phone,
            customerAddress: shipping.address,
            customerCity: shipping.city,
            customerCountry: shipping.country,
            customerPostalCode: shipping.postalCode,
          },
        }),
      });
      const data: { clientSecret: string; paymentIntentId: string; error?: string } = await res.json();
      if (!res.ok) throw new Error(data.error || 'Failed to create payment intent');
      set({
        payment: {
          paymentIntentId: data.paymentIntentId,
          clientSecret: data.clientSecret,
          status: 'idle',
          errorMessage: '',
        },
      });
      return data.clientSecret;
    } catch (err) {
      const msg = err instanceof Error ? err.message : 'Payment initialization failed';
      set((s) => ({ payment: { ...s.payment, status: 'failed', errorMessage: msg } }));
      return null;
    }
  },

  placeOrder: () => set({
    orderId: generateOrderId(),
    step: 'confirmed',
  }),

  resetOrder: () => set({ ...defaultState }),
}));

export const useOrderStore = <T>(selector: (state: OrderStore) => T): T => {
  return useSyncExternalStore(
    orderStore.subscribe,
    () => selector(orderStore.getState()),
    () => selector(orderStore.getState())
  );
};